Question

目前这是我的活动类

Fragment fragment = null;
        switch (position) {
        case 0:
            fragment = new FragmentTripPlan();
            break;
        case 1:
            fragment = new FragmentCulturalHistorical();
            Toast.makeText(this, "cultural", Toast.LENGTH_SHORT).show();
            break;
        case 2:
            fragment = new FragmentLeisureRecreational();
            Toast.makeText(this, "Leisure", Toast.LENGTH_SHORT).show();

            break;
        case 3:
            fragment = new FragmentLipaChurches();
            break;
        case 4:
            fragment = new FragmentNaturalSite();
            Bundle bundle = new Bundle();
            bundle.putString("edttext", "From Activity");
            FragmentNaturalSite fragobj = new FragmentNaturalSite();
            fragobj.setArguments(bundle);
            break;
        case 5:
            fragment = new FragmentCreateReport();
            break;
        case 6:
            fragment = new FragmentAbout();
            break;

        default:
            break;

这是我的片段类

public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_lipa_churches, container, false);   
    // ******* vvvvvv
    Bundle bundle = getArguments();
    String strtext = bundle .getString("edttext");
return rootView;
}

我在日志跟踪

中遇到了错误

01-10 13:51:43.020: E/AndroidRuntime(13708): FATAL EXCEPTION: main
01-10 13:51:43.020: E/AndroidRuntime(13708): java.lang.NullPointerException
01-10 13:51:43.020: E/AndroidRuntime(13708):    at com.c4a.itravellipaph.FragmentLipaChurches.onCreateView(FragmentLipaChurches.java:26)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.app.Fragment.performCreateView(Fragment.java:1695)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:903)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1075)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.app.BackStackRecord.run(BackStackRecord.java:682)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1455)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.app.FragmentManagerImpl$1.run(FragmentManager.java:441)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.os.Handler.handleCallback(Handler.java:725)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.os.Handler.dispatchMessage(Handler.java:92)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.os.Looper.loop(Looper.java:137)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at android.app.ActivityThread.main(ActivityThread.java:5279)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at java.lang.reflect.Method.invokeNative(Native Method)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at java.lang.reflect.Method.invoke(Method.java:511)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
01-10 13:51:43.020: E/AndroidRuntime(13708):    at dalvik.system.NativeStart.main(Native Method)

问题。

我该如何解决这个问题？
如何将活动中的值或数据传递给片段？
还有其他方式传递价值吗？

Answer 1

我不知道谁是fragobj，但在case 4我认为你有错字，而不是：

FragmentLipaChurches fragobj = new FragmentLipaChurches();
fragobj.setArguments(bundle);

你应该：

fragment.setArguments(bundle);

至少FragmentLipaChurches应该以不同的方式处理，因为您正在创建FragmentNaturalSite的实例，但是您要将参数设置为FragmentLipaChurches。所以FragmentNaturalSite没有设置参数，这就是NPE的原因。

Answer 2

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
           Bundle b = getActivity().getIntent().getExtras();
           String strtext = getArguments().getString("edttext");  
           View view = inflater.inflate(R.layout.categoryfragment, container, false);
           return view;
 }

Answer 3

从活动传递值使用此

Bundle bun = new Bundle();
bun.putString("pathimage", path);
fragment_setting.setArguments(bun);

获取值在片段

中的onCreateView中使用它

Bundle b = getArguments();
String path = b.getString("pathimage");

如何将值从Activity传递给Fragment？

3 个答案: