diff --git a/.idea/compiler.xml b/.idea/compiler.xml
index 61a9130..fb7f4a8 100644
--- a/.idea/compiler.xml
+++ b/.idea/compiler.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="CompilerConfiguration">
-    <bytecodeTargetLevel target="1.8" />
+    <bytecodeTargetLevel target="11" />
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/dictionaries/rumia.xml b/.idea/dictionaries/rumia.xml
index 8708a95..dff7651 100644
--- a/.idea/dictionaries/rumia.xml
+++ b/.idea/dictionaries/rumia.xml
@@ -2,6 +2,7 @@
   <dictionary name="rumia">
     <words>
       <w>copymanga</w>
+      <w>fileprovider</w>
       <w>fumiama</w>
     </words>
   </dictionary>
diff --git a/.idea/misc.xml b/.idea/misc.xml
index d5d35ec..860da66 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/.idea/runConfigurations.xml b/.idea/runConfigurations.xml
index 7f68460..e497da9 100644
--- a/.idea/runConfigurations.xml
+++ b/.idea/runConfigurations.xml
@@ -3,6 +3,7 @@
   <component name="RunConfigurationProducerService">
     <option name="ignoredProducers">
       <set>
+        <option value="com.android.tools.idea.compose.preview.runconfiguration.ComposePreviewRunConfigurationProducer" />
         <option value="org.jetbrains.plugins.gradle.execution.test.runner.AllInPackageGradleConfigurationProducer" />
         <option value="org.jetbrains.plugins.gradle.execution.test.runner.TestClassGradleConfigurationProducer" />
         <option value="org.jetbrains.plugins.gradle.execution.test.runner.TestMethodGradleConfigurationProducer" />
diff --git a/app/.gitignore b/app/.gitignore
index 42afabf..956c004 100644
--- a/app/.gitignore
+++ b/app/.gitignore
@@ -1 +1,2 @@
-/build
\ No newline at end of file
+/build
+/release
\ No newline at end of file
diff --git a/app/build.gradle b/app/build.gradle
index 40f8079..94b1f62 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -28,8 +28,8 @@ android {
         applicationId 'top.fumiama.copymanga'
         minSdkVersion 23
         targetSdkVersion 30
-        versionCode 12
-        versionName '2.0.beta'
+        versionCode 13
+        versionName '2.0.beta2'
         resConfigs "zh", "zh-rCN"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -80,10 +80,10 @@ dependencies {
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
     implementation 'com.google.android.material:material:1.3.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
-    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.3'
-    implementation 'androidx.navigation:navigation-ui-ktx:2.3.3'
-    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.3'
-    implementation 'androidx.navigation:navigation-ui-ktx:2.3.3'
+    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.5'
+    implementation 'androidx.navigation:navigation-ui-ktx:2.3.5'
+    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.5'
+    implementation 'androidx.navigation:navigation-ui-ktx:2.3.5'
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
@@ -132,7 +132,7 @@ andResGuard {
             "resources.arsc"
     ]
     sevenzip {
-        artifact = 'com.tencent.mm:SevenZip:1.2.20'
-        //path = "/usr/local/bin/7za"
+        //artifact = 'com.tencent.mm:SevenZip:1.2.20'
+        path = "7za"
     }
 }
\ No newline at end of file
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 994a910..ea186c3 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -5,6 +5,7 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
     <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES"/>
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
diff --git a/app/src/main/java/top/fumiama/copymanga/MainActivity.kt b/app/src/main/java/top/fumiama/copymanga/MainActivity.kt
index de7fc9a..3600ab0 100644
--- a/app/src/main/java/top/fumiama/copymanga/MainActivity.kt
+++ b/app/src/main/java/top/fumiama/copymanga/MainActivity.kt
@@ -34,7 +34,9 @@ import kotlinx.android.synthetic.main.app_bar_main.*
 import kotlinx.android.synthetic.main.nav_header_main.*
 import top.fumiama.dmzj.copymanga.R
 import top.fumiama.copymanga.tools.PropertiesTools
+import top.fumiama.copymanga.tools.UITools
 import top.fumiama.copymanga.ui.download.DownloadFragment
+import top.fumiama.copymanga.update.Update
 import java.io.File
 import java.io.FileInputStream
 import java.lang.ref.WeakReference
@@ -88,6 +90,7 @@ class MainActivity : AppCompatActivity() {
             override fun onDrawerSlide(drawerView: View, slideOffset: Float) {}
             override fun onDrawerStateChanged(newState: Int) {}
         })
+        checkUpdate(false)
     }
 
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
@@ -228,6 +231,11 @@ class MainActivity : AppCompatActivity() {
             )
         )
 
+    private fun checkUpdate(ignoreSkip: Boolean) {
+        Thread{
+            Update.checkUpdate(this, p, UITools(this), ignoreSkip)
+        }.start()
+    }
 
     fun showAbout(item: MenuItem) {
         val dl = android.app.AlertDialog.Builder(this)
@@ -235,6 +243,9 @@ class MainActivity : AppCompatActivity() {
         dl.setTitle(R.string.action_info)
         dl.setIcon(R.mipmap.ic_launcher)
         dl.setPositiveButton(android.R.string.ok) { _, _ -> }
+        dl.setNeutralButton(R.string.check_update) {_, _ ->
+            checkUpdate(true)
+        }
         dl.show()
     }
 
diff --git a/app/src/main/java/top/fumiama/copymanga/json/ThemeStructure.java b/app/src/main/java/top/fumiama/copymanga/json/ThemeStructure.java
index b2ae915..b573d4f 100644
--- a/app/src/main/java/top/fumiama/copymanga/json/ThemeStructure.java
+++ b/app/src/main/java/top/fumiama/copymanga/json/ThemeStructure.java
@@ -3,4 +3,5 @@ package top.fumiama.copymanga.json;
 public class ThemeStructure {
     public String name;
     public String path_word;
+    public int count;
 }
diff --git a/app/src/main/java/top/fumiama/copymanga/tools/CMApi.kt b/app/src/main/java/top/fumiama/copymanga/tools/CMApi.kt
index 6e6fb99..58365cc 100644
--- a/app/src/main/java/top/fumiama/copymanga/tools/CMApi.kt
+++ b/app/src/main/java/top/fumiama/copymanga/tools/CMApi.kt
@@ -15,4 +15,5 @@ object CMApi {
     fun getImgZipFileFromVM(exDir: File?, chapter2Return: Chapter2Return?) = File(exDir, "${chapter2Return?.results?.comic?.name}/${chapter2Return?.results?.chapter?.group_path_word}/${chapter2Return?.results?.chapter?.name}.zip")
     fun getZipFile(exDir: File?, manga: String, caption: CharSequence, name: CharSequence) = File(exDir, "$manga/$caption/$name.zip")
     fun getApiUrl(id: Int, arg1: String?, arg2: String?) = MainActivity.mainWeakReference?.get()?.getString(id)?.let { String.format(it, arg1, arg2) }
+    fun getApiUrl(id: Int, arg1: String?, arg2: String?, arg3: Int? = 0) = MainActivity.mainWeakReference?.get()?.getString(id)?.let { String.format(it, arg1, arg2, arg3) }
 }
\ No newline at end of file
diff --git a/app/src/main/java/top/fumiama/copymanga/tools/PropertiesTools.kt b/app/src/main/java/top/fumiama/copymanga/tools/PropertiesTools.kt
index be5dcf1..feb7246 100644
--- a/app/src/main/java/top/fumiama/copymanga/tools/PropertiesTools.kt
+++ b/app/src/main/java/top/fumiama/copymanga/tools/PropertiesTools.kt
@@ -1,52 +1,63 @@
 package top.fumiama.copymanga.tools
 //PropertiesTools.kt
 //created by fumiama 20200724
+import android.util.Log
 import java.io.File
 import java.io.InputStream
 import java.util.*
 
 class PropertiesTools(private val f: File):Properties() {
-    private val propfile:File
-        get() {
-            if(!f.exists()) {
-                if(f.parentFile?.exists() != true) f.parentFile?.mkdirs()
-                if(f.parentFile?.canWrite() != true) f.parentFile?.setWritable(true)
-                createNew(f)
-            }else if(f.isDirectory) {
-                if(f.parentFile?.canWrite() != true) f.parentFile?.setWritable(true)
-                f.delete()
-                createNew(f)
-            }
+    private var cache = hashMapOf<String, String>()
+
+    init {
+        if(!f.exists()) {
+            if(f.parentFile?.exists() != true) f.parentFile?.mkdirs()
             if(f.parentFile?.canWrite() != true) f.parentFile?.setWritable(true)
-            if(f.parentFile?.canRead() != true) f.parentFile?.setReadable(true)
-            return f
+            createNew(f)
+        } else if(f.isDirectory) {
+            if(f.parentFile?.canWrite() != true) f.parentFile?.setWritable(true)
+            f.delete()
+            createNew(f)
         }
-    private fun createNew(f: File){
+        if(f.parentFile?.canWrite() != true) f.parentFile?.setWritable(true)
+        if(f.parentFile?.canRead() != true) f.parentFile?.setReadable(true)
+    }
+
+    private fun createNew(f: File) {
         f.createNewFile()
         val o = f.outputStream()
         this.storeToXML(o, "store")
-        //Log.d("MyPT", "Generate new prop.")
+        Log.d("MyPT", "Generate new prop.")
         o.close()
     }
+
     private fun loadFromXml(`in`: InputStream?): PropertiesTools {
         this.loadFromXML(`in`)
         return this
     }
+
     private fun setProp(key: String?, value: String?): PropertiesTools {
         this.setProperty(key, value)
         return this
     }
+
     operator fun get(key: String): String{
-        val i = propfile.inputStream()
-        val re = this.loadFromXml(i).getProperty(key)?:"null"
-        //Log.d("MyPT", "Get prop: $re")
-        i.close()
-        return re
+        return if(cache.containsKey(key)) cache[key]?:"null"
+        else {
+            val i = f.inputStream()
+            val re = this.loadFromXml(i).getProperty(key)?:"null"
+            Log.d("MyPT", "Read $key = $re")
+            i.close()
+            cache[key] = re
+            re
+        }
     }
-    operator fun set(key: String, value: String){
-        val o = propfile.outputStream()
+
+    operator fun set(key: String, value: String) {
+        cache[key] = value
+        val o = f.outputStream()
         this.setProp(key, value).storeToXML(o, "store")
-        //Log.d("MyPT", "Set $key = $value")
+        Log.d("MyPT", "Set $key = $value")
         o.close()
     }
 }
diff --git a/app/src/main/java/top/fumiama/copymanga/tools/UITools.kt b/app/src/main/java/top/fumiama/copymanga/tools/UITools.kt
index 3ffb301..640e7cf 100644
--- a/app/src/main/java/top/fumiama/copymanga/tools/UITools.kt
+++ b/app/src/main/java/top/fumiama/copymanga/tools/UITools.kt
@@ -5,6 +5,7 @@ import android.app.AlertDialog
 import android.content.Context
 import android.net.ConnectivityManager
 import android.net.NetworkCapabilities
+import android.view.View
 import android.widget.Toast
 import top.fumiama.dmzj.copymanga.R
 import java.lang.ref.WeakReference
@@ -53,6 +54,26 @@ class UITools(that: Context?, w: WeakReference<Activity>? = null) {
         txtN?.let { info.setNeutralButton(it) { _, _ -> neutral?.let { it() } } }
         info.show()
     }
+    fun buildAlertWithView(
+        title: String,
+        view: View,
+        txtOk: String? = null,
+        txtN: String? = null,
+        txtCancel: String? = null,
+        ok: (() -> Unit)? = null,
+        neutral: (() -> Unit)? = null,
+        cancel: (() -> Unit)? = null
+    ): AlertDialog {
+        val info = AlertDialog.Builder(zis)
+        info.setIcon(R.drawable.ic_launcher_foreground)
+        info.setTitle(title)
+
+        info.setView(view)
+        txtOk?.let { info.setPositiveButton(it) { _, _ -> ok?.let { it() } } }
+        txtCancel?.let { info.setNegativeButton(it) { _, _ -> cancel?.let { it() } } }
+        txtN?.let { info.setNeutralButton(it) { _, _ -> neutral?.let { it() } } }
+        return info.show()
+    }
     fun dp2px(dp:Int):Int?{
         return zis?.resources?.displayMetrics?.density?.let { (dp * it + 0.5).toInt()}
     }
@@ -85,4 +106,14 @@ class UITools(that: Context?, w: WeakReference<Activity>? = null) {
         val totalWidth = ((zis?.resources?.displayMetrics?.widthPixels?:1080)-marginPx)/numPerRow
         return listOf(numPerRow, w, totalWidth)
     }
+    fun toHexStr(byteArray: ByteArray) =
+        with(StringBuilder()) {
+            byteArray.forEach {
+                val hex = it.toInt() and (0xFF)
+                val hexStr = Integer.toHexString(hex)
+                if (hexStr.length == 1) append("0").append(hexStr)
+                else append(hexStr)
+            }
+            toString()
+        }
 }
\ No newline at end of file
diff --git a/app/src/main/java/top/fumiama/copymanga/ui/book/BookFragment.kt b/app/src/main/java/top/fumiama/copymanga/ui/book/BookFragment.kt
index 44313a3..266afbb 100644
--- a/app/src/main/java/top/fumiama/copymanga/ui/book/BookFragment.kt
+++ b/app/src/main/java/top/fumiama/copymanga/ui/book/BookFragment.kt
@@ -61,12 +61,16 @@ class BookFragment:NoBackRefreshFragment(R.layout.fragment_book) {
         val groups = bookHandler.book?.results?.groups
         var keys = arrayOf<String>()
         var gpws = arrayOf<String>()
+        var cnts = intArrayOf()
         groups?.values?.forEach {
             keys += it.name
             gpws += it.path_word
+            cnts += it.count
+            Log.d("MyBF", "Add caption: ${it.name} @ ${it.path_word} of ${it.count}")
         }
         bundle.putStringArray("group", gpws)
         bundle.putStringArray("groupNames", keys)
+        bundle.putIntArray("count", cnts)
         rootView?.let { Navigation.findNavController(it).navigate(R.id.action_nav_book_to_nav_group, bundle) }
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/top/fumiama/copymanga/ui/comicdl/ComicDlFragment.kt b/app/src/main/java/top/fumiama/copymanga/ui/comicdl/ComicDlFragment.kt
index 5881d1e..3f40fd4 100644
--- a/app/src/main/java/top/fumiama/copymanga/ui/comicdl/ComicDlFragment.kt
+++ b/app/src/main/java/top/fumiama/copymanga/ui/comicdl/ComicDlFragment.kt
@@ -10,6 +10,7 @@ import android.view.View
 import com.google.gson.Gson
 import top.fumiama.dmzj.copymanga.R
 import top.fumiama.copymanga.MainActivity.Companion.mainWeakReference
+import top.fumiama.copymanga.json.ChapterStructure
 import top.fumiama.copymanga.json.VolumeStructure
 import top.fumiama.copymanga.template.AutoDownloadThread
 import top.fumiama.copymanga.template.NoBackRefreshFragment
@@ -32,7 +33,8 @@ class ComicDlFragment:NoBackRefreshFragment(R.layout.fragment_dlcomic) {
                 }
                 else -> initComicData(
                     arguments?.getString("path"),
-                    arguments?.getStringArray("group")
+                    arguments?.getStringArray("group"),
+                    arguments?.getIntArray("count")
                 )
             }
         }
@@ -44,7 +46,7 @@ class ComicDlFragment:NoBackRefreshFragment(R.layout.fragment_dlcomic) {
         mainWeakReference?.get()?.menuMain?.let { setMenuInvisible(it) }
     }*/
 
-    fun start2load(volumes: Array<VolumeStructure>, isFromFile: Boolean = false, groupArray: Array<String>? =null){
+    private fun start2load(volumes: Array<VolumeStructure>, isFromFile: Boolean = false, groupArray: Array<String>? =null){
         handler = ComicDlHandler(Looper.myLooper()!!,
             WeakReference(this),
             volumes,
@@ -85,21 +87,42 @@ class ComicDlFragment:NoBackRefreshFragment(R.layout.fragment_dlcomic) {
         menu.findItem(R.id.action_download)?.isVisible = false
     }*/
 
-    private fun initComicData(pw: String?, gpws: Array<String>?) {
-        var volumes = arrayOf<VolumeStructure>()
-        val waitHandler = WaitHandler(WeakReference(this))
+    private fun initComicData(pw: String?, gpws: Array<String>?, counts: IntArray?) {
+        var volumes = emptyArray<VolumeStructure>()
         if (gpws != null) {
-            gpws.forEach { gpw ->
+            gpws.forEachIndexed { i, gpw ->
                 Log.d("MyCDF", "下载:$gpw")
-                CMApi.getApiUrl(R.string.groupInfoApiUrl, pw, gpw)?.let {
-                    AutoDownloadThread(it) { result ->
-                        //Log.d("MyCDF", "返回:${result?.decodeToString()}")
-                        volumes += Gson().fromJson(
-                            result?.decodeToString(),
-                            VolumeStructure::class.java
-                        )
-                    }.start()
-                }
+                var offset = 0
+                val re = arrayOfNulls<VolumeStructure>(counts?.get(i)?:1)
+                do {
+                    counts?.set(i, counts[i] - 100)
+                    CMApi.getApiUrl(R.string.groupInfoApiUrl, pw, gpw, offset)?.let {
+                        AutoDownloadThread(it) { result ->
+                            //Log.d("MyCDF", "返回:${result?.decodeToString()}")
+                            val r = Gson().fromJson(result?.decodeToString(), VolumeStructure::class.java)
+                            re[r.results.offset / 100] = r
+                        }.start()
+                        offset += 100
+                    }
+                } while ((counts?.get(i) ?: 0) > 0)
+                Thread {
+                    var c = 0
+                    while (c++ < 80) {
+                        sleep(100)
+                        if(re.all { it != null }) break
+                    }
+                    if(re.size > 1) {
+                        val r = re[0]
+                        var s = emptyArray<ChapterStructure>()
+                        re.forEach {
+                            it?.results?.list?.forEach {
+                                s += it
+                            }
+                        }
+                        r?.results?.list = s
+                        r?.apply { volumes += this }
+                    } else re[0]?.apply { volumes += this }
+                }.start()
             }
             Thread {
                 var c = 0
@@ -109,7 +132,9 @@ class ComicDlFragment:NoBackRefreshFragment(R.layout.fragment_dlcomic) {
                     c++
                 }
                 if (volumes.size == gpws.size) {
-                    waitHandler.obtainMessage(0, volumes).sendToTarget()
+                    mainWeakReference?.get()?.runOnUiThread {
+                        start2load(volumes)
+                    }
                 }
             }.start()
         }
@@ -122,15 +147,6 @@ class ComicDlFragment:NoBackRefreshFragment(R.layout.fragment_dlcomic) {
         handler?.startLoad()
     }
 
-    class WaitHandler(private val that: WeakReference<ComicDlFragment>): Handler(Looper.myLooper()!!){
-        override fun handleMessage(msg: Message) {
-            super.handleMessage(msg)
-            when(msg.what){
-                0 -> that.get()?.start2load(msg.obj as Array<VolumeStructure>)
-            }
-        }
-    }
-
     companion object {
         var json: String? = null
     }
diff --git a/app/src/main/java/top/fumiama/copymanga/update/Client.kt b/app/src/main/java/top/fumiama/copymanga/update/Client.kt
new file mode 100644
index 0000000..f393c2b
--- /dev/null
+++ b/app/src/main/java/top/fumiama/copymanga/update/Client.kt
@@ -0,0 +1,139 @@
+package top.fumiama.copymanga.update
+
+import android.util.Log
+import java.io.IOException
+import java.io.InputStream
+import java.io.OutputStream
+import java.net.Socket
+
+class Client(private val ip: String, private val port: Int) {
+    //普通数据交互接口
+    private var sc: Socket? = null
+
+    //普通交互流
+    private var dout: OutputStream? = null
+    private var din: InputStream? = null
+
+    //已连接标记
+    private val isConnect get() = sc != null && din != null && dout != null
+
+    /**
+     * 初始化普通交互连接
+     */
+    fun initConnect(depth: Int = 0): Boolean{
+        if(depth > 3) Log.d("MyC", "connect server failed after $depth tries")
+        else try {
+            sc = Socket(ip, port) //通过socket连接服务器
+            din = sc?.getInputStream()  //获取输入流并转换为StreamReader，约定编码格式
+            dout = sc?.getOutputStream()    //获取输出流
+            sc?.soTimeout = 2333  //设置连接超时限制
+            return if (isConnect) {
+                Log.d("MyC", "connect server successful")
+                true
+            } else {
+                Log.d("MyC", "connect server failed, now retry...")
+                initConnect(depth + 1)
+            }
+        } catch (e: IOException) {      //获取输入输出流是可能报IOException的，所以必须try-catch
+            e.printStackTrace()
+        }
+        return false
+    }
+
+    /**
+     * 发送数据至服务器
+     * @param message 要发送至服务器的字符串
+     */
+    fun sendMessage(message: CharSequence?): Boolean {
+        try {
+            if (isConnect) {
+                if (message != null) {        //判断输出流或者消息是否为空，为空的话会产生nullpoint错误
+                    dout?.write(message.toString().toByteArray())
+                    dout?.flush()
+                    Log.d("MyC", "Send msg: $message")
+                    return true
+                } else Log.d("MyC", "The message to be sent is empty")
+                Log.d("MyC", "send message succeed")
+            } else Log.d("MyC", "send message failed: no connect")
+        } catch (e: IOException) {
+            Log.d("MyC", "send message failed: crash")
+            e.printStackTrace()
+        }
+        return false
+    }
+
+    var buffer = byteArrayOf()
+
+    fun receiveRawMessage(totalSize: Int = -1, bufferSize: Int = 1048576, setProgress: Boolean = false) : ByteArray {
+        if(totalSize == buffer.size) {
+            val re = buffer
+            buffer = byteArrayOf()
+            return re
+        } else {
+            var re = byteArrayOf()
+            try {
+                if (isConnect) {
+                    Log.d("MyC", "开始接收服务端信息")
+                    val inMessage = ByteArray(bufferSize)     //设置接受缓冲，避免接受数据过长占用过多内存
+                    var a: Int
+                    do {
+                        a = din?.read(inMessage)?:0 //a存储返回消息的长度
+                        if(a > 0) {
+                            re += inMessage.copyOf(a)
+                            Log.d("MyC", "reply length:$a")
+                            if(totalSize < 0 && a < bufferSize) break
+                            else if(setProgress && totalSize > 0) progress?.notify(100 * re.size / totalSize)
+                        } else break
+                    } while (totalSize > re.size)
+                } else Log.d("MyC", "no connect to receive message")
+            } catch (e: IOException) {
+                Log.d("MyC", "receive message failed")
+                e.printStackTrace()
+            }
+            if(totalSize > 0 && re.size > totalSize) {
+                Log.d("MyC", "Reduce re size from ${re.size} to $totalSize")
+                buffer += re.copyOfRange(totalSize, re.size)
+                re = re.copyOf(totalSize)
+            } else if(totalSize > 0 && buffer.isNotEmpty()) {
+                Log.d("MyC", "Increase re size.")
+                buffer += re
+                if(buffer.size > totalSize) {
+                    re = buffer.copyOf(totalSize)
+                    buffer = buffer.copyOfRange(totalSize, buffer.size)
+                } else {
+                    re = buffer
+                    buffer = byteArrayOf()
+                }
+            } else if(totalSize < 0 && buffer.isNotEmpty()) {
+                re = buffer
+                buffer = byteArrayOf()
+                Log.d("MyC", "clear buffer")
+            }
+            return re
+        }
+    }
+
+    //fun receiveMessage() = receiveRawMessage().decodeToString()
+
+    /**
+     * 关闭连接
+     */
+    fun closeConnect() = try {
+            din?.close()
+            dout?.close()
+            sc?.close()
+            sc = null
+            din = null
+            dout = null
+            true
+        } catch (e: IOException) {
+            e.printStackTrace()
+            false
+        }
+
+    var progress: Progress? = null
+
+    interface Progress {
+        fun notify(progressPercentage: Int)
+    }
+}
diff --git a/app/src/main/java/top/fumiama/copymanga/update/SimpleKanban.kt b/app/src/main/java/top/fumiama/copymanga/update/SimpleKanban.kt
new file mode 100644
index 0000000..293e0ea
--- /dev/null
+++ b/app/src/main/java/top/fumiama/copymanga/update/SimpleKanban.kt
@@ -0,0 +1,68 @@
+package top.fumiama.copymanga.update
+
+import android.util.Log
+
+class SimpleKanban(private val client: Client, private val pwd: String) {   //must run in thread
+    private val raw: ByteArray?
+        get() {
+            var times = 3
+            var re: ByteArray
+            var firstRecv: ByteArray
+            do {
+                re = byteArrayOf()
+                if(client.initConnect()) {
+                    client.sendMessage("${pwd}catquit")
+                    client.receiveRawMessage(33)    //Welcome to simple kanban server.
+                    try {
+                        firstRecv = client.receiveRawMessage(4)     //le
+                        val length = convert2Int(firstRecv)
+                        if(firstRecv.size > 4) re += firstRecv.copyOfRange(4, firstRecv.size)
+                        re += client.receiveRawMessage(length - re.size, setProgress = true)
+                        break
+                    } catch (e: Exception) {
+                        e.printStackTrace()
+                    }
+                    client.closeConnect()
+                }
+            } while (times-- > 0)
+            return if(re.isEmpty()) null else re
+        }
+
+    private fun convert2Int(buffer: ByteArray) =
+            (buffer[3].toInt() and 0xff shl 24) or
+            (buffer[2].toInt() and 0xff shl 16) or
+            (buffer[1].toInt() and 0xff shl 8) or
+            (buffer[0].toInt() and 0xff)
+
+    fun fetchRaw(doOnLoadFailure: ()->Unit = {
+        Log.d("MySD", "Fetch dict failed")
+    }, doOnLoadSuccess: (data: ByteArray)->Unit = {
+        Log.d("MySD", "Fetch dict success")
+    }) {
+        raw?.apply {
+            doOnLoadSuccess(this)
+        }?:doOnLoadFailure()
+    }
+
+    operator fun get(version: Int): String =
+        if(client.initConnect()) {
+            client.sendMessage("${pwd}get${version}quit")
+            client.receiveRawMessage(36)             //Welcome to simple kanban server. get
+            val r = try {
+                val firstRecv = client.receiveRawMessage(4)
+                if(firstRecv.decodeToString() == "null") "null"
+                else {
+                    val length = convert2Int(firstRecv)
+                    var re = byteArrayOf()
+                    if(firstRecv.size > 4) re += firstRecv.copyOfRange(4, firstRecv.size)
+                    re += client.receiveRawMessage(length - re.size)
+                    if(re.isNotEmpty()) re.decodeToString() else "null"
+                }
+            } catch (e: Exception){
+                e.printStackTrace()
+                "null"
+            }
+            client.closeConnect()
+            r
+        } else "null"
+}
\ No newline at end of file
diff --git a/app/src/main/java/top/fumiama/copymanga/update/Update.kt b/app/src/main/java/top/fumiama/copymanga/update/Update.kt
new file mode 100644
index 0000000..375e862
--- /dev/null
+++ b/app/src/main/java/top/fumiama/copymanga/update/Update.kt
@@ -0,0 +1,87 @@
+package top.fumiama.copymanga.update
+
+import android.app.Activity
+import android.content.Intent
+import android.net.Uri
+import android.os.Build
+import android.util.Log
+import android.widget.Toast
+import androidx.core.content.FileProvider
+import kotlinx.android.synthetic.main.dialog_progress.view.*
+import top.fumiama.copymanga.tools.PropertiesTools
+import top.fumiama.copymanga.tools.UITools
+import top.fumiama.dmzj.copymanga.R
+import java.io.File
+import java.security.MessageDigest
+
+object Update {
+    fun checkUpdate(activity: Activity, p: PropertiesTools, toolsBox: UITools, ignoreSkip: Boolean = false) = activity.apply{
+        val client = Client("copymanga.v6.army", 12315)
+        val progressBar = layoutInflater.inflate(R.layout.dialog_progress, null, false)
+        val progressHandler = object : Client.Progress{
+            override fun notify(progressPercentage: Int) {
+                Log.d("MyUP", "Set progress: $progressPercentage")
+                progressBar.dpp.progress = progressPercentage
+            }
+        }
+        val kanban = SimpleKanban(client, "fumiama")
+        val msg = kanban[packageManager.getPackageInfo(packageName, 0).versionCode]
+        if(msg != "null") {
+            val verNum = msg.substringBefore('\n').toIntOrNull()
+            val skipNum = p["skipVersion"].let { if(it != "null") it.toInt() else 0 }
+
+            Log.d("MyUP", "Ver:$verNum, skip: $skipNum")
+            if(verNum != null) {
+                if(msg.contains("md5:")) {
+                    if(skipNum < verNum || ignoreSkip) runOnUiThread {
+                        toolsBox.buildInfo("看板", msg.substringAfter('\n').substringBeforeLast('\n'), "下载新版", "跳过该版", "取消", {
+                            val info = toolsBox.buildAlertWithView("下载进度", progressBar, "隐藏")
+                            client.progress = progressHandler
+                            Thread {
+                                kanban.fetchRaw({
+                                    runOnUiThread {
+                                        Toast.makeText(this, "下载失败", Toast.LENGTH_SHORT).show()
+                                        client.progress = null
+                                    }
+                                }) {
+                                    val md5 = msg.substringAfterLast("md5:")
+                                    if (md5 == toolsBox.toHexStr(
+                                            MessageDigest.getInstance("MD5").digest(it)
+                                        )
+                                    ) {
+                                        runOnUiThread {
+                                            Toast.makeText(this, "下载成功", Toast.LENGTH_SHORT).show()
+                                            info.dismiss()
+                                        }
+                                        val f = File(externalCacheDir, "new.apk")
+                                        f.writeBytes(it)
+                                        install(f, activity)
+                                    } else runOnUiThread {
+                                        Toast.makeText(this, "文件损坏", Toast.LENGTH_SHORT).show()
+                                        info.dismiss()
+                                    }
+                                    client.progress = null
+                                }
+                            }.start()
+                        }, { p["skipVersion"] = verNum.toString() })
+                    }
+                } else runOnUiThread {
+                    toolsBox.buildInfo("看板", msg.substringAfter('\n'), "知道了")
+                }
+            }
+        } else if(ignoreSkip) runOnUiThread {
+            Toast.makeText(this, "无更新", Toast.LENGTH_SHORT).show()
+        }
+    }
+
+    private fun install(apkFile: File, activity: Activity) = activity.apply{
+        val intent = Intent(Intent.ACTION_VIEW)
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+            val contentUri: Uri = FileProvider.getUriForFile(this, "$packageName.fileprovider", apkFile)
+            intent.setDataAndType(contentUri, "application/vnd.android.package-archive")
+        } else intent.setDataAndType(Uri.fromFile(apkFile), "application/vnd.android.package-archive")
+        startActivity(intent)
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/res/layout/dialog_progress.xml b/app/src/main/res/layout/dialog_progress.xml
new file mode 100644
index 0000000..3ff07dd
--- /dev/null
+++ b/app/src/main/res/layout/dialog_progress.xml
@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content">
+
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:layout_marginStart="24dp"
+        android:layout_marginTop="8dp"
+        android:layout_marginEnd="24dp"
+        android:background="@drawable/rndbg_white"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent">
+
+        <ImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:src="@drawable/ic_dere"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent" />
+
+        <ProgressBar
+            android:id="@+id/dpp"
+            style="?android:attr/progressBarStyleHorizontal"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_marginStart="32dp"
+            android:layout_marginEnd="32dp"
+            android:progress="0"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent" />
+
+    </androidx.constraintlayout.widget.ConstraintLayout>
+
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index edca884..3586fb7 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -15,6 +15,7 @@
     <string name="page_book">图书详情</string>
     <string name="page_chapter">章节内容</string>
     <string name="page_group">漫画下载</string>
+    <string name="check_update">检查更新</string>
 
     <string name="navTextInfo">illust: Hiten(490219)</string>
     <string name="navTextInfoInputHint">请设定提示文字内容</string>
@@ -34,7 +35,7 @@
     <string name="filterApiUrl">https://api.copymanga.com/api/v3/h5/filterIndex/comic/tags</string>
     <string name="sortApiUrl">https://api.copymanga.com/api/v3/comics?limit=21&amp;offset=%1$d&amp;ordering=%2$s&amp;theme=%3$s</string>
     <string name="bookInfoApiUrl">https://api.copymanga.com/api/v3/comic2/%1$s</string>
-    <string name="groupInfoApiUrl">https://api.copymanga.com/api/v3/comic/%1$s/group/%2$s/chapters</string>
+    <string name="groupInfoApiUrl">https://api.copymanga.com/api/v3/comic/%1$s/group/%2$s/chapters?limit=100&amp;offset=%3$d</string>
     <string name="chapterInfoApiUrl">https://api.copymanga.com/api/v3/comic/%1$s/chapter2/%2$s</string>
     <string name="chapterTxtUrl">https://nnv3api.dmzj1.com/novel/download/%1$d_%2$d_%3$d.txt</string>
 
diff --git a/app/src/main/res/xml/provider_paths.xml b/app/src/main/res/xml/provider_paths.xml
index c3e47b3..c1a5d89 100644
--- a/app/src/main/res/xml/provider_paths.xml
+++ b/app/src/main/res/xml/provider_paths.xml
@@ -1,4 +1,5 @@
 <paths>
     <external-files-path name="ef" path="."/>
     <files-path name="if" path="."/>
+    <external-cache-path name="ec" path="."/>
 </paths>
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index b7e45fb..8dc9e1f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,6 +1,6 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
-    ext.kotlin_version = '1.4.31'
+    ext.kotlin_version = '1.5.0'
     repositories {
         google()
         jcenter()
@@ -8,9 +8,9 @@ buildscript {
         maven { url 'https://maven.google.com' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.1.2'
+        classpath 'com.android.tools.build:gradle:4.2.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-        classpath 'com.tencent.mm:AndResGuard-gradle-plugin:1.2.20'
+        classpath 'com.tencent.mm:AndResGuard-gradle-plugin:1.2.21'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files