在Android中的三个活动之间传递捆绑

Question

I have three activities that I can call A, B and C. I want to pass information between the three like this: A-->B-->C-->A. In AI want to check if there is a bundle passed (the first time, start-up, there won't be one for example). The data is passed from AB with a normal bundle. From B-->CI use this:

Intent i = new Intent(getApplicationContext(), FlashcardView.class);
             i.putExtra("rattning", rattning);
             i.putExtra("noqs", noqs);
             i.putExtra("categoryid", categoryid);
             CreateTestView.this.finish();
             startActivityForResult(i, 0);

It is received and then sent onwards to A like this:

  Intent data = new Intent(FlashcardView.this, MenuView.class);
                       data.putExtra("point", point);
                       data.putExtra("noqs", noqs);
                       setResult(RESULT_OK, data);
                       finish();

It is received at A like this:

 @Override 
   protected void onActivityResult( int req, int resp, Intent data ) {
        super.onActivityResult(req, resp, data);
        // process your received "data" from GameActivity ...
        Bundle b = getIntent().getExtras();
        noqs = b.getInt("noqs");
        point = b.getInt("point");
        mTvCat.setText("hhhhhh"+point+noqs);
        publishOnFacebook(point,noqs);
    }

It seems though like the bundle is lost on the way from C-->A. When I passed it back from C-->B there was no problem. I think this happens cause B is the activity that starts C, and therefore C falls back to B, not A. I made a go-around by calling finish() on B, so C goes back to A instead. BUt in doing this I lose the bundle. Or at least I think so.

Has anyone seen this before? Is there a better way of doing this? How can I prevent losing the bundle on a passing between more than two activities? THanks!

Edit:

Edit: Here is the error code on receiving the broadcast:

  03-07 12:57:59.394: ERROR/AndroidRuntime(803): java.lang.RuntimeException: Error receiving broadcast Intent { act=my_action (has extras) } in com.crystalcodeab.Flashcard.MenuView$1@47681ad0
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at android.app.ActivityThread$PackageInfo$ReceiverDispatcher$Args.run(ActivityThread.java:981)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at android.os.Handler.handleCallback(Handler.java:587)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at android.os.Handler.dispatchMessage(Handler.java:92)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at android.os.Looper.loop(Looper.java:143)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at android.app.ActivityThread.main(ActivityThread.java:5068)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at java.lang.reflect.Method.invokeNative(Native Method)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at java.lang.reflect.Method.invoke(Method.java:521)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at dalvik.system.NativeStart.main(Native Method)
03-07 12:57:59.394: ERROR/AndroidRuntime(803): Caused by: java.lang.NullPointerException
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at com.crystalcodeab.Flashcard.MenuView$1.onReceive(MenuView.java:56)
03-07 12:57:59.394: ERROR/AndroidRuntime(803):     at 

Answer 1

I think the problem lies in how you finish activity B. When you finish Activity B, the result from B is sent back to A and the Activity is gone. C has no way of knowing it should return its result to A, as it is only aware of Activity B.

My suggestion to you is that you should use a BroadcastReceiver in Activity A. Then in Activity C you can send a Broadcast with the data you wish to be received by A:

In A:

IntentFilter filter = new IntentFilter("my.action");
BroadcastReceiver receiver = new BroadcastReceiver() {
  public void onReceive(Context context, Intent intent) {
    if(intent.getAction().equals("my.action")) {
      // Do my stuff
    }
  }
}
registerReceiver(receiver, filter);

In C:

Intent data = new Intent("my.action");
data.putExtra("point", point);
data.putExtra("noqs", noqs);
sendBroadcast(data);

Answer 2

You may wish to use Fragment s instead of activities in your game and manage the state transition within the FragmentManager instead of trying to use the Activity stack. It seems like it might be a bit easier to manage.

Answer 3

完成活动B后，为什么使用新的Intent而不是getIntent()方法？