How to create a custom OpenFiledialog Property for a UserControl - wpf

Question

When I right click a UserControl and select Properties, I want to create a custom property inside the UserControl properties that loads a file from an OpenFileDialog, like the ColumnDefinitions, but that browses inside my machine:
How can I achieve that? I've been searching but I'm a bit lost on where to start from.
NOTE: The image indicates that the property I want to create is one of the properties of the UserControl that appear when you Right click->Properties the UserControl.
Thanks!

Answer 1

I declared a property for searching execuble files in an OpenFileDialog in a WinForm project. The code is in VB .NET.
First create a Class like this:
Imports System.Drawing.Design
Imports System.Windows.Forms.Design
Imports System.Windows.Forms
Public Class ExecutableEditor : Inherits UITypeEditor
Public Overrides Function GetEditStyle(context As System.ComponentModel.ITypeDescriptorContext) As System.Drawing.Design.UITypeEditorEditStyle
Return UITypeEditorEditStyle.Modal
End Function
Public Overrides Function EditValue(context As System.ComponentModel.ITypeDescriptorContext, provider As System.IServiceProvider, value As Object) As Object
If context Is Nothing And context.Instance Is Nothing And provider Is Nothing Then
Return value
End If
Dim editor_service As IWindowsFormsEditorService = _
CType(provider.GetService(GetType(IWindowsFormsEditorService)), _
IWindowsFormsEditorService)
If editor_service Is Nothing Then Return value
Dim ofdEjecutable As New OpenFileDialog
ofdEjecutable.Title = "Select an executable file"
ofdEjecutable.FileName = Nothing
ofdEjecutable.Filter = "executable file|*.exe"
If ofdEjecutable.ShowDialog = DialogResult.OK Then
Return ofdEjecutable.FileName
Else
Return Nothing
End If
End Function
End Class
Then in the code of the UserControl declare a property like this:
Private _executable As String
<Category("Injection")> _
<EditorAttribute(GetType(ExecutableEditor), GetType(UITypeEditor))> _
Public Property Executable As String
Get
Return _executable
End Get
Set(value As String)
_executable = value
End Set
End Property

Answer 2

What I got from your question is that you want a Browsable Property for you user control. Going by this, for simple .net property add:
private string myString;
[Browsable(true)]
[Category("Other")]
public string MyProperty { get { return myString; } set { myString = value; } }
and in setter of the property load the file after validation.
If you want it to be dependancy property do the same but move the code of loading the file in the propertychange handler.