Question

我有一个自定义对话框设置，里面是button，我想将功能放入其中，比如转到下一个Activity或者在这种情况下关闭对话框。但是，当我单击它时，它返回一个Null引用异常。

到目前为止，这是我的代码：

XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <Button
        android:id="@+id/dialogButtonOK"
        android:layout_width="100px"
        android:layout_height="wrap_content"
        android:text=" Ok "
        android:layout_marginTop="5dp"
        android:layout_marginRight="5dp"
        android:layout_below="@+id/image" />
</RelativeLayout>

活动代码：

    protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);


        SetContentView(Resource.Layout.Main);

        Button button = FindViewById<Button>(Resource.Id.MyButton);

        button.Click += delegate {

            Dialog dialog = new Dialog(this);
            dialog.SetContentView(Resource.Layout.dialog);
            dialog.SetTitle("Titolo");

            Button dialogbutton = FindViewById<Button>(Resource.Id.dialogButtonOK);

            dialogbutton.Click += delegate
            {
                dialog.Dismiss();
            };

            dialog.Show();

        };
    }
}

我已使用按钮dialogbutton = FindViewById<Button>(Resource.Id.dialogButtonOK);正确引用了对话框中的按钮但它抛出了一个空参考例外。我是Android编程的新手，如果有人能够指出我在这里做错了什么，我将不胜感激。

Answer 1

您可以尝试这样做：

Button dialogbutton = dialog.FindViewById<Button>(Resource.Id.dialogButtonOK);

或者您可以使用标准（默认对话框）检查我的例子：

//make your dialog as global
Dialog alertDialog;

//your OnCreate() method
protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);


        SetContentView(Resource.Layout.Main);

        Button button = FindViewById<Button>(Resource.Id.MyButton);
        //now when you click on the button,dialog will appear with button OK(if you click on OK,dialog will disappear)
        button.Click += delegate {

            var builder = new AlertDialog.Builder(_context);
                        builder.SetTitle("Titolo");

                        builder.SetMessage("Test this example");
                        builder.SetCancelable(false);

                        builder.SetPositiveButton("OK", new EventHandler<DialogClickEventArgs>((sender1, e2) =>
                            { 
                                alertDialog.Dismiss();
                            }));
                        alertDialog = builder.Create();
                        alertDialog.SetCanceledOnTouchOutside(false);
                        alertDialog.Show();

        };
    }

享受！

自定义对话框内的按钮返回空引用异常

1 个答案: