diff --git a/app/src/main/assets/updateLog.md b/app/src/main/assets/updateLog.md
index 482907c7c..d6a435788 100644
--- a/app/src/main/assets/updateLog.md
+++ b/app/src/main/assets/updateLog.md
@@ -8,6 +8,7 @@
 * 解决看过书籍的移到顶部需要向上滚动才能看到的bug
 * 只有再书源被删除找不到书源时才会自动换源
 * 美化界面by yangyxd
+* 订阅后台播放
 
 **2020/03/16**
 * 修复滚动模式切换章节位置不归0的bug
diff --git a/app/src/main/java/io/legado/app/data/entities/Book.kt b/app/src/main/java/io/legado/app/data/entities/Book.kt
index 9e50a6d4c..0dd5cab9e 100644
--- a/app/src/main/java/io/legado/app/data/entities/Book.kt
+++ b/app/src/main/java/io/legado/app/data/entities/Book.kt
@@ -32,7 +32,7 @@ data class Book(
     var customIntro: String? = null,            // 简介内容(用户修改)
     var charset: String? = null,                // 自定义字符集名称(仅适用于本地书籍)
     var type: Int = 0,                          // 0:text 1:audio
-    var group: Int = 1,                         // 自定义分组索引号
+    var group: Int = 0,                         // 自定义分组索引号
     var latestChapterTitle: String? = null,     // 最新章节标题
     var latestChapterTime: Long = System.currentTimeMillis(),            // 最新章节标题更新时间
     var lastCheckTime: Long = System.currentTimeMillis(),                // 最近一次更新书籍信息的时间
diff --git a/app/src/main/java/io/legado/app/help/coroutine/Coroutine.kt b/app/src/main/java/io/legado/app/help/coroutine/Coroutine.kt
index e9fd0df86..eb0a29375 100644
--- a/app/src/main/java/io/legado/app/help/coroutine/Coroutine.kt
+++ b/app/src/main/java/io/legado/app/help/coroutine/Coroutine.kt
@@ -6,7 +6,7 @@ import kotlin.coroutines.CoroutineContext
 
 
 class Coroutine<T>(
-    scope: CoroutineScope,
+    val scope: CoroutineScope,
     context: CoroutineContext = Dispatchers.IO,
     block: suspend CoroutineScope.() -> T
 ) {
@@ -31,6 +31,7 @@ class Coroutine<T>(
     private var success: Callback<T?>? = null
     private var error: Callback<Throwable>? = null
     private var finally: VoidCallback? = null
+    private var cancel: VoidCallback? = null
 
     private var timeMillis: Long? = null
     private var errorReturn: Result<T>? = null
@@ -45,7 +46,7 @@ class Coroutine<T>(
         get() = job.isCompleted
 
     init {
-        this.job = executeInternal(scope, context, block)
+        this.job = executeInternal(context, block)
     }
 
     fun timeout(timeMillis: () -> Long): Coroutine<T> {
@@ -100,9 +101,28 @@ class Coroutine<T>(
         return this@Coroutine
     }
 
+    fun onCancel(
+        context: CoroutineContext? = null,
+        block: suspend CoroutineScope.() -> Unit
+    ): Coroutine<T> {
+        this.cancel = VoidCallback(context, block)
+        return this@Coroutine
+    }
+
     //取消当前任务
     fun cancel(cause: CancellationException? = null) {
         job.cancel(cause)
+        cancel?.let {
+            MainScope().launch {
+                if (null == it.context) {
+                    it.block.invoke(scope)
+                } else {
+                    withContext(scope.coroutineContext.plus(it.context)) {
+                        it.block.invoke(this)
+                    }
+                }
+            }
+        }
     }
 
     fun invokeOnCompletion(handler: CompletionHandler): DisposableHandle {
@@ -110,7 +130,6 @@ class Coroutine<T>(
     }
 
     private fun executeInternal(
-        scope: CoroutineScope,
         context: CoroutineContext,
         block: suspend CoroutineScope.() -> T
     ): Job {
@@ -118,21 +137,27 @@ class Coroutine<T>(
             try {
                 start?.let { dispatchVoidCallback(this, it) }
                 val value = executeBlock(scope, context, timeMillis ?: 0L, block)
-                success?.let { dispatchCallback(this, value, it) }
+                if (isActive) {
+                    success?.let { dispatchCallback(this, value, it) }
+                }
             } catch (e: Throwable) {
                 if (BuildConfig.DEBUG) {
                     e.printStackTrace()
                 }
                 val consume: Boolean = errorReturn?.value?.let { value ->
-                    success?.let { dispatchCallback(this, value, it) }
+                    if (isActive) {
+                        success?.let { dispatchCallback(this, value, it) }
+                    }
                     true
                 } ?: false
 
-                if (!consume) {
+                if (!consume && isActive) {
                     error?.let { dispatchCallback(this, e, it) }
                 }
             } finally {
-                finally?.let { dispatchVoidCallback(this, it) }
+                if (isActive) {
+                    finally?.let { dispatchVoidCallback(this, it) }
+                }
             }
         }
     }
@@ -152,6 +177,7 @@ class Coroutine<T>(
         value: R,
         callback: Callback<R>
     ) {
+        if (!scope.isActive) return
         if (null == callback.context) {
             callback.block.invoke(scope, value)
         } else {
diff --git a/app/src/main/java/io/legado/app/help/storage/Backup.kt b/app/src/main/java/io/legado/app/help/storage/Backup.kt
index 8c4fa8fc2..32bc2b765 100644
--- a/app/src/main/java/io/legado/app/help/storage/Backup.kt
+++ b/app/src/main/java/io/legado/app/help/storage/Backup.kt
@@ -54,35 +54,37 @@ object Backup {
     suspend fun backup(context: Context, path: String = legadoPath) {
         context.putPrefLong(PreferKey.lastBackup, System.currentTimeMillis())
         withContext(IO) {
-            writeListToJson(App.db.bookDao().all, "bookshelf.json", backupPath)
-            writeListToJson(App.db.bookGroupDao().all, "bookGroup.json", backupPath)
-            writeListToJson(App.db.bookSourceDao().all, "bookSource.json", backupPath)
-            writeListToJson(App.db.rssSourceDao().all, "rssSource.json", backupPath)
-            writeListToJson(App.db.rssStarDao().all, "rssStar.json", backupPath)
-            writeListToJson(App.db.replaceRuleDao().all, "replaceRule.json", backupPath)
-            GSON.toJson(ReadBookConfig.configList)?.let {
-                FileUtils.createFileIfNotExist(backupPath + File.separator + ReadBookConfig.readConfigFileName)
-                    .writeText(it)
-            }
-            Preferences.getSharedPreferences(App.INSTANCE, backupPath, "config")?.let { sp ->
-                val edit = sp.edit()
-                App.INSTANCE.defaultSharedPreferences.all.map {
-                    when (val value = it.value) {
-                        is Int -> edit.putInt(it.key, value)
-                        is Boolean -> edit.putBoolean(it.key, value)
-                        is Long -> edit.putLong(it.key, value)
-                        is Float -> edit.putFloat(it.key, value)
-                        is String -> edit.putString(it.key, value)
-                        else -> Unit
+            synchronized(this@Backup) {
+                writeListToJson(App.db.bookDao().all, "bookshelf.json", backupPath)
+                writeListToJson(App.db.bookGroupDao().all, "bookGroup.json", backupPath)
+                writeListToJson(App.db.bookSourceDao().all, "bookSource.json", backupPath)
+                writeListToJson(App.db.rssSourceDao().all, "rssSource.json", backupPath)
+                writeListToJson(App.db.rssStarDao().all, "rssStar.json", backupPath)
+                writeListToJson(App.db.replaceRuleDao().all, "replaceRule.json", backupPath)
+                GSON.toJson(ReadBookConfig.configList)?.let {
+                    FileUtils.createFileIfNotExist(backupPath + File.separator + ReadBookConfig.readConfigFileName)
+                        .writeText(it)
+                }
+                Preferences.getSharedPreferences(App.INSTANCE, backupPath, "config")?.let { sp ->
+                    val edit = sp.edit()
+                    App.INSTANCE.defaultSharedPreferences.all.map {
+                        when (val value = it.value) {
+                            is Int -> edit.putInt(it.key, value)
+                            is Boolean -> edit.putBoolean(it.key, value)
+                            is Long -> edit.putLong(it.key, value)
+                            is Float -> edit.putFloat(it.key, value)
+                            is String -> edit.putString(it.key, value)
+                            else -> Unit
+                        }
                     }
+                    edit.commit()
+                }
+                WebDavHelp.backUpWebDav(backupPath)
+                if (path.isContentPath()) {
+                    copyBackup(context, Uri.parse(path))
+                } else {
+                    copyBackup(File(path))
                 }
-                edit.commit()
-            }
-            WebDavHelp.backUpWebDav(backupPath)
-            if (path.isContentPath()) {
-                copyBackup(context, Uri.parse(path))
-            } else {
-                copyBackup(File(path))
             }
         }
     }
@@ -96,6 +98,7 @@ object Backup {
 
     @Throws(java.lang.Exception::class)
     private fun copyBackup(context: Context, uri: Uri) {
+
         DocumentFile.fromTreeUri(context, uri)?.let { treeDoc ->
             for (fileName in backupFileNames) {
                 val file = File(backupPath + File.separator + fileName)
diff --git a/app/src/main/java/io/legado/app/help/storage/OldBook.kt b/app/src/main/java/io/legado/app/help/storage/OldBook.kt
index f8321973c..a782cf5f5 100644
--- a/app/src/main/java/io/legado/app/help/storage/OldBook.kt
+++ b/app/src/main/java/io/legado/app/help/storage/OldBook.kt
@@ -40,7 +40,6 @@ object OldBook {
             book.durChapterTitle = jsonItem.readString("$.durChapterName")
             book.durChapterPos = jsonItem.readInt("$.durChapterPage") ?: 0
             book.durChapterTime = jsonItem.readLong("$.finalDate") ?: 0
-            book.group = jsonItem.readInt("$.group") ?: 0
             book.intro = jsonItem.readString("$.bookInfoBean.introduce")
             book.latestChapterTitle = jsonItem.readString("$.lastChapterName")
             book.lastCheckCount = jsonItem.readInt("$.newChapters") ?: 0
diff --git a/app/src/main/java/io/legado/app/model/SearchBook.kt b/app/src/main/java/io/legado/app/model/SearchBook.kt
new file mode 100644
index 000000000..7b344e60f
--- /dev/null
+++ b/app/src/main/java/io/legado/app/model/SearchBook.kt
@@ -0,0 +1,5 @@
+package io.legado.app.model
+
+class SearchBook {
+
+}
\ No newline at end of file
diff --git a/app/src/main/java/io/legado/app/model/WebBook.kt b/app/src/main/java/io/legado/app/model/WebBook.kt
index 7d14ea8bc..6fee7add6 100644
--- a/app/src/main/java/io/legado/app/model/WebBook.kt
+++ b/app/src/main/java/io/legado/app/model/WebBook.kt
@@ -29,11 +29,12 @@ class WebBook(val bookSource: BookSource) {
         context: CoroutineContext = Dispatchers.IO
     ): Coroutine<List<SearchBook>> {
         return Coroutine.async(scope, context) {
-            searchBookSuspend(key, page)
+            searchBookSuspend(scope, key, page)
         }
     }
 
     suspend fun searchBookSuspend(
+        scope: CoroutineScope,
         key: String,
         page: Int? = 1
     ): ArrayList<SearchBook> {
@@ -47,6 +48,7 @@ class WebBook(val bookSource: BookSource) {
             )
             val res = analyzeUrl.getResponseAwait(bookSource.bookSourceUrl)
             return BookList.analyzeBookList(
+                scope,
                 res.body,
                 bookSource,
                 analyzeUrl,
@@ -75,6 +77,7 @@ class WebBook(val bookSource: BookSource) {
             )
             val res = analyzeUrl.getResponseAwait(bookSource.bookSourceUrl)
             BookList.analyzeBookList(
+                scope,
                 res.body,
                 bookSource,
                 analyzeUrl,
diff --git a/app/src/main/java/io/legado/app/model/webBook/BookList.kt b/app/src/main/java/io/legado/app/model/webBook/BookList.kt
index a205c950a..372a4eec6 100644
--- a/app/src/main/java/io/legado/app/model/webBook/BookList.kt
+++ b/app/src/main/java/io/legado/app/model/webBook/BookList.kt
@@ -9,11 +9,15 @@ import io.legado.app.model.Debug
 import io.legado.app.model.analyzeRule.AnalyzeRule
 import io.legado.app.model.analyzeRule.AnalyzeUrl
 import io.legado.app.utils.NetworkUtils
+import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.isActive
 
 object BookList {
 
     @Throws(Exception::class)
     fun analyzeBookList(
+        scope: CoroutineScope,
         body: String?,
         bookSource: BookSource,
         analyzeUrl: AnalyzeUrl,
@@ -28,12 +32,13 @@ object BookList {
             )
         )
         Debug.log(bookSource.bookSourceUrl, "≡获取成功:${analyzeUrl.ruleUrl}")
+        if (!scope.isActive) throw CancellationException()
         val analyzeRule = AnalyzeRule(null)
         analyzeRule.setContent(body, baseUrl)
         bookSource.bookUrlPattern?.let {
             if (baseUrl.matches(it.toRegex())) {
                 Debug.log(bookSource.bookSourceUrl, "≡链接为详情页")
-                getInfoItem(analyzeRule, bookSource, baseUrl)?.let { searchBook ->
+                getInfoItem(scope, analyzeRule, bookSource, baseUrl)?.let { searchBook ->
                     searchBook.infoHtml = body
                     bookList.add(searchBook)
                 }
@@ -59,7 +64,7 @@ object BookList {
         collections = analyzeRule.getElements(ruleList)
         if (collections.isEmpty() && bookSource.bookUrlPattern.isNullOrEmpty()) {
             Debug.log(bookSource.bookSourceUrl, "└列表为空,按详情页解析")
-            getInfoItem(analyzeRule, bookSource, baseUrl)?.let { searchBook ->
+            getInfoItem(scope, analyzeRule, bookSource, baseUrl)?.let { searchBook ->
                 searchBook.infoHtml = body
                 bookList.add(searchBook)
             }
@@ -74,8 +79,9 @@ object BookList {
             val ruleWordCount = analyzeRule.splitSourceRule(bookListRule.wordCount)
             Debug.log(bookSource.bookSourceUrl, "└列表大小:${collections.size}")
             for ((index, item) in collections.withIndex()) {
+                if (!scope.isActive) throw CancellationException()
                 getSearchItem(
-                    item, analyzeRule, bookSource, baseUrl, index == 0,
+                    scope, item, analyzeRule, bookSource, baseUrl, index == 0,
                     ruleName = ruleName, ruleBookUrl = ruleBookUrl, ruleAuthor = ruleAuthor,
                     ruleCoverUrl = ruleCoverUrl, ruleIntro = ruleIntro, ruleKind = ruleKind,
                     ruleLastChapter = ruleLastChapter, ruleWordCount = ruleWordCount
@@ -93,7 +99,9 @@ object BookList {
         return bookList
     }
 
+    @Throws(Exception::class)
     private fun getInfoItem(
+        scope: CoroutineScope,
         analyzeRule: AnalyzeRule,
         bookSource: BookSource,
         baseUrl: String
@@ -108,29 +116,37 @@ object BookList {
         with(bookSource.getBookInfoRule()) {
             init?.let {
                 if (it.isNotEmpty()) {
+                    if (!scope.isActive) throw CancellationException()
                     Debug.log(bookSource.bookSourceUrl, "≡执行详情页初始化规则")
                     analyzeRule.setContent(analyzeRule.getElement(it))
                 }
             }
+            if (!scope.isActive) throw CancellationException()
             Debug.log(bookSource.bookSourceUrl, "┌获取书名")
             searchBook.name = analyzeRule.getString(name)
             Debug.log(bookSource.bookSourceUrl, "└${searchBook.name}")
             if (searchBook.name.isNotEmpty()) {
+                if (!scope.isActive) throw CancellationException()
                 Debug.log(bookSource.bookSourceUrl, "┌获取作者")
                 searchBook.author = BookHelp.formatAuthor(analyzeRule.getString(author))
                 Debug.log(bookSource.bookSourceUrl, "└${searchBook.author}")
+                if (!scope.isActive) throw CancellationException()
                 Debug.log(bookSource.bookSourceUrl, "┌获取分类")
                 searchBook.kind = analyzeRule.getStringList(kind)?.joinToString(",")
                 Debug.log(bookSource.bookSourceUrl, "└${searchBook.kind}")
+                if (!scope.isActive) throw CancellationException()
                 Debug.log(bookSource.bookSourceUrl, "┌获取字数")
                 searchBook.wordCount = analyzeRule.getString(wordCount)
                 Debug.log(bookSource.bookSourceUrl, "└${searchBook.wordCount}")
+                if (!scope.isActive) throw CancellationException()
                 Debug.log(bookSource.bookSourceUrl, "┌获取最新章节")
                 searchBook.latestChapterTitle = analyzeRule.getString(lastChapter)
                 Debug.log(bookSource.bookSourceUrl, "└${searchBook.latestChapterTitle}")
+                if (!scope.isActive) throw CancellationException()
                 Debug.log(bookSource.bookSourceUrl, "┌获取简介")
                 searchBook.intro = analyzeRule.getString(intro)
                 Debug.log(bookSource.bookSourceUrl, "└${searchBook.intro}", true)
+                if (!scope.isActive) throw CancellationException()
                 Debug.log(bookSource.bookSourceUrl, "┌获取封面链接")
                 searchBook.coverUrl = analyzeRule.getString(coverUrl, true)
                 Debug.log(bookSource.bookSourceUrl, "└${searchBook.coverUrl}")
@@ -140,7 +156,9 @@ object BookList {
         return null
     }
 
+    @Throws(Exception::class)
     private fun getSearchItem(
+        scope: CoroutineScope,
         item: Any,
         analyzeRule: AnalyzeRule,
         bookSource: BookSource,
@@ -162,30 +180,38 @@ object BookList {
         searchBook.originOrder = bookSource.customOrder
         analyzeRule.book = searchBook
         analyzeRule.setContent(item)
+        if (!scope.isActive) throw CancellationException()
         Debug.log(bookSource.bookSourceUrl, "┌获取书名", log)
         searchBook.name = analyzeRule.getString(ruleName)
         Debug.log(bookSource.bookSourceUrl, "└${searchBook.name}", log)
         if (searchBook.name.isNotEmpty()) {
+            if (!scope.isActive) throw CancellationException()
             Debug.log(bookSource.bookSourceUrl, "┌获取作者", log)
             searchBook.author = BookHelp.formatAuthor(analyzeRule.getString(ruleAuthor))
             Debug.log(bookSource.bookSourceUrl, "└${searchBook.author}", log)
+            if (!scope.isActive) throw CancellationException()
             Debug.log(bookSource.bookSourceUrl, "┌获取分类", log)
             searchBook.kind = analyzeRule.getStringList(ruleKind)?.joinToString(",")
             Debug.log(bookSource.bookSourceUrl, "└${searchBook.kind}", log)
+            if (!scope.isActive) throw CancellationException()
             Debug.log(bookSource.bookSourceUrl, "┌获取字数", log)
             searchBook.wordCount = analyzeRule.getString(ruleWordCount)
             Debug.log(bookSource.bookSourceUrl, "└${searchBook.wordCount}", log)
+            if (!scope.isActive) throw CancellationException()
             Debug.log(bookSource.bookSourceUrl, "┌获取最新章节", log)
             searchBook.latestChapterTitle = analyzeRule.getString(ruleLastChapter)
             Debug.log(bookSource.bookSourceUrl, "└${searchBook.latestChapterTitle}", log)
+            if (!scope.isActive) throw CancellationException()
             Debug.log(bookSource.bookSourceUrl, "┌获取简介", log)
             searchBook.intro = analyzeRule.getString(ruleIntro)
             Debug.log(bookSource.bookSourceUrl, "└${searchBook.intro}", log, true)
+            if (!scope.isActive) throw CancellationException()
             Debug.log(bookSource.bookSourceUrl, "┌获取封面链接", log)
             analyzeRule.getString(ruleCoverUrl).let {
                 if (it.isNotEmpty()) searchBook.coverUrl = NetworkUtils.getAbsoluteURL(baseUrl, it)
             }
             Debug.log(bookSource.bookSourceUrl, "└${searchBook.coverUrl}", log)
+            if (!scope.isActive) throw CancellationException()
             Debug.log(bookSource.bookSourceUrl, "┌获取详情页链接", log)
             searchBook.bookUrl = analyzeRule.getString(ruleBookUrl, true)
             if (searchBook.bookUrl.isEmpty()) {
diff --git a/app/src/main/java/io/legado/app/ui/book/changecover/ChangeCoverViewModel.kt b/app/src/main/java/io/legado/app/ui/book/changecover/ChangeCoverViewModel.kt
index 627bacc09..bcd0e61d0 100644
--- a/app/src/main/java/io/legado/app/ui/book/changecover/ChangeCoverViewModel.kt
+++ b/app/src/main/java/io/legado/app/ui/book/changecover/ChangeCoverViewModel.kt
@@ -51,7 +51,6 @@ class ChangeCoverViewModel(application: Application) : BaseViewModel(application
 
     fun search() {
         task = execute {
-            searchStateData.postValue(true)
             val bookSourceList = App.db.bookSourceDao().allEnabled
             for (item in bookSourceList) {
                 //task取消时自动取消 by （scope = this@execute）
@@ -72,6 +71,10 @@ class ChangeCoverViewModel(application: Application) : BaseViewModel(application
                         }
                     }
             }
+        }.onStart {
+            searchStateData.postValue(true)
+        }.onCancel {
+            searchStateData.postValue(false)
         }
 
         task?.invokeOnCompletion {
diff --git a/app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceViewModel.kt b/app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceViewModel.kt
index e0800c0a1..5b1c7e939 100644
--- a/app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceViewModel.kt
+++ b/app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceViewModel.kt
@@ -72,7 +72,6 @@ class ChangeSourceViewModel(application: Application) : BaseViewModel(applicatio
 
     fun search() {
         task = execute {
-            searchStateData.postValue(true)
             val bookSourceList = App.db.bookSourceDao().allEnabled
             for (item in bookSourceList) {
                 //task取消时自动取消 by （scope = this@execute）
@@ -95,6 +94,10 @@ class ChangeSourceViewModel(application: Application) : BaseViewModel(applicatio
                         }
                     }
             }
+        }.onStart {
+            searchStateData.postValue(true)
+        }.onCancel {
+            searchStateData.postValue(false)
         }
 
         task?.invokeOnCompletion {
diff --git a/app/src/main/java/io/legado/app/ui/book/read/ReadBookViewModel.kt b/app/src/main/java/io/legado/app/ui/book/read/ReadBookViewModel.kt
index 25d94bdea..2994dcac2 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/ReadBookViewModel.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/ReadBookViewModel.kt
@@ -161,7 +161,7 @@ class ReadBookViewModel(application: Application) : BaseViewModel(application) {
         execute {
             App.db.bookSourceDao().allTextEnabled.forEach { source ->
                 try {
-                    val searchBooks = WebBook(source).searchBookSuspend(name)
+                    val searchBooks = WebBook(source).searchBookSuspend(this, name)
                     searchBooks.getOrNull(0)?.let {
                         if (it.name == name && (it.author == author || author == "")) {
                             changeTo(it.toBook())
diff --git a/app/src/main/java/io/legado/app/ui/book/search/DiffCallBack.kt b/app/src/main/java/io/legado/app/ui/book/search/DiffCallBack.kt
index d0c2f2973..999f2a941 100644
--- a/app/src/main/java/io/legado/app/ui/book/search/DiffCallBack.kt
+++ b/app/src/main/java/io/legado/app/ui/book/search/DiffCallBack.kt
@@ -50,8 +50,8 @@ class DiffCallBack(private val oldItems: List<SearchBook>, private val newItems:
 
     override fun getChangePayload(oldItemPosition: Int, newItemPosition: Int): Any? {
         val payload = Bundle()
-        val newItem: SearchBook? = if ((newItemPosition >= 0) && (newItemPosition < newItems.size)) newItems[newItemPosition] else null
-        val oldItem: SearchBook? = if ((oldItemPosition >= 0) && (oldItemPosition < oldItems.size)) oldItems[oldItemPosition] else null
+        val newItem = newItems.getOrNull(newItemPosition)
+        val oldItem = oldItems.getOrNull(oldItemPosition)
         if (newItem == null) return payload
         if (oldItem?.name != newItem.name) {
             payload.putString("name", newItem.name)
diff --git a/app/src/main/java/io/legado/app/ui/book/search/SearchActivity.kt b/app/src/main/java/io/legado/app/ui/book/search/SearchActivity.kt
index 4373dd41a..e81545adc 100644
--- a/app/src/main/java/io/legado/app/ui/book/search/SearchActivity.kt
+++ b/app/src/main/java/io/legado/app/ui/book/search/SearchActivity.kt
@@ -3,7 +3,6 @@ package io.legado.app.ui.book.search
 import android.os.Bundle
 import android.view.Menu
 import android.view.MenuItem
-import android.view.View
 import android.view.View.GONE
 import android.view.View.VISIBLE
 import androidx.appcompat.widget.SearchView
@@ -113,6 +112,7 @@ class SearchActivity : VMBaseActivity<SearchViewModel>(R.layout.activity_book_se
                     viewModel.saveSearchKey(query)
                     viewModel.search(it)
                 }
+                openOrCloseHistory(false)
                 return true
             }
 
diff --git a/app/src/main/java/io/legado/app/ui/book/search/SearchViewModel.kt b/app/src/main/java/io/legado/app/ui/book/search/SearchViewModel.kt
index 47671626d..f1a4fc858 100644
--- a/app/src/main/java/io/legado/app/ui/book/search/SearchViewModel.kt
+++ b/app/src/main/java/io/legado/app/ui/book/search/SearchViewModel.kt
@@ -12,8 +12,10 @@ import io.legado.app.help.coroutine.Coroutine
 import io.legado.app.model.WebBook
 import io.legado.app.utils.getPrefBoolean
 import io.legado.app.utils.getPrefString
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.coroutines.asCoroutineDispatcher
+import kotlinx.coroutines.isActive
 import java.util.concurrent.Executors
 
 class SearchViewModel(application: Application) : BaseViewModel(application) {
@@ -43,7 +45,6 @@ class SearchViewModel(application: Application) : BaseViewModel(application) {
             searchKey = key
             searchBooks.clear()
         }
-        isSearchLiveData.postValue(true)
         task = execute {
             val searchGroup = context.getPrefString("searchGroup") ?: ""
             val bookSourceList = if (searchGroup.isBlank()) {
@@ -54,23 +55,30 @@ class SearchViewModel(application: Application) : BaseViewModel(application) {
             for (item in bookSourceList) {
                 //task取消时自动取消 by （scope = this@execute）
                 WebBook(item).searchBook(
-                    searchKey,
-                    searchPage,
-                    scope = this@execute,
-                    context = searchPool
-                )
+                        searchKey,
+                        searchPage,
+                        scope = this,
+                        context = searchPool
+                    )
                     .timeout(30000L)
                     .onSuccess(IO) {
-                        it?.let { list ->
-                            if (context.getPrefBoolean(PreferKey.precisionSearch)) {
-                                precisionSearch(list)
-                            } else {
-                                App.db.searchBookDao().insert(*list.toTypedArray())
-                                mergeItems(list)
+                        if (isActive) {
+                            it?.let { list ->
+                                if (context.getPrefBoolean(PreferKey.precisionSearch)) {
+                                    precisionSearch(this, list)
+                                } else {
+                                    App.db.searchBookDao().insert(*list.toTypedArray())
+                                    mergeItems(this, list)
+                                }
                             }
                         }
                     }
             }
+        }.onStart {
+            isSearchLiveData.postValue(true)
+        }.onCancel {
+            isSearchLiveData.postValue(false)
+            isLoading = false
         }
 
         task?.invokeOnCompletion {
@@ -82,7 +90,7 @@ class SearchViewModel(application: Application) : BaseViewModel(application) {
     /**
      * 精确搜索处理
      */
-    private fun precisionSearch(searchBooks: List<SearchBook>) {
+    private fun precisionSearch(scope: CoroutineScope, searchBooks: List<SearchBook>) {
         val books = arrayListOf<SearchBook>()
         searchBooks.forEach { searchBook ->
             if (searchBook.name.contains(searchKey, true)
@@ -90,14 +98,16 @@ class SearchViewModel(application: Application) : BaseViewModel(application) {
             ) books.add(searchBook)
         }
         App.db.searchBookDao().insert(*books.toTypedArray())
-        mergeItems(books)
+        if (scope.isActive) {
+            mergeItems(scope, books)
+        }
     }
 
     /**
      * 合并搜索结果并排序
      */
     @Synchronized
-    private fun mergeItems(newDataS: List<SearchBook>) {
+    private fun mergeItems(scope: CoroutineScope, newDataS: List<SearchBook>) {
         if (newDataS.isNotEmpty()) {
             val copyDataS = ArrayList(searchBooks)
             val searchBooksAdd = ArrayList<SearchBook>()
@@ -141,6 +151,7 @@ class SearchViewModel(application: Application) : BaseViewModel(application) {
                     }
                 }
             }
+            if (!scope.isActive) return
             searchBooks.sortWith(Comparator { o1, o2 ->
                 if (o1.name == searchKey && o2.name != searchKey) {
                     1
@@ -166,6 +177,7 @@ class SearchViewModel(application: Application) : BaseViewModel(application) {
                     0
                 }
             })
+            if (!scope.isActive) return
             searchBooks = copyDataS
             searchBookLiveData.postValue(copyDataS)
         }
diff --git a/app/src/main/java/io/legado/app/ui/main/explore/ExploreAdapter.kt b/app/src/main/java/io/legado/app/ui/main/explore/ExploreAdapter.kt
index faf9cef8a..ccfa5bf82 100644
--- a/app/src/main/java/io/legado/app/ui/main/explore/ExploreAdapter.kt
+++ b/app/src/main/java/io/legado/app/ui/main/explore/ExploreAdapter.kt
@@ -24,7 +24,7 @@ import org.jetbrains.anko.sdk27.listeners.onLongClick
 
 class ExploreAdapter(context: Context, private val scope: CoroutineScope, val callBack: CallBack) :
     SimpleRecyclerAdapter<BookSource>(context, R.layout.item_find_book) {
-    private var exIndex = 0
+    private var exIndex = -1
     private var scrollTo = -1
 
     override fun convert(holder: ItemViewHolder, item: BookSource, payloads: MutableList<Any>) {
diff --git a/app/src/main/java/io/legado/app/ui/rss/read/VisibleWebView.kt b/app/src/main/java/io/legado/app/ui/rss/read/VisibleWebView.kt
new file mode 100644
index 000000000..0e6e1b40b
--- /dev/null
+++ b/app/src/main/java/io/legado/app/ui/rss/read/VisibleWebView.kt
@@ -0,0 +1,17 @@
+package io.legado.app.ui.rss.read
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.View
+import android.webkit.WebView
+
+class VisibleWebView(
+    context: Context,
+    attrs: AttributeSet? = null
+) : WebView(context, attrs) {
+
+    override fun onWindowVisibilityChanged(visibility: Int) {
+        super.onWindowVisibilityChanged(View.VISIBLE)
+    }
+
+}
\ No newline at end of file
diff --git a/app/src/main/java/io/legado/app/ui/widget/SearchView.kt b/app/src/main/java/io/legado/app/ui/widget/SearchView.kt
index a1d8bd5f6..765a0a580 100644
--- a/app/src/main/java/io/legado/app/ui/widget/SearchView.kt
+++ b/app/src/main/java/io/legado/app/ui/widget/SearchView.kt
@@ -11,7 +11,6 @@ import android.text.style.ImageSpan
 import android.util.AttributeSet
 import android.util.TypedValue
 import android.view.Gravity
-import android.view.View
 import android.widget.TextView
 import androidx.appcompat.widget.SearchView
 import io.legado.app.R
@@ -41,8 +40,7 @@ class SearchView : SearchView {
         super.onLayout(changed, left, top, right, bottom)
         try {
             if (textView == null) {
-                textView =
-                    findViewById<View>(androidx.appcompat.R.id.search_src_text) as TextView
+                textView = findViewById(androidx.appcompat.R.id.search_src_text)
                 mSearchHintIcon = this.context.getDrawable(R.drawable.ic_search_hint)
                 updateQueryHint()
             }
@@ -69,9 +67,8 @@ class SearchView : SearchView {
     }
 
     private fun updateQueryHint() {
-        if (textView != null) {
-            val hint = queryHint
-            textView!!.hint = getDecoratedHint(hint ?: "")
+        textView?.let {
+            it.hint = getDecoratedHint(queryHint ?: "")
         }
     }
 
@@ -91,23 +88,23 @@ class SearchView : SearchView {
         super.setQueryHint(hint)
         updateQueryHint()
     }
-}
 
-internal class CenteredImageSpan(drawable: Drawable?) : ImageSpan(drawable!!) {
-    override fun draw(
-        canvas: Canvas, text: CharSequence,
-        start: Int, end: Int, x: Float,
-        top: Int, y: Int, bottom: Int, paint: Paint
-    ) {
-        // image to draw
-        val b = drawable
-        // font metrics of text to be replaced
-        val fm = paint.fontMetricsInt
-        val transY = ((y + fm.descent + y + fm.ascent) / 2
-                - b.bounds.bottom / 2)
-        canvas.save()
-        canvas.translate(x, transY.toFloat())
-        b.draw(canvas)
-        canvas.restore()
+    internal class CenteredImageSpan(drawable: Drawable?) : ImageSpan(drawable!!) {
+        override fun draw(
+            canvas: Canvas, text: CharSequence,
+            start: Int, end: Int, x: Float,
+            top: Int, y: Int, bottom: Int, paint: Paint
+        ) {
+            // image to draw
+            val b = drawable
+            // font metrics of text to be replaced
+            val fm = paint.fontMetricsInt
+            val transY = ((y + fm.descent + y + fm.ascent) / 2
+                    - b.bounds.bottom / 2)
+            canvas.save()
+            canvas.translate(x, transY.toFloat())
+            b.draw(canvas)
+            canvas.restore()
+        }
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/res/layout/activity_rss_read.xml b/app/src/main/res/layout/activity_rss_read.xml
index 76f630002..ea4131764 100644
--- a/app/src/main/res/layout/activity_rss_read.xml
+++ b/app/src/main/res/layout/activity_rss_read.xml
@@ -15,7 +15,7 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content" />
 
-        <WebView
+        <io.legado.app.ui.rss.read.VisibleWebView
             android:id="@+id/web_view"
             android:layout_width="match_parent"
             android:layout_height="match_parent" />
diff --git a/app/src/main/res/layout/view_search.xml b/app/src/main/res/layout/view_search.xml
index b1809c534..96ff311da 100644
--- a/app/src/main/res/layout/view_search.xml
+++ b/app/src/main/res/layout/view_search.xml
@@ -14,5 +14,4 @@
         app:queryBackground="@null"
         app:submitBackground="@null"
         app:searchHintIcon="@drawable/ic_search_hint"
-        app:goIcon="@drawable/ic_search"
         app:defaultQueryHint="搜索"/>
\ No newline at end of file