在下面的代码中,我试图将布局中具有mainactivity选项卡的<fragment>的值传递给使用fragmentsetArgument()扩展getArgument()的另一个类。在运行应用程序时。 logcate引发NPE。我在代码中缺少什么?

主要活动:

public void onClick(View v) {
    // TODO Auto-generated method stub
    Fragment mSelectedFragment = null;

    switch (v.getId()) {
    case R.id.btn00:
        Bundle mBundle = new Bundle();
        String clicks = Integer.toString(i);
        mBundle.putString("btn1_clicks", clicks);
        mSelectedFragment = new Fragment00();
        mSelectedFragment.setArguments(mBundle);

        if (mSelectedFragment != null) {
            FragmentManager mFragmentManager = getFragmentManager();
            mFragmentManager.beginTransaction()
            .replace(R.id.fragment00ID, mSelectedFragment).commit();
        }
        i ++;
        break;
    }


Class_extends_fragment:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    View view = inflater.inflate(R.layout.fragment00, null);
    return view;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onActivityCreated(savedInstanceState);

    mTv = (TextView) getView().findViewById(R.id.fragment00Tv00);
    /*line 32->*/String str = getArguments().getString("btn1_clicks").toString();
    mTv.setText("the Button was clicked "+str+ " time(s)");
    Log.i(TAG, "onActivityCreated(): "+getArguments().getString("btn1_clicks").toString());
}


Logcat:

05-27 13:36:14.380: E/AndroidRuntime(11609): java.lang.RuntimeException: Unable to
start activity
ComponentInfo{com.example.fragments01/com.example.fragments01.MainActivity}:
java.lang.NullPointerException
05-27 13:36:14.380: E/AndroidRuntime(11609):    at
com.example.fragments01.Fragment00.onActivityCreated(Fragment00.java:32)
05-27 13:36:14.380: E/AndroidRuntime(11609):    at
android.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1860)

最佳答案

我认为的问题是,您正在检索getArguments()上的onActivityCreated,并且尚未创建捆绑包(您正在onClick中创建它)。您应该检查getArguments()是否返回null或从onClick中创建捆绑包。

旧版本为:

if (getArguments() != null){
    String str = getArguments().getString("btn1_clicks").toString();
}

10-08 17:34