传递结果 ResultInfo(who=null, request=1, result=0, data=null) 失败

Question

我正在尝试将结果显示为 toast，但应用程序在此行崩溃 Plant plant = (Plant) data.getSerializableExtra(PlantResultActivity.PLANT_RESULT);

PlantResultActivity：

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    // TODO Auto-generated method stub
    super.onListItemClick(l, v, position, id);

    // get the item that the user clicked
    Plant plant = (Plant) getListAdapter().getItem(position);

    // EveryThing went fine
    getIntent().putExtra(PLANT_RESULT, plant);

    // Finish this Intent
    finish();
}

高级搜索活动：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, data);
    //are we getting data returend from the plantResultIntent? If so, this if test will evaluate to true, because
    //we passed the PLANT_RESULTS constant in when invoked that intent
    if(requestCode == PLANT_RESULTS){
        //fetch the selected data using the constant that we have using as a key
        Plant plant = (Plant) data.getSerializableExtra(PlantResultActivity.PLANT_RESULT);

        //This Toast will be invoked if we recieved a result from plantResultIntent
        Toast.makeText(this, "Recieved Result " + plant, Toast.LENGTH_LONG).show();


    }
}

Answer 1

您错过了setResult 调用，并且返回的意图（您在onActivityResult 中使用的意图）为空

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    // TODO Auto-generated method stub
    super.onListItemClick(l, v, position, id);

    // get the item that the user clicked
    Plant plant = (Plant) getListAdapter().getItem(position);
    Intent intent = new Intent();
    // EveryThing went fine
    intent.putExtra(PLANT_RESULT, plant);
    setResult(RESULT_OK, intent);
    // Finish this Intent
    finish();
}