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WPF/MVVM - Generic Dialog With Return Value

Posted By:      Posted Date: September 23, 2010    Points: 0   Category :WPF

I'm trying to create a generic dialog in WPF using the MVVM pattern. The dialog's return value needs to be generic so it can return anything. In this case I want to return an instance of my DialogOptions class.

First, I created a DialogBase class that has a dependency property for the return value: 

using System;
using System.Windows;

namespace OutputCompare
  public class _DialogBase<T> : Window where T : new()
    public static readonly DependencyProperty RetValDP = DependencyProperty.Register("RetVal", typeof(T), typeof(_DialogBase<T>), new FrameworkPropertyMetadata());
    public T RetVal
      get { return (T)GetValue(RetValDP); }
        SetValue(RetValDP, value);

    public _DialogBase()
      RetVal = new T();
 Next I create a dialog based off it
<src:_DialogBase x:Class="OutputCompare.LoadDialog"
         RetVal="{Binding Option

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