Activity 泄露了最初添加在这里的窗口 com.android.internal.policy.impl.PhoneWindow$DecorView@46368a28

Question

这个问题让我发疯。我错过了一些基本但非常重要的知识，关于如何在活动中创建的新线程中处理长操作以及如何在长操作完成后修改文本等视图组件。

首先让我向您展示我的代码中发生此问题的部分：

mProgressDialog = ProgressDialog.show(mContext, "Tripplanner", "please wait...", true, false);
connectAndGetRoute();


private void connectAndGetRoute(){

    new Thread(){
        @Override
        public void run() {
            try {
            if(!connectTo9292ov()) return;// conncetto9292ov() connects to a website, parses the reasult into an arraylist. The arraylist contains route.

            } catch(UnknownHostException e){
                Toast.makeText(mContext, "failed to connect to server", Toast.LENGTH_LONG).show();
            }catch (ClientProtocolException e) {
               Toast.makeText(mContext, "failed to connect to server", Toast.LENGTH_LONG).show();                   
        } catch (IOException e) {
                Toast.makeText(mContext, "failed to connect to server", Toast.LENGTH_LONG).show();
            }

            handler.post(runConnection);
        }

    }.start();

    handler = new Handler();
    runConnection = new Runnable(){
        @Override
        public void run() {
            mProgressDialog.dismiss();
            showOnScreen();
        }   
    };
}

这是我得到的错误：

ERROR/WindowManager(8297): Activity mp.tripplanner.OvPlanner has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@46368a28 that was originally added here
ERROR/WindowManager(8297): android.view.WindowLeaked: Activity mp.tripplanner.OvPlanner has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@46368a28 that was originally added here
ERROR/WindowManager(8297): at android.view.ViewRoot.<init>(ViewRoot.java:251)
ERROR/WindowManager(8297): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
ERROR/WindowManager(8297): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
ERROR/WindowManager(8297): at android.view.Window$LocalWindowManager.addView(Window.java:424)
ERROR/WindowManager(8297): at android.app.Dialog.show(Dialog.java:241)
ERROR/WindowManager(8297): at android.app.ProgressDialog.show(ProgressDialog.java:107)
ERROR/WindowManager(8297): at android.app.ProgressDialog.show(ProgressDialog.java:95)
ERROR/WindowManager(8297): at mp.tripplanner.OvPlanner$3.onClick(OvPlanner.java:351)
ERROR/WindowManager(8297): at android.view.View.performClick(View.java:2408)
ERROR/WindowManager(8297): at android.view.View$PerformClick.run(View.java:8817)
ERROR/WindowManager(8297): at android.os.Handler.handleCallback(Handler.java:587)
ERROR/WindowManager(8297): at android.os.Handler.dispatchMessage(Handler.java:92)
ERROR/WindowManager(8297): at android.os.Looper.loop(Looper.java:144)
ERROR/WindowManager(8297): at android.app.ActivityThread.main(ActivityThread.java:4937)
ERROR/WindowManager(8297): at java.lang.reflect.Method.invokeNative(Native Method)
ERROR/WindowManager(8297): at java.lang.reflect.Method.invoke(Method.java:521)
ERROR/WindowManager(8297): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
ERROR/WindowManager(8297): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
ERROR/WindowManager(8297): at dalvik.system.NativeStart.main(Native Method)

但是在上面一条之前的日志中写入了另外一条错误信息，即：

ERROR/AndroidRuntime(8297): FATAL EXCEPTION: Thread-9
ERROR/AndroidRuntime(8297): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
ERROR/AndroidRuntime(8297): at android.os.Handler.<init>(Handler.java:121)
ERROR/AndroidRuntime(8297): at android.widget.Toast.<init>(Toast.java:68)
ERROR/AndroidRuntime(8297): at android.widget.Toast.makeText(Toast.java:231)
ERROR/AndroidRuntime(8297): at mp.tripplanner.OvPlanner$4.run(OvPlanner.java:371)

感谢您的帮助。

Answer 1

只是一个快速的想法。

我认为，这是您在线程中的祝酒词。尝试将它们注释掉。

如果您仍想显示消息，请保存线程的状态并在您的处理程序中处理它。从 finally 块中调用你的处理程序

mProgressDialog = ProgressDialog.show(mContext, "Tripplanner", "please wait...", true, false);
connectAndGetRoute();


private void connectAndGetRoute(){

    new Thread(){
        @Override
        public void run() {
            try {
            if(!connectTo9292ov()) return;// conncetto9292ov() connects to a website, parses the reasult into an arraylist. The arraylist contains route.

            } catch(UnknownHostException e){
                // an int member of your activity
                threadStatus = 404;
                // Toast.makeText(mContext, "failed to connect to server", Toast.LENGTH_LONG).show();
            }catch (ClientProtocolException e) {
                threadStatus = 404;
               // Toast.makeText(mContext, "failed to connect to server", Toast.LENGTH_LONG).show();                   
        } catch (IOException e) {
                threadStatus = 404;
                // Toast.makeText(mContext, "failed to connect to server", Toast.LENGTH_LONG).show();
            }
            finally {
            handler.post(runConnection);}
        }

    }.start();

    handler = new Handler();
    runConnection = new Runnable(){
        @Override
        public void run() {
            if (threadStatus == 404) { Toast.makeText(mContext, "failed to connect to server", Toast.LENGTH_LONG).show();}
            else {
            mProgressDialog.dismiss();
            showOnScreen();}
        }   
    };
}

Answer 2

您的Handler 需要在您的 UI 线程中创建，它才能更新 UI。 然后我会使用处理程序的sendMessage 方法，而不是发布可运行的：

private static final int HANDLER_MESSAGE_ERROR = 0;
private static final int HANDLER_MESSAGE_COMPLETED = 1;
...
private void connectAndGetRoute(){
    new Thread(){
        @Override
        public void run() {
            try {
                if(!connectTo9292ov()) return;

            } catch(UnknownHostException e){
                sendMessage(HANDLER_MESSAGE_ERROR);
            } catch (ClientProtocolException e) {
                sendMessage(HANDLER_MESSAGE_ERROR);
            } catch (IOException e) {
                sendMessage(HANDLER_MESSAGE_ERROR);
            } finally {
                sendMessage(HANDLER_MESSAGE_COMPLETED);
            }
        }
        private void sendMessage(int what){
            Message msg = Message.obtain();
            msg.what = what;
            mHandler.sendMessage(msg);
        }
    }.start();

}
...
private Handler mHandler = new Handler(){
    @Override
    public void handleMessage(Message msg) {
        switch(msg.what){
        case HANDLER_MESSAGE_ERROR:
            Toast.makeText(mContext, "failed to connect to server", Toast.LENGTH_LONG).show();
            break;
        case HANDLER_MESSAGE_COMPLETED:
            mProgressDialog.dismiss();
            showOnScreen();
            break;
        default:
            Log.w("MyTag","Warning: message type \""+msg.what+"\" not supported");
        }
    }
}

Answer 3

示例代码：

new Thread(new Runnable() {                 
                @Override
                public void run() {
                    doNotUIthings();
                    updateUI.sendEmptyMessage(0);   //Update ui in UI thread
                }
                private Handler updateUI = new Handler(){
                    @Override
                    public void dispatchMessage(Message msg) {
                        super.dispatchMessage(msg);
                        updateUI();
                    }
                };
            }).start();

但我建议使用 AsyncTask 而不是 Java 线程。