diff --git a/app/src/main/java/io/legado/app/service/AudioPlayService.kt b/app/src/main/java/io/legado/app/service/AudioPlayService.kt
index 1817da185..d629f2ba8 100644
--- a/app/src/main/java/io/legado/app/service/AudioPlayService.kt
+++ b/app/src/main/java/io/legado/app/service/AudioPlayService.kt
@@ -12,6 +12,7 @@ import android.media.MediaPlayer
 import android.net.Uri
 import android.os.Build
 import android.os.Handler
+import android.os.Looper
 import android.support.v4.media.session.MediaSessionCompat
 import android.support.v4.media.session.PlaybackStateCompat
 import androidx.core.app.NotificationCompat
@@ -50,7 +51,7 @@ class AudioPlayService : BaseService(),
         var timeMinute: Int = 0
     }
 
-    private val handler = Handler()
+    private val handler = Handler(Looper.getMainLooper())
     private lateinit var audioManager: AudioManager
     private var mFocusRequest: AudioFocusRequest? = null
     private var title: String = ""
diff --git a/app/src/main/java/io/legado/app/service/BaseReadAloudService.kt b/app/src/main/java/io/legado/app/service/BaseReadAloudService.kt
index 2fd69506e..a51a7c3dd 100644
--- a/app/src/main/java/io/legado/app/service/BaseReadAloudService.kt
+++ b/app/src/main/java/io/legado/app/service/BaseReadAloudService.kt
@@ -9,6 +9,7 @@ import android.graphics.BitmapFactory
 import android.media.AudioFocusRequest
 import android.media.AudioManager
 import android.os.Handler
+import android.os.Looper
 import android.support.v4.media.session.MediaSessionCompat
 import android.support.v4.media.session.PlaybackStateCompat
 import androidx.annotation.CallSuper
@@ -40,7 +41,7 @@ abstract class BaseReadAloudService : BaseService(),
         }
     }
 
-    internal val handler = Handler()
+    internal val handler = Handler(Looper.getMainLooper())
     private lateinit var audioManager: AudioManager
     private var mFocusRequest: AudioFocusRequest? = null
     private var broadcastReceiver: BroadcastReceiver? = null
diff --git a/app/src/main/java/io/legado/app/service/CacheBookService.kt b/app/src/main/java/io/legado/app/service/CacheBookService.kt
index ed00be50e..0ef8a2ea2 100644
--- a/app/src/main/java/io/legado/app/service/CacheBookService.kt
+++ b/app/src/main/java/io/legado/app/service/CacheBookService.kt
@@ -2,6 +2,7 @@ package io.legado.app.service
 
 import android.content.Intent
 import android.os.Handler
+import android.os.Looper
 import androidx.core.app.NotificationCompat
 import io.legado.app.App
 import io.legado.app.R
@@ -32,7 +33,7 @@ class CacheBookService : BaseService() {
     private var searchPool =
         Executors.newFixedThreadPool(threadCount).asCoroutineDispatcher()
     private var tasks = CompositeCoroutine()
-    private val handler = Handler()
+    private val handler = Handler(Looper.getMainLooper())
     private var runnable: Runnable = Runnable { upDownload() }
     private val bookMap = ConcurrentHashMap<String, Book>()
     private val webBookMap = ConcurrentHashMap<String, WebBook>()
diff --git a/app/src/main/java/io/legado/app/service/DownloadService.kt b/app/src/main/java/io/legado/app/service/DownloadService.kt
index b9f4f82fe..fd21a079b 100644
--- a/app/src/main/java/io/legado/app/service/DownloadService.kt
+++ b/app/src/main/java/io/legado/app/service/DownloadService.kt
@@ -8,6 +8,7 @@ import android.content.IntentFilter
 import android.net.Uri
 import android.os.Build
 import android.os.Handler
+import android.os.Looper
 import androidx.core.app.NotificationCompat
 import androidx.core.content.FileProvider
 import androidx.core.os.bundleOf
@@ -28,7 +29,7 @@ class DownloadService : BaseService() {
 
     private val downloads = hashMapOf<Long, String>()
     private val completeDownloads = hashSetOf<Long>()
-    private val handler = Handler()
+    private val handler = Handler(Looper.getMainLooper())
     private val runnable = Runnable {
         checkDownloadState()
     }
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 0cbc1e2ee..979fbc8c7 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
@@ -3,6 +3,7 @@ package io.legado.app.ui.book.changesource
 import android.app.Application
 import android.os.Bundle
 import android.os.Handler
+import android.os.Looper
 import androidx.lifecycle.MutableLiveData
 import io.legado.app.App
 import io.legado.app.R
@@ -27,7 +28,7 @@ import kotlin.math.min
 class ChangeSourceViewModel(application: Application) : BaseViewModel(application) {
     private val threadCount = AppConfig.threadCount
     private var searchPool: ExecutorCoroutineDispatcher? = null
-    val handler = Handler()
+    val handler = Handler(Looper.getMainLooper())
     val searchStateData = MutableLiveData<Boolean>()
     val searchBooksLiveData = MutableLiveData<List<SearchBook>>()
     var name: String = ""
diff --git a/app/src/main/java/io/legado/app/ui/widget/text/BadgeView.kt b/app/src/main/java/io/legado/app/ui/widget/text/BadgeView.kt
index 353fa9de4..4f26a9ad2 100644
--- a/app/src/main/java/io/legado/app/ui/widget/text/BadgeView.kt
+++ b/app/src/main/java/io/legado/app/ui/widget/text/BadgeView.kt
@@ -12,7 +12,6 @@ import android.view.View
 import android.view.ViewGroup
 import android.widget.FrameLayout
 import android.widget.FrameLayout.LayoutParams
-import android.widget.TabWidget
 import androidx.appcompat.widget.AppCompatTextView
 import io.legado.app.R
 import io.legado.app.lib.theme.accentColor
@@ -186,16 +185,6 @@ class BadgeView @JvmOverloads constructor(
         incrementBadgeCount(-decrement)
     }
 
-    /**
-     * Attach the BadgeView to the TabWidget
-     * @param target the TabWidget to attach the BadgeView
-     * @param tabIndex index of the tab
-     */
-    fun setTargetView(target: TabWidget, tabIndex: Int) {
-        val tabView = target.getChildTabViewAt(tabIndex)
-        setTargetView(tabView)
-    }
-
     /**
      * Attach the BadgeView to the target view
      * @param target the view to attach the BadgeView