diff --git a/app/src/main/java/io/legado/app/base/BaseViewModel.kt b/app/src/main/java/io/legado/app/base/BaseViewModel.kt
index 03b17ad49..c647b34bd 100644
--- a/app/src/main/java/io/legado/app/base/BaseViewModel.kt
+++ b/app/src/main/java/io/legado/app/base/BaseViewModel.kt
@@ -10,13 +10,12 @@ open class BaseViewModel(application: Application) : AndroidViewModel(applicatio
     override val coroutineContext: CoroutineContext
         get() = Dispatchers.Main
 
-
     private val launchManager: MutableList<Job> = mutableListOf()
 
     protected fun launchOnUI(
-        tryBlock: suspend CoroutineScope.() -> Unit,//成功
-        errorBlock: suspend CoroutineScope.(Throwable) -> Unit,//失败
-        finallyBlock: suspend CoroutineScope.() -> Unit//结束
+        tryBlock: suspend CoroutineScope.() -> Unit,
+        errorBlock: (suspend CoroutineScope.(Throwable) -> Unit)? = null,//失败
+        finallyBlock: (suspend CoroutineScope.() -> Unit)? = null//结束
     ) {
         launchOnUI {
             tryCatch(tryBlock, errorBlock, finallyBlock)
@@ -34,15 +33,15 @@ open class BaseViewModel(application: Application) : AndroidViewModel(applicatio
 
     private suspend fun tryCatch(
         tryBlock: suspend CoroutineScope.() -> Unit,
-        errorBlock: suspend CoroutineScope.(Throwable) -> Unit,
-        finallyBlock: suspend CoroutineScope.() -> Unit
+        errorBlock: (suspend CoroutineScope.(Throwable) -> Unit)? = null,
+        finallyBlock: (suspend CoroutineScope.() -> Unit)? = null
     ) {
         try {
             coroutineScope { tryBlock() }
         } catch (e: Throwable) {
-            coroutineScope { errorBlock(e) }
+            coroutineScope { errorBlock?.let { it(e) } }
         } finally {
-            coroutineScope { finallyBlock() }
+            coroutineScope { finallyBlock?.let { it() } }
         }
     }
 
diff --git a/app/src/main/java/io/legado/app/ui/main/MainViewModel.kt b/app/src/main/java/io/legado/app/ui/main/MainViewModel.kt
index 82a9146c5..cf2f8f600 100644
--- a/app/src/main/java/io/legado/app/ui/main/MainViewModel.kt
+++ b/app/src/main/java/io/legado/app/ui/main/MainViewModel.kt
@@ -1,9 +1,22 @@
 package io.legado.app.ui.main
 
 import android.app.Application
-import androidx.lifecycle.AndroidViewModel
+import io.legado.app.App
+import io.legado.app.base.BaseViewModel
+import kotlinx.coroutines.async
+import org.jetbrains.anko.toast
 
-class MainViewModel(application: Application) : AndroidViewModel(application) {
+class MainViewModel(application: Application) : BaseViewModel(application) {
 
+    fun test() {
+        launchOnUI({
+
+            val result = async {
+                "结果"
+            }
+
+//            App.INSTANCE.toast("result: $result")
+        })
+    }
 
 }
\ No newline at end of file
diff --git a/app/src/main/java/io/legado/app/ui/search/SearchViewModel.kt b/app/src/main/java/io/legado/app/ui/search/SearchViewModel.kt
index 4f7bc17c7..594672d74 100644
--- a/app/src/main/java/io/legado/app/ui/search/SearchViewModel.kt
+++ b/app/src/main/java/io/legado/app/ui/search/SearchViewModel.kt
@@ -1,7 +1,6 @@
 package io.legado.app.ui.search
 
 import android.app.Application
-import android.util.Log
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import io.legado.app.base.BaseViewModel
@@ -10,12 +9,13 @@ import io.legado.app.data.entities.SearchBook
 import io.legado.app.help.http.HttpHelper
 import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.coroutines.withContext
+import org.jetbrains.anko.error
 
 class SearchViewModel(application: Application) : BaseViewModel(application) {
 
     val searchBooks: LiveData<List<SearchBook>> = MutableLiveData()
 
-    public fun search(start: () -> Unit, finally: () -> Unit) {
+    fun search(start: () -> Unit, finally: () -> Unit) {
         launchOnUI(
             {
                 start()
@@ -27,12 +27,8 @@ class SearchViewModel(application: Application) : BaseViewModel(application) {
 
                 val result = searchResponse.await()
             },
-            { Log.i("TAG", "${it.message}") },
+            { error { "${it.message}" } },
             { finally() })
-
-//        GlobalScope.launch {
-//
-//        }
     }
 
 }
diff --git a/app/src/main/java/io/legado/app/ui/sourceedit/SourceEditViewModel.kt b/app/src/main/java/io/legado/app/ui/sourceedit/SourceEditViewModel.kt
index b1af68e88..950eeb0bd 100644
--- a/app/src/main/java/io/legado/app/ui/sourceedit/SourceEditViewModel.kt
+++ b/app/src/main/java/io/legado/app/ui/sourceedit/SourceEditViewModel.kt
@@ -1,19 +1,19 @@
 package io.legado.app.ui.sourceedit
 
 import android.app.Application
-import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.MutableLiveData
 import io.legado.app.App
+import io.legado.app.base.BaseViewModel
 import io.legado.app.data.entities.BookSource
-import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 
-class SourceEditViewModel(application: Application) : AndroidViewModel(application) {
+class SourceEditViewModel(application: Application) : BaseViewModel(application) {
 
     val sourceLiveData: MutableLiveData<BookSource> = MutableLiveData()
 
     fun setBookSource(key: String) {
-        GlobalScope.launch {
+        launch(Dispatchers.IO) {
             val source = App.db.bookSourceDao().findByKey(key)
             sourceLiveData.postValue(source)
         }