DialogFragment和onDismiss

Question

我使用的是一个DialogFragment，我在Activity中显示如下所示

DialogFragmentImage dialog = DialogFragmentImage.newInstance(createBitmap());
dialog.onDismiss(dialog);.onDismiss(this);          
dialog.show(getFragmentManager(), "DialogFragmentImage");

我想在我的Activity中检查DialogFragment何时关闭(例如，当按下back按钮时)。我该怎么做呢？我怎样才能“告诉”我的activity DialogFragment已经被关闭了？

Answer 1

让你的活动实现OnDismissListener

public final class YourActivity extends Activity implements DialogInterface.OnDismissListener {

    @Override
    public void onDismiss(final DialogInterface dialog) {
        //Fragment dialog had been dismissed
    }

}

DialogFragment已经实现了OnDismissListener，只需覆盖该方法并调用Activity即可。

public final class DialogFragmentImage extends DialogFragment {

    ///blah blah

    @Override
    public void onDismiss(final DialogInterface dialog) {
        super.onDismiss(dialog);
        final Activity activity = getActivity();
        if (activity instanceof DialogInterface.OnDismissListener) {
            ((DialogInterface.OnDismissListener) activity).onDismiss(dialog);
        }
    }

}

如果使用childFragment管理器(API>=17)从片段启动对话框，则可以使用getParentFragment与父片段上的onDismissListener对话：

public final class DialogFragmentImage extends DialogFragment {

    ///blah blah

    @Override
    public void onDismiss(final DialogInterface dialog) {
        super.onDismiss(dialog);
        Fragment parentFragment = getParentFragment();
        if (parentFragment instanceof DialogInterface.OnDismissListener) {
            ((DialogInterface.OnDismissListener) parentFragment).onDismiss(dialog);
        } 
    }

}

Answer 2

这是我的答案。有点晚了，但可能对路过的人有好处。

FragmentManager fm = getFragmentManager();

YourDialogFragment dialog = new YourDialogFragment();
dialog.show(fm,"MyDialog");

fm.executePendingTransactions();
dialog.getDialog().setOnDismissListener(new DialogInterface.OnDismissListener() {
                    @Override
                    public void onDismiss(DialogInterface dialogInterface) {
                       //do whatever you want when dialog is dismissed
                    }
                });

我们需要打电话给

fm.executePendingTransactions(); 

以确保已经执行了FragmentTransaction工作。否则，在调用setOnDismissListener()时可能会发生NullPointerException。

如果有什么差错，很抱歉。希望这能有所帮助。

Answer 3

这是一个古老的问题，但我没有找到我满意的解决方案。我不喜欢将任何侦听器传递给我的DialogFragment或设置一个TargetFragment，因为这可能会在方向更改时中断。你觉得这个怎么样？

        MyDialog d = new MyDialog();
        d.show(fragmentManager, "tag");
        fragmentManager.registerFragmentLifecycleCallbacks(new FragmentManager.FragmentLifecycleCallbacks() {
            @Override
            public void onFragmentViewDestroyed(FragmentManager fm, Fragment f) {
                super.onFragmentViewDestroyed(fm, f);
                //do sth      
        fragmentManager.unregisterFragmentLifecycleCallbacks(this);
                }
            }, false);