Show a Dialog using DialogFragment in Xamarin Android

Let us first define the layout for your fragment. In this example, I have used two TextViews and Button. My layout looks as follows:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="10dp">
    <TextView
        android:text="Lorem ipsum"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/textView1" />
    <TextView
        android:text="Lorem ipsum dolor sit amet, consectetuer adipiscing elit...."
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/textView2"
        android:layout_marginTop="10dp" />
    <Button
        android:text="Close"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/CloseButton"
        android:layout_marginTop="10dp" />
</LinearLayout>

Now let us inflate the layout from OnCreateView() method. My DialogFragment class looks as follows:

public class DialogFragment1 : DialogFragment
	{
		public static DialogFragment1 NewInstance(Bundle bundle){
			DialogFragment1 fragment = new DialogFragment1 ();
			fragment.Arguments = bundle;
			return fragment;
		}

		public override View OnCreateView (LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
		{
			// Use this to return your custom view for this Fragment
			View view =  inflater.Inflate(Resource.Layout.DialogFragment1Layout, container, false);
			Button button = view.FindViewById<Button> (Resource.Id.CloseButton);
			button.Click += delegate {
				Dismiss();
				Toast.MakeText(Activity ,"Dialog fragment dismissed!" , ToastLength.Short).Show();
			};

			return view;
		}
	}

We are pretty much done!. Add the following code snippet in your Activity to instantiate and display the dialog:
FragmentTransaction ft = FragmentManager.BeginTransaction();
//Remove fragment else it will crash as it is already added to backstack
Fragment prev = FragmentManager.FindFragmentByTag("dialog");
if (prev != null) {
	ft.Remove(prev);
}

ft.AddToBackStack(null);

// Create and show the dialog.
DialogFragment1 newFragment = DialogFragment1.NewInstance(null);

//Add fragment
newFragment.Show(ft, "dialog");

References :
http://javatechig.com/xamarin/alertdialog-and-dialogfragment-example-in-xamarin-android