c# 怎么得到窗口中控件的句柄

c# 如何得到窗口中控件的句柄
[img=http://][/img]我本人是搞C++的，C#的有些不太熟，
下面是一个简单的对话框的XAML，里面有个canvas和button1变量，我想得到这两个的句柄(HWND)

<Window x:Class="Traffic.AP.FocusSet"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        Title="调焦设置" FontSize="16" Height="500" Width="500" WindowStartupLocation="CenterScreen" ResizeMode="CanMinimize" Closing="Window_Closing" Loaded="Window_Loaded">

    <Grid>

        <Grid.RowDefinitions>

            <RowDefinition Height="370*" />

            <RowDefinition Height="91*" />

        </Grid.RowDefinitions>

        <Canvas Name="canvas" Grid.Row="0">

        </Canvas>

        <Button Content="抓拍" Grid.Row="1" Height="28" HorizontalAlignment="Left" Margin="147,22,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />

    </Grid>

</Window>

类的代码如下，

namespace Traffic.AP

{

    /// <summary>

    /// Interaction logic for FocusSet.xaml

    /// </summary>

    public partial class FocusSet : Window

    {

        public FocusSet(delegateRecordFocus recordFocus,delegateGrabImg grabImg)

        {

            InitializeComponent();

            this.m_recordFocus = recordFocus;

            this.m_grabImg = grabImg;

        }


        public delegate void delegateRecordFocus(IntPtr hWndScreen, string tempDir, bool bStop);

        private delegateRecordFocus m_recordFocus;


        public delegate void delegateGrabImg();

        private delegateGrabImg m_grabImg;


        private void button1_Click(object sender, RoutedEventArgs e)

        {

            m_grabImg();

        }


        private void Window_Loaded(object sender, RoutedEventArgs e)

        {

            //var helper = new System.Windows.Interop.WindowInteropHelper(this);

            //IntPtr hWnd = helper.Handle;


            // 这里想获取canvs和button1的变量，不知道怎么获取，求指点