Android DialogFragment onViewCreated not called

问题

I am using android compatibility library (v4 revision 8). In the custom DialogFragment the overrided method onViewCreated is not getting called.For eg.

public class MyDialogFragment extends DialogFragment{
    private String mMessage;
    public MyDialogFragment(String message) {
        mMessage = message;
    }

    @Override
    public Dialog onCreateDialog( Bundle savedInstanceState){
        super.onCreateDialog(savedInstanceState);
        Log.d("TAG", "onCreateDialog");
        setRetainInstance(true); 
        //....do something
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        Log.d("TAG", "onViewCreated");
        //...do something
    }
}

onViewCreated is not getting logged.

回答1:

Well, the docs for onViewCreated state "Called immediately after onCreateView(LayoutInflater, ViewGroup, Bundle) has returned".

DialogFragment uses onCreateDialog and not onCreateView, so onViewCreated is not fired. (Would be my working theory, I haven't dived into the android source to confirm).

回答2:

From my testing, onViewCreated isn't called if onCreateView returns null, which is the default behavior, so if you're not using onCreateView but manually calling setContentView in onCreateDialog, you can manually call onViewCreated from onCreateDialog:

@Override public Dialog onCreateDialog(Bundle savedInstanceState) {
    final Dialog d = super.onCreateDialog(savedInstanceState);
    d.setContentView(R.layout.my_dialog);
    // ... do stuff....
    onViewCreated(d.findViewById(R.id.dialog_content), savedInstanceState);
    return d;
}

In this case, make sure the root element in my_dialog.xml has android:id="@+id/dialog_content"

回答3:

You can see what's happening from the source code:

First, since you don't override onCreateView() your fragment's view will be null. This can be seen from the source code of Fragment -- the default returns null:

// android.support.v4.app.Fragment.java
@Nullable
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
        @Nullable Bundle savedInstanceState) {
    return null;
}

Second, since you're view is null the FragmentManager will not call onViewCreated(). From the source code of FragmentManager:

// android.support.v4.app.FragmentManager.java
if (f.mView != null) {
    f.mInnerView = f.mView;
    // ... 

    // only called if the fragments view is not null!
    f.onViewCreated(f.mView, f.mSavedFragmentState);
} else {
    f.mInnerView = null;
}

回答4:

According to the doc (Selecting Between Dialog or Embedding) and having it tested by myself, you can override OnCreateView, inflate it with your custom layout and return it. OnViewCreated will be launched

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
           View view = inflater.inflate(R.layout.custom_layout, null);
           //do whatever        
           return view; 
    }

回答5:

This is how I make sure onViewCreated is called in kotlin:

class MyDialog: DialogFragment() {

    private lateinit var dialogView: View

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        dialogView = LayoutInflater.from(context).inflate(R.layout.dialog, null)
        val dialog = MaterialAlertDialogBuilder(context!!)
                .setView(dialogView)
                .create()

        return dialog
    }

    // Need to return the view here or onViewCreated won't be called by DialogFragment, sigh
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return dialogView
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        // Yay it's now called!
    }

    override fun onDestroyView() {
        dialogView = null
        super.onDestroyView()
    }
}

来源：https://stackoverflow.com/questions/10594992/android-dialogfragment-onviewcreated-not-called

标签

android

android-support-library

android-dialogfragment