Question

在TrainingDetailFragment中，我需要启动一个SwimlogListActivity来显示与Training详细信息相关的所有swimlog的列表。

所以在我的TrainingDetailFragment中，我编写了一个Intent并将training_id作为额外的函数传递（调试器日志：mItem.id：2）

public class TrainingDetailFragment extends Fragment {
    ....
    Intent swimlogs = new Intent(getActivity(), SwimlogListActivity.class);
    swimlogs.putExtra("trainingID", mItem.id);
    startActivity(swimlogs);

在SwimlogListActivity中，我测试我是否可以获得trainingID arg ..

 public class SwimlogListActivity extends FragmentActivity implements SwimlogListFragment.Callbacks {

    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_swimlog_list);

    Intent intent = getIntent();
    if(intent != null) {
        String trainingID = intent.getStringExtra("trainingID");
        Log.i(TAG, "SwinglogListActivity - onCreate() with trainingID: "  + trainingID);
    }

但我得到一个trainingID null ..... SwinglogListActivity - onCreate（）with trainingID：null

我哪里可能出错？ btw Happy 2014 !!

Answer 1

几乎可以肯定mItem.id不是String，如果它是int，例如，使用intent.getIntExtra

获取它

Answer 2

   Bundle extras = getIntent().getExtras();
     if (extras != null) {
     String datas= extras.getString("EXTRA_ID");
     if (datas!= null) {
       // do stuff
    }        
 }

了解更多信息：link

Answer 3

认为您的mItem.id是整数，因此您只需将SwimlogListActivity的代码替换为：

...
Intent mIntent = getIntent();
if(mIntent != null) {
    int trainingID = mIntent.getIntExtra("trainingID", 0);
    Log.i(TAG, "SwinglogListActivity - onCreate() with trainingID: "  + trainingID);
}

当从intent传递到目标活动时，android extra arg为null

3 个答案: