视图未附加到窗口管理器崩溃

Question

我正在使用ACRA报告应用程序崩溃.我收到一条View not attached to window manager错误消息,并认为我已通过pDialog.dismiss();在if语句中包装来修复它:

if (pDialog!=null) 
{
    if (pDialog.isShowing()) 
    {
        pDialog.dismiss();   
    }
}

它减少了View not attached to window manager我收到的崩溃数量,但我仍然得到一些,我不知道如何解决它.

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);
    }
}

表现:

    <activity
        android:name="pagename.CLASS" 
        android:configChanges="keyboard|keyboardHidden|orientation|screenSize|screenLayout"            
        android:label="@string/name" >
    </activity>

我错过了什么来阻止这次崩溃？

Answer 1

如何重现错误:

1. 在您的设备上启用此选项:Settings -> Developer Options -> Don't keep Activities.
2. 按Home键,而AsyncTask正在执行和ProgressDialog正在显示.

Android操作系统会在隐藏后立即销毁活动.当onPostExecute被称为Activity将处于"完成"状态并且ProgressDialog将不会附加Activity.

如何解决:

1. 检查方法中的活动状态onPostExecute.
2. 取消ProgressDialogin onDestroy方法.否则,android.view.WindowLeaked将抛出异常.此异常通常来自活动完成时仍处于活动状态的对话框.

试试这个固定代码:

public class YourActivity extends Activity {

    private void showProgressDialog() {
        if (pDialog == null) {
            pDialog = new ProgressDialog(StartActivity.this);
            pDialog.setMessage("Loading. Please wait...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
        }
        pDialog.show();
    }

    private void dismissProgressDialog() {
        if (pDialog != null && pDialog.isShowing()) {
            pDialog.dismiss();
        }
    }

    @Override
    protected void onDestroy() {
        dismissProgressDialog();
        super.onDestroy();
    }

    class LoadAllProducts extends AsyncTask<String, String, String> {

        // Before starting background thread Show Progress Dialog
        @Override
        protected void onPreExecute() {
            showProgressDialog();
        }

        //getting All products from url
        protected String doInBackground(String... args) {
            doMoreStuff("internet");
            return null;
        }

        // After completing background task Dismiss the progress dialog
        protected void onPostExecute(String file_url) {
            if (YourActivity.this.isDestroyed()) { // or call isFinishing() if min sdk version < 17
                return;
            }
            dismissProgressDialog();
            something(note);
        }
    }
}

Answer 2

问题可能是Activity已经finished或在progress of finishing.

添加一个检查isFinishing,并仅在此时关闭对话框false

if (!YourActivity.this.isFinishing() && pDialog != null) {
    pDialog.dismiss();
}

isFinishing: 检查此活动是否在完成过程中,或者是因为您调用finish了该活动,或者是其他人已请求完成此活动.

Answer 3

对于Dialog在a中创建Fragment,我使用以下代码:

ProgressDialog myDialog = new ProgressDialog(getActivity());
myDialog.setOwnerActivity(getActivity());
...
Activity activity = myDialog.getOwnerActivity();
if( activity!=null && !activity.isFinishing()) {
    myDialog.dismiss();
}

我使用这种模式来处理一个Fragment可能脱离的情况Activity.

Answer 4

了解守则如何在这里工作:

调用异步任务后,异步任务在后台运行.这是可取的.现在这个Async任务有一个附加到Activity的进度对话框,如果你问怎么做,请看代码:

pDialog = new ProgressDialog(CLASS.this);

您将Class.thisas上下文传递给参数.因此,"进度"对话框仍附加到活动.

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,而异步任务正在进行中,那么您正试图访问附加到活动的资源,即progess bar活动不再存在的时间点.

因此你得到:

java.lang.IllegalArgumentException: View not attached to window manager

.

解决方案:

1)确保在活动结束前取消或取消对话框.

2)完成活动,只有在关闭对话框后,即异步任务结束.

Answer 5

基于@erakitin答案,但也兼容Android版本<API级别17.可悲的是Activity.isDestroyed()仅支持API级别17,所以如果你的目标是像我一样的旧API级别,你将不得不自己检查一下.View not attached to window manager之后没有得到例外.

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
        }
    }
}

Answer 6

@Override
public void onPause() {
    super.onPause();

    if(pDialog != null)
        pDialog .dismiss();
    pDialog = null;
}

参考这个。