如何从TabHost活动返回结果(startActivityForResult)？

Question

我的例子中有3个类:A类,主要活动.A类调用startActivityForResult:

Intent intent = new Intent(this, ClassB.class);
startActivityForResult(intent, "STRING");

B类,这个类是一个TabActivity:

Intent intent = new Intent(this, ClassC.class);
tabHost.addTab...

C类,这个类是一个常规的Activity:

Intent intent = this.getIntent();
intent.putExtra("SOMETHING", "EXTRAS");
this.setResult(RESULT_OK, intent);
finish();

onActivityResult在类A中调用,但resultCode RESULT_CANCELED代替,RESULT_OK返回的intent为null.如何从TabHost中的Activity返回一些内容？

我意识到问题是我的C类实际上是在B类中运行,而B类是返回RESULT_CANCELED到A类的.我只是不知道一个解决方法.

Answer 1

天啊!花了几个小时下载Android源代码后,我终于找到了解决方案.

如果查看Activity类,您将看到,finish()如果有mParent属性设置,该方法仅发送回结果null.否则结果会丢失.

public void finish() {
    if (mParent == null) {
        int resultCode;
        Intent resultData;
        synchronized (this) {
            resultCode = mResultCode;
            resultData = mResultData;
        }
        if (Config.LOGV) Log.v(TAG, "Finishing self: token=" + mToken);
        try {
            if (ActivityManagerNative.getDefault()
                .finishActivity(mToken, resultCode, resultData)) {
                mFinished = true;
            }
        } catch (RemoteException e) {
            // Empty
        }
    } else {
        mParent.finishFromChild(this);
    }
}

所以我的解决方案是将结果设置为父活动(如果存在),如下所示:

Intent data = new Intent();
 [...]
if (getParent() == null) {
    setResult(Activity.RESULT_OK, data);
} else {
    getParent().setResult(Activity.RESULT_OK, data);
}
finish();

如果有人再次寻找此问题的解决方法,我希望这会有所帮助.

Answer 2

http://tylenoly.wordpress.com/2010/10/27/how-to-finish-activity-with-results/

略加修改"param_result"

/* Start Activity */
public void onClick(View v) {
    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.setClassName("com.thinoo.ActivityTest", "com.thinoo.ActivityTest.NewActivity");
    startActivityForResult(intent,90);
}
/* Called when the second activity's finished */
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch(requestCode) {
    case 90:
        if (resultCode == RESULT_OK) {
            Bundle res = data.getExtras();
            String result = res.getString("param_result");
            Log.d("FIRST", "result:"+result);
        }
        break;
    }
}

private void finishWithResult()
{
    Bundle conData = new Bundle();
    conData.putString("param_result", "Thanks Thanks");
    Intent intent = new Intent();
    intent.putExtras(conData);
    setResult(RESULT_OK, intent);
    finish();
}

Answer 3

Intent.FLAG_ACTIVITY_FORWARD_RESULT？

如果设置并且此意图用于从现有活动启动新活动,则现有活动的回复目标将转移到新活动.