我使用ACRA报告应用程序崩溃。我得到了一个视图没有附加到窗口管理器错误消息,并认为我已经通过包装pDialog.dismiss()修复了它;在if语句中:
if (pDialog!=null)
{
if (pDialog.isShowing())
{
pDialog.dismiss();
}
}
它减少了我收到的未附加到窗口管理器崩溃的视图数量,但我仍然得到一些,我不确定如何解决它。
错误信息:
java.lang.IllegalArgumentException: View not attached to window manager
at android.view.WindowManagerGlobal.findViewLocked(WindowManagerGlobal.java:425)
at android.view.WindowManagerGlobal.removeView(WindowManagerGlobal.java:327)
at android.view.WindowManagerImpl.removeView(WindowManagerImpl.java:83)
at android.app.Dialog.dismissDialog(Dialog.java:330)
at android.app.Dialog.dismiss(Dialog.java:312)
at com.package.class$LoadAllProducts.onPostExecute(class.java:624)
at com.package.class$LoadAllProducts.onPostExecute(class.java:1)
at android.os.AsyncTask.finish(AsyncTask.java:631)
at android.os.AsyncTask.access$600(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:176)
at android.app.ActivityThread.main(ActivityThread.java:5419)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
at dalvik.system.NativeStart.main(Native Method)
代码片段:
class LoadAllProducts extends AsyncTask<String, String, String>
{
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute()
{
super.onPreExecute();
pDialog = new ProgressDialog(CLASS.this);
pDialog.setMessage("Loading. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args)
{
// Building Parameters
doMoreStuff("internet");
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url)
{
// dismiss the dialog after getting all products
if (pDialog!=null)
{
if (pDialog.isShowing())
{
pDialog.dismiss(); //This is line 624!
}
}
something(note);
}
}
清单:
<activity
android:name="pagename.CLASS"
android:configChanges="keyboard|keyboardHidden|orientation|screenSize|screenLayout"
android:label="@string/name" >
</activity>
为了阻止撞车,我错过了什么?
基于@erakitin的答案,但也兼容Android版本< API级别17。不幸的是,Activity.isDestroyed()只支持API级别17以后,所以如果你的目标是一个更老的API级别,就像我一样,你必须自己检查它。还没有得到视图没有附加到窗口管理器异常之后。
示例代码
public class MainActivity extends Activity {
private TestAsyncTask mAsyncTask;
private ProgressDialog mProgressDialog;
private boolean mIsDestroyed;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (condition) {
mAsyncTask = new TestAsyncTask();
mAsyncTask.execute();
}
}
@Override
protected void onResume() {
super.onResume();
if (mAsyncTask != null && mAsyncTask.getStatus() != AsyncTask.Status.FINISHED) {
Toast.makeText(this, "Still loading", Toast.LENGTH_LONG).show();
return;
}
}
@Override
protected void onDestroy() {
super.onDestroy();
mIsDestroyed = true;
if (mProgressDialog != null && mProgressDialog.isShowing()) {
mProgressDialog.dismiss();
}
}
public class TestAsyncTask extends AsyncTask<Void, Void, AsyncResult> {
@Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog = ProgressDialog.show(MainActivity.this, "Please wait", "doing stuff..");
}
@Override
protected AsyncResult doInBackground(Void... arg0) {
// Do long running background stuff
return null;
}
@Override
protected void onPostExecute(AsyncResult result) {
// Use MainActivity.this.isDestroyed() when targeting API level 17 or higher
if (mIsDestroyed)// Activity not there anymore
return;
mProgressDialog.dismiss();
// Handle rest onPostExecute
}
}
}
看看准则是如何运作的:
调用异步任务后,异步任务将在后台运行。这是可取的。现在,这个异步任务有一个附加到Activity的进度对话框,如果你问如何查看代码:
pDialog = new ProgressDialog(CLASS.this);
你通过考试了。这是论点的背景。因此Progress对话框仍然附加到活动。
现在考虑一下这个场景:
如果我们尝试使用finish()方法完成活动,当异步任务正在进行时,是您试图访问附加到活动的资源的点,即活动不再存在时的进度条。
因此你得到:
java.lang.IllegalArgumentException: View not attached to the window manager
解决方法:
1)确保对话框在活动结束前被解除或取消。
2)完成活动,只有在对话框被解散后,即异步任务结束。
基于@erakitin的答案,但也兼容Android版本< API级别17。不幸的是,Activity.isDestroyed()只支持API级别17以后,所以如果你的目标是一个更老的API级别,就像我一样,你必须自己检查它。还没有得到视图没有附加到窗口管理器异常之后。
示例代码
public class MainActivity extends Activity {
private TestAsyncTask mAsyncTask;
private ProgressDialog mProgressDialog;
private boolean mIsDestroyed;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (condition) {
mAsyncTask = new TestAsyncTask();
mAsyncTask.execute();
}
}
@Override
protected void onResume() {
super.onResume();
if (mAsyncTask != null && mAsyncTask.getStatus() != AsyncTask.Status.FINISHED) {
Toast.makeText(this, "Still loading", Toast.LENGTH_LONG).show();
return;
}
}
@Override
protected void onDestroy() {
super.onDestroy();
mIsDestroyed = true;
if (mProgressDialog != null && mProgressDialog.isShowing()) {
mProgressDialog.dismiss();
}
}
public class TestAsyncTask extends AsyncTask<Void, Void, AsyncResult> {
@Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog = ProgressDialog.show(MainActivity.this, "Please wait", "doing stuff..");
}
@Override
protected AsyncResult doInBackground(Void... arg0) {
// Do long running background stuff
return null;
}
@Override
protected void onPostExecute(AsyncResult result) {
// Use MainActivity.this.isDestroyed() when targeting API level 17 or higher
if (mIsDestroyed)// Activity not there anymore
return;
mProgressDialog.dismiss();
// Handle rest onPostExecute
}
}
}
我有办法重现这个异常。
我使用2 AsyncTask。一个人做长任务,另一个人做短任务。在短任务完成后,调用finish()。当长任务完成并调用Dialog.dismiss()时,它崩溃了。
下面是我的示例代码:
public class MainActivity extends Activity {
private static final String TAG = "MainActivity";
private ProgressDialog mProgressDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.d(TAG, "onCreate");
new AsyncTask<Void, Void, Void>(){
@Override
protected void onPreExecute() {
mProgressDialog = ProgressDialog.show(MainActivity.this, "", "plz wait...", true);
}
@Override
protected Void doInBackground(Void... nothing) {
try {
Log.d(TAG, "long thread doInBackground");
Thread.sleep(20000);
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
Log.d(TAG, "long thread onPostExecute");
if (mProgressDialog != null && mProgressDialog.isShowing()) {
mProgressDialog.dismiss();
mProgressDialog = null;
}
Log.d(TAG, "long thread onPostExecute call dismiss");
}
}.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
new AsyncTask<Void, Void, Void>(){
@Override
protected Void doInBackground(Void... params) {
try {
Log.d(TAG, "short thread doInBackground");
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
Log.d(TAG, "short thread onPostExecute");
finish();
Log.d(TAG, "short thread onPostExecute call finish");
}
}.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
}
@Override
protected void onDestroy() {
super.onDestroy();
Log.d(TAG, "onDestroy");
}
}
您可以尝试这样做,并找出解决此问题的最佳方法。
根据我的研究,至少有4种方法可以解决这个问题:
@erakitin的回答:调用isFinishing()来检查活动的状态
@Kapé的回答是:设置flag来检查活动的状态
使用try/catch来处理它。
调用onDestroy()中的AsyncTask.cancel(false)。它将阻止asynctask执行onPostExecute(),而是执行onCancelled()。
注意:onPostExecute()仍然会执行,即使你调用AsyncTask.cancel(false)在旧的Android操作系统,如Android 2.X.X。
你可以选择最适合你的。