如何将值从 Activity 传递到 Fragment？ [复制]

Question

目前这是我的Activity Class

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 Log Trace

中得到了这个错误

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。

1. 我该如何解决这个问题？

2. 如何将值或数据从活动传递到片段？

3. 还有其他的传值方式吗？

Answer 1

我不知道fragobj 是谁，但case 4 我认为你打错了，而不是：

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

你应该有：

fragment.setArguments(bundle);

至少应该对FragmentLipaChurches 进行不同的处理，因为您在那里创建了FragmentNaturalSite 的实例，但您将参数设置为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

从活动中传递价值使用这个

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

要获取 vlue，请在片段中的 onCreateView 中使用它

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