silverlight 对ChildWindow返回给父窗体值的理解

这篇文章是我对ChildWindow的理解，举例说明：

有时候在项目中需要弹出子窗体进行一些操作，然后将操作的值返回到父窗体中。

下图是子窗体的界面（比较粗糙。。。。）

下面贴出其代码：

子窗体前台代码

 1 <controls:ChildWindow x:Class="FineMmarketing.Controls.SelectChild"
 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="365" Height="226" 
 6            Title="请选择纬度">
 7     <Grid x:Name="LayoutRoot" Margin="2" >
 8         <Grid.RowDefinitions>
 9             <RowDefinition />
10             <RowDefinition Height="Auto" />
11         </Grid.RowDefinitions>
12         <StackPanel Margin="0,0,0,37">            
13             <TextBlock Width="100" Height="30" Text="请输入纬度：" Margin="83 35 0 0" HorizontalAlignment="Left" />
14             <TextBox x:Name="Txt" Width="200" Height="30" HorizontalAlignment="Center" Margin="24 0 0 0"/>
15         </StackPanel>
16         
17         <Button x:Name="CancelButton" Content="取消" Click="CancelButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,0,0" Grid.Row="1" />
18         <Button x:Name="OKButton" Content="确定" Click="OKButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,79,0" Grid.Row="1" />
19     </Grid>
20 </controls:ChildWindow>

子窗体后台代码

 1  /// <summary>
 2         /// 确定按钮
 3         /// </summary>
 4         /// <param name="sender"></param>
 5         /// <param name="e"></param>
 6         private void OKButton_Click(object sender, RoutedEventArgs e)
 7         {            
 8             if (!String.IsNullOrEmpty(this.Txt.Text))
 9             {
10                 Regex reg = new Regex("^[0-9]+$");
11                 Match ma = reg.Match(this.Txt.Text.ToString());
12                 if (ma.Success)
13                 {
14                     Num = Convert.ToInt32(this.Txt.Text.ToString());
15                     if (Num > 10)
16                     {
17                         MessageBox.Show("纬度不能超过10！");
18                         return;
19                     }
20                     else
21                     {
22                         this.Tag = Num;
23                     }           
24                 }
25                 else
26                 {
27                     MessageBox.Show("请输入正确的纬度！");
28                 }
29             }
30             else
31             {
32                 MessageBox.Show("请输入纬度！");
33             }
34             this.DialogResult = true;
35         }
36  /// <summary>
37         /// 取消按钮
38         /// </summary>
39         /// <param name="sender"></param>
40         /// <param name="e"></param>
41         private void CancelButton_Click(object sender, RoutedEventArgs e)
42         {
43             this.DialogResult = false;
44         }

然后看一下在父窗体中如何调用子窗体，然后后台定义事件执行子窗体关闭事件。

子窗体后台代码

 1 SelectChild myChild = new SelectChild();//申明子窗体对象
 2 ////定义子窗体关闭事件
 3 myChild.Closed += new EventHandler(win_Closed);
 4 
 5 
 6  /// <summary>
 7         /// 子窗口关闭返回值事件
 8         /// </summary>
 9         /// <param name="sender"></param>
10         /// <param name="e"></param>
11         void win_Closed(object sender,EventArgs e)
12         {
13             bool? result = myChild.DialogResult;
14             //判断是否是顶级确定按钮关闭并且有返回值
15             if (result.HasValue && result.Value)
16             {
17                 //是定义在子窗体中的公有的全局变量
18                 MessageBox.Show(myChild.txt);
19             }
20         }