Create a Client-Side UI Automation Provider

This topic contains example code that shows how to implement a client-side UI Automation provider.

Example

The following example code can be built into a dynamic-link library (DLL) that implements a very simple client-side provider for a console window. The code does not have any useful functionality, but is intended to demonstrate the basic steps in setting up a provider assembly that can be registered by a UI Automation client application.

using System;
using System.Windows.Automation;
using System.Windows.Automation.Provider;

namespace ClientSideProviderAssembly
{
 // The assembly must implement a UIAutomationClientSideProviders class,
 // and the namespace must be the same as the name of the DLL, so that
 // UI Automation can find the table of descriptors. In this example,
 // the DLL would be "ClientSideProviderAssembly.dll"

 static class UIAutomationClientSideProviders
 {
 /// <summary>
 /// Implementation of the static ClientSideProviderDescriptionTable field.
 /// In this case, only a single provider is listed in the table.
 /// </summary>
 public static ClientSideProviderDescription[] ClientSideProviderDescriptionTable =
 {
 new ClientSideProviderDescription(
 // Method that creates the provider object.
 new ClientSideProviderFactoryCallback(ConsoleProvider.Create),
 // Class of window that will be served by the provider.
 "ConsoleWindowClass")
 };
 }

 class ConsoleProvider : IRawElementProviderSimple
 {
 IntPtr providerHwnd;

 public ConsoleProvider(IntPtr hwnd)
 {
 providerHwnd = hwnd;
 }

 internal static IRawElementProviderSimple Create(
 IntPtr hwnd, int idChild, int idObject)
 {
 // This provider doesn't expose children, so never expects
 // nonzero values for idChild.
 if (idChild != 0)
 return null;
 else
 return new ConsoleProvider(hwnd);
 }

 private static IRawElementProviderSimple Create(
 IntPtr hwnd, int idChild)
 {
 // Something is wrong if idChild is not 0.
 if (idChild != 0) return null;
 else return new ConsoleProvider(hwnd);
 }

 #region IRawElementProviderSimple

 // This is a skeleton implementation. The only real functionality
 // at this stage is to return the name of the element and the host
 // window provider, which can supply other properties.

 ProviderOptions IRawElementProviderSimple.ProviderOptions
 {
 get
 {
 return ProviderOptions.ClientSideProvider;
 }
 }

 IRawElementProviderSimple IRawElementProviderSimple.HostRawElementProvider
 {
 get
 {
 return AutomationInteropProvider.HostProviderFromHandle(providerHwnd);
 }
 }

 object IRawElementProviderSimple.GetPropertyValue(int propertyId)
 {
 if (propertyId == AutomationElementIdentifiers.NameProperty.Id)
 return "Custom Console Window";
 else
 return null;
 }

 object IRawElementProviderSimple.GetPatternProvider(int iid)
 {
 return null;
 }
 #endregion IRawElementProviderSimple
 }
}

Imports System.Windows.Automation
Imports System.Windows.Automation.Provider

Namespace ClientSideProviderAssembly
 ' The assembly must implement a UIAutomationClientSideProviders class, 
 ' and the namespace must be the same as the name of the DLL, so that 
 ' UI Automation can find the table of descriptors. In this example, 
 ' the DLL would be "ClientSideProviderAssembly.dll"

 Friend NotInheritable Class UIAutomationClientSideProviders
 ''' <summary>
 ''' Implementation of the static ClientSideProviderDescriptionTable field. 
 ''' In this case, only a single provider is listed in the table.
 ''' </summary>
 Public Shared ClientSideProviderDescriptionTable() As ClientSideProviderDescription = { New ClientSideProviderDescription(New ClientSideProviderFactoryCallback(AddressOf ConsoleProvider.Create), "ConsoleWindowClass") }
 ' Method that creates the provider object.
 ' Class of window that will be served by the provider.
 End Class

 Friend Class ConsoleProvider
 Implements IRawElementProviderSimple
 Private providerHwnd As IntPtr

 Public Sub New(ByVal hwnd As IntPtr)
 providerHwnd = hwnd
 End Sub

 Friend Shared Function Create(ByVal hwnd As IntPtr, ByVal idChild As Integer, ByVal idObject As Integer) As IRawElementProviderSimple
 ' This provider doesn't expose children, so never expects 
 ' nonzero values for idChild.
 If idChild <> 0 Then
 Return Nothing
 Else
 Return New ConsoleProvider(hwnd)
 End If

 End Function

 Private Shared Function Create(ByVal hwnd As IntPtr, ByVal idChild As Integer) As IRawElementProviderSimple
 ' Something is wrong if idChild is not 0.
 If idChild <> 0 Then
 Return Nothing
 Else
 Return New ConsoleProvider(hwnd)
 End If
 End Function

 #Region "IRawElementProviderSimple"

 ' This is a skeleton implementation. The only real functionality 
 ' at this stage is to return the name of the element and the host 
 ' window provider, which can supply other properties.

 Private ReadOnly Property IRawElementProviderSimple_ProviderOptions() As ProviderOptions Implements IRawElementProviderSimple.ProviderOptions
 Get
 Return ProviderOptions.ClientSideProvider
 End Get
 End Property

 Private ReadOnly Property HostRawElementProvider() As IRawElementProviderSimple Implements IRawElementProviderSimple.HostRawElementProvider
 Get
 Return AutomationInteropProvider.HostProviderFromHandle(providerHwnd)
 End Get
 End Property

 Private Function GetPropertyValue(ByVal propertyId As Integer) As Object Implements IRawElementProviderSimple.GetPropertyValue
 If propertyId = AutomationElementIdentifiers.NameProperty.Id Then
 Return "Custom Console Window"
 Else
 Return Nothing
 End If

 End Function

 Private Function GetPatternProvider(ByVal iid As Integer) As Object Implements IRawElementProviderSimple.GetPatternProvider
 Return Nothing
 End Function
 #End Region ' IRawElementProviderSimple
 End Class
End Namespace

See also

• UI Automation Providers Overview
• Register a Client-Side Provider Assembly