Question

我有一个为Android 4.3.1 API18开发的基本Android应用程序。在我的应用程序中，我使用以下代码启动了StartActivityForResult：

footerView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
        Intent intent = 
            new Intent(ThisActivityClass.this,OtherActivityClass.class);
        startActivityForResult(intent, 1);
    }
});

新Activity按预期运行，并使用以下代码将结果返回给第一个Activity：

final Button submitButton = (Button) findViewById(R.id.submitButton);
submitButton.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {

        Intent data = new Intent();

        data.putExtra("A", "DONT_CARE");        

        setResult(RESULT_OK,data);
        finish();
    }
});

返回调用Activity，在onActivityResult中成功收到结果：

@Override
protected void onActivityResult
  (int requestCode, int resultCode, Intent data) {
    if(resultCode == Activity.RESULT_OK){
        switch(requestCode)
        {
        case 1:
            ToDoItem item = new ToDoItem(data);
            //...Saving Data from Intent
            break;
        }

    }
}

到目前为止一切顺利。之后，当前活动按以下顺序调用其方法，这意味着一切正常： 1. onStart（） 2. onResume（）注意：onPause \ onStop没有被调用！

从这里出现问题 - 模拟器显示黑屏 - 操作栏可见。

并且调试器在最后一行的doCallbacks方法中的Choreographer.class上停止，在结束括号中：

void doCallbacks(int callbackType, long frameTimeNanos) {
    CallbackRecord callbacks;
    synchronized (mLock) {
        // We use "now" to determine when callbacks become due because it's possible
        // for earlier processing phases in a frame to post callbacks that should run
        // in a following phase, such as an input event that causes an animation to start.
        final long now = SystemClock.uptimeMillis();
        callbacks = mCallbackQueues[callbackType].extractDueCallbacksLocked(now);
        if (callbacks == null) {
            return;
        }
        mCallbacksRunning = true;
    }
    try {
        for (CallbackRecord c = callbacks; c != null; c = c.next) {
            if (DEBUG) {
                Log.d(TAG, "RunCallback: type=" + callbackType
                        + ", action=" + c.action + ", token=" + c.token
                        + ", latencyMillis=" + (SystemClock.uptimeMillis() - c.dueTime));
            }
            c.run(frameTimeNanos);
        }
    } finally {
        synchronized (mLock) {
            mCallbacksRunning = false;
            do {
                final CallbackRecord next = callbacks.next;
                recycleCallbackLocked(callbacks);
                callbacks = next;
            } while (callbacks != null);
        }
    }
}

LogCat显示以下输出，注意日志末尾显示的onActivityResult，onStart，onResume的调用：

03-22 08:54:26.308: D/gralloc_goldfish(1224): Emulator without GPU emulation detected.
03-22 08:54:26.588: I/Choreographer(1224): Skipped 41 frames!  The application may be doing too much work on its main thread.
03-22 08:54:46.268: I/Lab-UserInterface(1224): Entered footerView.OnClickListener.onClick()
03-22 08:54:46.398: I/Lab-UserInterface(1224): ToDoManagerActivity entered onPause
03-22 08:54:51.039: I/Choreographer(1224): Skipped 40 frames!  The application may be doing too much work on its main thread.
03-22 08:54:52.759: I/Choreographer(1224): Skipped 34 frames!  The application may be doing too much work on its main thread.
03-22 08:54:56.249: I/Choreographer(1224): Skipped 44 frames!  The application may be doing too much work on its main thread.
03-22 08:54:58.758: I/Lab-UserInterface(1224): Entered submitButton.OnClickListener.onClick()
03-22 08:54:59.261: I/Lab-UserInterface(1224): Entered onActivityResult()
03-22 08:56:45.298: I/Lab-UserInterface(1224): ToDoManagerActivity entered onStart
03-22 08:56:45.298: I/Lab-UserInterface(1224): ToDoManagerActivity entered onResume
03-22 08:56:45.338: I/Choreographer(1224): Skipped 27628 frames!  The application may be doing too much work on its main thread.
03-22 08:56:45.489: D/dalvikvm(1224): GC_FOR_ALLOC freed 108K, 6% free 3711K/3936K, paused 37ms, total 53ms

我尝试了很多东西，无法提出解决方案： 1.无法在线找到解决方案 2.我用try catch块包装每个方法

您如何描述问题？活动是否失去了焦点（我想不是）？前台应用程序进入了一个weired状态？可以使用哪些其他调试工具来查找问题？最重要的是，你是否遇到过这个问题\知道如何解决它？

此致 hoshmy

从具有结果的其他活动返回后，Android应用程序显示黑屏

0 个答案: