在開發WPF的專案時，有時候可能會礙于平臺的限制或是使用的語言及類別庫的限制，部份功能還是得透過Windows Form來或是某些Windows Form控制項來實作，可是整個系統的外觀已經是既定的WPF了，那要怎么把Windows Form整合進來呢??

　　首先，得引用WindowsFormsIntegration.dll(若使用.Net Framework 4.0版的話，預設路徑在C:\Windows\Microsoft.NET\Framework\v4.0.30319\WPF)，以及System.Windows.Forms，接著就可以在WPF中透過WindowsFormsHost這個元件來承載Windows Form的控制項了!!

　　來寫個小小的範例：

　　MainWindow.xaml

1: <Window x:Class="WPF_Winform.MainWindow"
2: xmlns="//schemas.microsoft.com/winfx/2006/xaml/presentation"
3: xmlns:x="//schemas.microsoft.com/winfx/2006/xaml"
4: xmlns:mc="//schemas.openxmlformats.org/markup-compatibility/2006"
5: xmlns:d="//schemas.microsoft.com/expression/blend/2008"
6: xmlns:WinFormHost="clr-namespace:System.Windows.Forms.Integration;assembly=WindowsFormsIntegration"
7: xmlns:WinFormControls="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms"
8: mc:Ignorable="d"
9: Title="MainWindow"
10: d:DesignWidth="800" d:DesignHeight="600"
11: Width="Auto" Height="Auto">
12: <Grid>
13: <WinFormHost:WindowsFormsHost Name="winFormHost">
14: <WinFormControls:FlowLayoutPanel Name="floPanel" BackColor="Transparent">
15: <WinFormControls:FlowLayoutPanel.Controls>
16: <WinFormControls:Label Text="WinformLabel"/>
17: <WinFormControls:TextBox Width="200"/>
18: <WinFormControls:Button Text="WinformButton" Width="150"/>
19: </WinFormControls:FlowLayoutPanel.Controls>
20: </WinFormControls:FlowLayoutPanel>
21: </WinFormHost:WindowsFormsHost>
22: </Grid>
23: </Window>

　　那~能不能在這邊的Windows Form控制項裡面再放WPF控制項呢?答案是可以的!!透過ElementHost控制項就可以辦到啰，而且我們也可以直接在XAML中分別替Windows Form和WPF的按鈕元件加入Click的EventHandler喔!!

我們來修改一下MainWindow.xaml

1: <Window x:Class="WPF_Winform.MainWindow"
2: xmlns="//schemas.microsoft.com/winfx/2006/xaml/presentation"
3: xmlns:x="//schemas.microsoft.com/winfx/2006/xaml"
4: xmlns:mc="//schemas.openxmlformats.org/markup-compatibility/2006"
5: xmlns:d="//schemas.microsoft.com/expression/blend/2008"
6: xmlns:WinFormHost="clr-namespace:System.Windows.Forms.Integration;assembly=WindowsFormsIntegration"
7: xmlns:WinFormControls="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms"
8: mc:Ignorable="d"
9: Title="MainWindow"
10: d:DesignWidth="800" d:DesignHeight="600"
11: Width="Auto" Height="Auto">
12: <Grid Background="Gray">
13: <WinFormHost:WindowsFormsHost Name="winFormHost" VerticalAlignment="Center" HorizontalAlignment="Center" Background="White">
14: <WinFormControls:FlowLayoutPanel Name="floPanel" BackColor="Transparent">
15: <WinFormControls:FlowLayoutPanel.Controls>
16: <WinFormControls:Label Text="WinformLabel"/>
17: <WinFormControls:TextBox Width="200"/>
18: <WinFormControls:Button Text="WinformButton" Width="150" Click="Button_Click"/>
19: <ElementHost Height="200" Width="200">
20: <Grid Height="200" Width="200" VerticalAlignment="Center" HorizontalAlignment="Center" Background="Yellow">
21: <Button Content="WPF Button" Width="150" Height="40" Click="Button_Click"/>
22: </Grid>
23: </ElementHost>
24: </WinFormControls:FlowLayoutPanel.Controls>
25: </WinFormControls:FlowLayoutPanel>
26: </WinFormHost:WindowsFormsHost>
27: </Grid>

還有MainWindow.xaml.cs，Windows Form和WPF的Button產生出來的Click EventHandler長相不一樣喔!!

1: using System.Windows;
2:
3: namespace WPF_Winform
4: {
5: public partial class MainWindow : Window
6: {
7: public MainWindow()
8: {
9: InitializeComponent();
10: }
11:
12: private void Button_Click( object sender , System.EventArgs e )
13: {
14: MessageBox.Show("你點了Winform的按鈕");
15: }
16:
17: private void Button_Click( object sender , RoutedEventArgs e )
18: {
19: MessageBox.Show( "你點了WPF的按鈕" );
20: }
21: }
22: }　　

執行結果會變這樣：

　　不過要注意一點，尤于Render機制不同的關係，若是想要把WPF的控制項覆蓋在WindowsFormsHost控制項之上的話，是做不到的喔!!WindowsFormsHost塬生就會具有類似AlwaysOnTop的效果。