在企业级项目中，子窗口(ChildWindow)是一个常用控件，其展示方式是以弹出窗口来显示信息。 这里我将演示，子窗口传递参数到父窗口的方法。由于我的开发环境都是英文环境，所以部分中文可能显示不正常，请大家见谅。
private ChildWindowDemo childWindowDemo = new ChildWindowDemo();
我们的目的是希望用户在子窗口输入一串文字，然后点击提交后，字符串将被返回显示在父窗口。
1. 首先创建一个新项目 “SLChildWindow",
2. 然后在新项目中,右键点击添加，添加一个新项目，选择“子窗口”（ChildWindow), 改名为"ChildWindowDemo.xaml",添加完成后，在子窗口中添加一个文本框，名为 txtUserInfo,
1<controls:ChildWindow x:Class="SLChildWindow.ChildWindowDemo"
2 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
3 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
4 xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"
5 Width="400" Height="300"
6 Title="ChildWindowDemo">
7 <Grid x:Name="LayoutRoot" Margin="2">
8 <Grid.RowDefinitions>
9 <RowDefinition />
10 <RowDefinition Height="Auto" />
11 </Grid.RowDefinitions>
12
13 <TextBox x:Name="txtUserInfor" Grid.Row="0" />
14
15 <Button x:Name="CancelButton" Content="Cancel" Click="CancelButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,0,0" Grid.Row="1" />
16 <Button x:Name="OKButton" Content="OK" Click="OKButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,79,0" Grid.Row="1" />
17 </Grid>
18</controls:ChildWindow>
<controls:ChildWindow x:Class="SLChildWindow.ChildWindowDemo"2
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4
xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"5
Width="400" Height="300" 6
Title="ChildWindowDemo">7
<Grid x:Name="LayoutRoot" Margin="2">8
<Grid.RowDefinitions>9
<RowDefinition />10
<RowDefinition Height="Auto" />11
</Grid.RowDefinitions>12
13
<TextBox x:Name="txtUserInfor" Grid.Row="0" />14
15
<Button x:Name="CancelButton" Content="Cancel" Click="CancelButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,0,0" Grid.Row="1" />16
<Button x:Name="OKButton" Content="OK" Click="OKButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,79,0" Grid.Row="1" />17
</Grid>18
</controls:ChildWindow>3. 在子窗口后台代码中创建一个字符串类型的属性，该属性将用来保存用户输入的字符串，
1 string testString;
2
3 public string TestString
4
5
{
6
7
get {return testString;}
8
9 set { testString = value; }
10
11
}
12
string testString;2
3
public string TestString4
5
{
6
7
get {return testString;}
8
9
set { testString = value; }10
11
} 12
4. 在子窗口中，建立一个EventHandler，父窗口将用该事件控制器获取子窗口参数，
1public event EventHandler OkClicked;
public event EventHandler OkClicked;5. 当前，在子窗口有两个按钮，一个是Ok按钮，一个是Cancel按钮，后台有两个按钮事件OKButton_Click，CancelButton_Click； 在OKButton_Click中调用前面我们定义的时间控制器OkClicked，
1 private void OKButton_Click(object sender, RoutedEventArgs e)
2 {
3 if (OkClicked != null)
4 {
5 TestString = txtUserInfor.Text;
6 OkClicked(this, new EventArgs());
7
}
8 this.DialogResult = true;
9 }
private void OKButton_Click(object sender, RoutedEventArgs e)2
{3
if (OkClicked != null)4
{5
TestString = txtUserInfor.Text;6
OkClicked(this, new EventArgs());7
}8
this.DialogResult = true;9
}6. 在父窗口MainPage.xaml中建立一个子窗口的实例，方便父窗口调用子窗口，
private ChildWindowDemo childWindowDemo = new ChildWindowDemo();7. 在父窗口MainPage.xaml中调用子窗口的OkClicked事件，
1 public MainPage()
2 {
3 InitializeComponent();
4 childWindowDemo.OkClicked += new EventHandler(childWindowDemo_OkClicked);
5 }
6
7 private void childWindowDemo_OkClicked(object sender, EventArgs e)
8 {
9 tbInfo.Text = childWindowDemo.TestString;
10 }
11
12 private void btPopup_Click(object sender, RoutedEventArgs e)
13 {
14 childWindowDemo.Show();
15 }
16
public MainPage()2
{3
InitializeComponent();4
childWindowDemo.OkClicked += new EventHandler(childWindowDemo_OkClicked);5
}6
7
private void childWindowDemo_OkClicked(object sender, EventArgs e)8
{9
tbInfo.Text = childWindowDemo.TestString;10
}11
12
private void btPopup_Click(object sender, RoutedEventArgs e)13
{14
childWindowDemo.Show();15
}16
8. 最后通过子窗口属性获取子窗口用户输入信息。
