或者像下面这样共享ViewModel:

public class SharedViewModel extends ViewModel {
    private final MutableLiveData<Item> selected = new MutableLiveData<Item>();

    public void select(Item item) {
        selected.setValue(item);
    }

    public LiveData<Item> getSelected() {
        return selected;
    }
}


public class MasterFragment extends Fragment {
    private SharedViewModel model;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        model = ViewModelProviders.of(getActivity()).get(SharedViewModel.class);
        itemSelector.setOnClickListener(item -> {
            model.select(item);
        });
    }
}

public class DetailFragment extends Fragment {
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        SharedViewModel model = ViewModelProviders.of(getActivity()).get(SharedViewModel.class);
        model.getSelected().observe(this, { item ->
           // Update the UI.
        });
    }
}

https://developer.android.com/topic/libraries/architecture/viewmodel#sharing_data_between_fragments

如果你想发送参数并从第二个片段接收结果，你可以使用fragment。setargarguments来完成这个任务

static class FirstFragment extends Fragment {
    final Handler mUIHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case 101: // receive the result from SecondFragment
                Object result = msg.obj;
                // do something according to the result
                break;
            }
        };
    };

    void onStartSecondFragments() {
        Message msg = Message.obtain(mUIHandler, 101, 102, 103, new Object()); // replace Object with a Parcelable if you want to across Save/Restore
                                                                               // instance
        putParcelable(new SecondFragment(), msg).show(getFragmentManager().beginTransaction(), null);
    }
}

static class SecondFragment extends DialogFragment {
    Message mMsg; // arguments from the caller/FirstFragment

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onViewCreated(view, savedInstanceState);
        mMsg = getParcelable(this);
    }

    void onClickOK() {
        mMsg.obj = new Object(); // send the result to the caller/FirstFragment
        mMsg.sendToTarget();
    }
}

static <T extends Fragment> T putParcelable(T f, Parcelable arg) {
    if (f.getArguments() == null) {
        f.setArguments(new Bundle());
    }
    f.getArguments().putParcelable("extra_args", arg);
    return f;
}
static <T extends Parcelable> T getParcelable(Fragment f) {
    return f.getArguments().getParcelable("extra_args");
}

好吧，现在回答可能为时已晚，但这是我从DialogFragment中获得结果的方法。非常类似于@brandon的回答。 这里我从一个片段调用DialogFragment，只是把这段代码放在你调用你的对话框的地方。

FragmentManager fragmentManager = getFragmentManager();
            categoryDialog.setTargetFragment(this,1);
            categoryDialog.show(fragmentManager, "dialog");

where categoryDialog是我的DialogFragment，我想调用这之后，在你的DialogFragment的实现中放置这段代码，你在意图中设置你的数据。resultCode的值为1，可以设置或使用system Defined。

            Intent intent = new Intent();
            intent.putExtra("listdata", stringData);
            getTargetFragment().onActivityResult(getTargetRequestCode(), resultCode, intent);
            getDialog().dismiss();

现在回到调用片段并实现该方法。在if条件中使用resultCode和requestCode检查数据有效性或结果成功。

 @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);        
        //do what ever you want here, and get the result from intent like below
        String myData = data.getStringExtra("listdata");
Toast.makeText(getActivity(),data.getStringExtra("listdata"),Toast.LENGTH_SHORT).show();
    }

我发现了一个简单的方法: 实现这个是你的dialogFragment，

  CallingActivity callingActivity = (CallingActivity) getActivity();
  callingActivity.onUserSelectValue("insert selected value here");
  dismiss();

然后在调用Dialog Fragment的activity中创建相应的函数:

 public void onUserSelectValue(String selectedValue) {

        // TODO add your implementation.
      Toast.makeText(getBaseContext(), ""+ selectedValue, Toast.LENGTH_LONG).show();
    }

祝酒词是为了证明它是有效的。为我工作。

或者像下面这样共享ViewModel:

public class SharedViewModel extends ViewModel {
    private final MutableLiveData<Item> selected = new MutableLiveData<Item>();

    public void select(Item item) {
        selected.setValue(item);
    }

    public LiveData<Item> getSelected() {
        return selected;
    }
}


public class MasterFragment extends Fragment {
    private SharedViewModel model;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        model = ViewModelProviders.of(getActivity()).get(SharedViewModel.class);
        itemSelector.setOnClickListener(item -> {
            model.select(item);
        });
    }
}

public class DetailFragment extends Fragment {
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        SharedViewModel model = ViewModelProviders.of(getActivity()).get(SharedViewModel.class);
        model.getSelected().observe(this, { item ->
           // Update the UI.
        });
    }
}

https://developer.android.com/topic/libraries/architecture/viewmodel#sharing_data_between_fragments

我很惊讶地看到，没有人建议使用本地广播进行DialogFragment到Activity的通信!我发现它比其他建议更简单、更清晰。本质上，您为您的Activity注册侦听广播，并从您的DialogFragment实例发送本地广播。简单。有关如何设置它的一步一步的指南，请参见这里。