android - IllegalStateException( "You can not set Dialog' s OnCancelListener 或 OnDismissListener")

Question

此 DialogFragment 实现会导致

IllegalStateException( "You can not set Dialog's OnCancelListener or OnDismissListener")

。为什么？解决方案？

public class OkCThreadDialog1 extends DialogFragment{

DialogInterface.OnCancelListener onCancelListener;

public OkCThreadDialog1(){
}

public static OkCThreadDialog1 newInstance(String title, String message) {
    OkCThreadDialog1 frag = new OkCThreadDialog1();
    Bundle args = new Bundle();
    args.putString("title", title);
    args.putString("message", message);
    frag.setArguments(args);
    return frag;
}


public Dialog onCreateDialog(Bundle savedInstanceState){

    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());


    builder .setTitle(getArguments().getString("title"))
            .setMessage(getArguments().getString("message"))
            .setOnCancelListener(onCancelListener)
            .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                }})
            .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    getDialog().cancel();
                }});

    return builder.create();
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    // Verify that the host activity implements the callback interface
    try {
        onCancelListener = (DialogInterface.OnCancelListener) activity;
    } catch (ClassCastException e) {
        // The activity doesn't implement the interface, throw exception
        throw new ClassCastException(activity.toString()
                + " must implement OkCancelDialogListener");
    }
}
}

我的 Activity 实现 DialogInterface.OnCancelListener 如下:

public class MainActivity extends Activity implements OkCancelDialogListener{

static final String TAG ="MainActivity";

@Override
public void onCancel(DialogInterface dialog) {


}
}

builder.create(); 抛出异常。怎么了？

Answer 1

来自 Android documentation :

public Dialog onCreateDialog (Bundle savedInstanceState)

Override to build your own custom Dialog container. This istypically used to show an AlertDialog instead of a generic Dialog;when doing so, onCreateView(LayoutInflater, ViewGroup, Bundle) doesnot need to be implemented since the AlertDialog takes care of its owncontent.

This method will be called after onCreate(Bundle) and beforeonCreateView(LayoutInflater, ViewGroup, Bundle). The defaultimplementation simply instantiates and returns a Dialog class.

Note: DialogFragment own the Dialog.setOnCancelListener and Dialog.setOnDismissListener callbacks. You must not set them yourself.

To find out about these events, override onCancel(DialogInterface) andonDismiss(DialogInterface).

所以基本上，您必须覆盖 onDismiss 或 OnCancel 而不是 '.setOnCancelListener(onCancelListener)'。