巧用Delegate在Silverlight多个页面、控件中传递回调方法

在论坛中看到经常有人碰到如何在SilverLight多个页面或者控件中传替参数或者值的问题，今天抽空通过Delegate机制实现回调实例方法重设动画参数的DEMO,分享给大家。最终结果如图:

　　

在论坛中看到经常有人碰到如何在SilverLight多个页面或者控件中传替参数或者值的问题，今天抽空通过Delegate机制实现回调实例方法重设动画参数的DEMO,分享给大家。最终结果如图:

 

 

    演示地址:http://xingjunli.webs.com/DelegateDemo.html
    参考资料:动画概述：http://msdn.microsoft.com/zh-cn/library/cc189019(VS.95).aspx 委托：http://msdn.microsoft.com/zh-cn/library/900fyy8e.aspx
   1、初识委托:
      委托delegate有点类似于非托管C/C++中的函数指针，在C#中通过委托机制来回掉实例方法，静态方法等（更重要是委托为托管代码，能保证回调方法的类型的安全）
   2、使用委托回调实例方法:   
      2.1、用C#的delegate关键字来定义回掉函数的签名(本示例中我们通过一个单独的类来实义委托以提高重用):
 
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01./// <summary>   
02.        /// 声明delegate方法   
03.        /// </summary>   
04.        /// <param name="x"></param>   
05.        /// <param name="y"></param>   
06.        public delegate void delgateResetParentMethod(double x,double y);  
/// <summary>
        /// 声明delegate方法
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        public delegate void delgateResetParentMethod(double x,double y);  
     2.2、在子窗体类中我们定义一个委托类型对象如:
 
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01.public helper.delgateResetParentMethod CallBackMethod;  
public helper.delgateResetParentMethod CallBackMethod; 
     2.3、在父窗体中实例化子窗体时将实例方法传递给委托:
  
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01.UCDelegateChildWindow childWindow = new UCDelegateChildWindow();   
02.                childWindow.CallBackMethod = ReaplayAnimation;   
UCDelegateChildWindow childWindow = new UCDelegateChildWindow();
                childWindow.CallBackMethod = ReaplayAnimation; 
 

     2.4、用我们熟悉的方法调用语法来调用回掉函数:

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01.    if (this.DialogResult.Value && CallBackMethod != null)   
02.    {   
03.this.CallBackMethod(Double.Parse(txtX.Text), Double.Parse(txtY.Text));   
04.this.Close();   
05.    }  
      if (this.DialogResult.Value && CallBackMethod != null)
      {
  this.CallBackMethod(Double.Parse(txtX.Text), Double.Parse(txtY.Text));
  this.Close();
      }
 

     3、上面我们应用委托实现了最简单的应用，实际工作中会复杂的多；我们的编译器和CLR为我们做了大量幕后工作以减轻使用的复杂性;如需了解更多请参考:委托（C# 编程指南）http://msdn.microsoft.com/zh-cn/library/ms173171.aspx
   实现步骤(附源代码):
     声明委托类型：

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01.public class helper   
02.{   
03.       /// <summary>   
04.       /// 声明delegate方法   
05.       /// </summary>   
06.       /// <param name="x"></param>   
07.       /// <param name="y"></param>   
08.       public delegate void delgateResetParentMethod(double x,double y);   
09.}  
 public class helper
 {
        /// <summary>
        /// 声明delegate方法
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        public delegate void delgateResetParentMethod(double x,double y);
 } 
    子窗体XAML：

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01.<controls:ChildWindow x:Class="LoadSilverlight.UCDelegateChildWindow"  
02.           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
03.           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    
04.           xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"  
05.           Width="200" Height="170"    
06.           Title="重设动画坐标:">   
07.    <Grid x:Name="LayoutRoot" Margin="2">   
08.        <Grid.RowDefinitions>   
09.            <RowDefinition />   
10.            <RowDefinition Height="Auto" />   
11.        </Grid.RowDefinitions>   
12.        <Canvas Grid.Row="0" Grid.Column="0" Margin="1">   
13.            <Canvas.Background>   
14.                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">   
15.                    <GradientStop Color="#E6E0F3F4" Offset="0"/>   
16.                    <GradientStop Color="#FFB3BDC7" Offset="1"/>   
17.                </LinearGradientBrush>   
18.            </Canvas.Background>   
19.            <TextBlock Text="X:" Canvas.Left="11" Canvas.Top="8" />   
20.            <TextBox x:Name="txtX" Canvas.Left="28" Canvas.Top="8" Width="140" Text="100" />   
21.                <TextBlock Text="Y:" Canvas.Left="12" Canvas.Top="46" RenderTransformOrigin="0.417,1.375" />   
22.            <TextBox x:Name="txtY" Canvas.Left="28" Canvas.Top="44" Width="140" Text="100"/>   
23.        </Canvas>   
24.            <Button x:Name="CancelButton" Content="Cancel" Click="CancelButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,0,0" Grid.Row="1" />   
25.        <Button x:Name="OKButton" Content="OK" Click="OKButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,79,0" Grid.Row="1" />   
26.    </Grid>   
27.</controls:ChildWindow>  
<controls:ChildWindow x:Class="LoadSilverlight.UCDelegateChildWindow"
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
           xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"
           Width="200" Height="170" 
           Title="重设动画坐标:">
    <Grid x:Name="LayoutRoot" Margin="2">
        <Grid.RowDefinitions>
            <RowDefinition />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <Canvas Grid.Row="0" Grid.Column="0" Margin="1">
         <Canvas.Background>
          <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
           <GradientStop Color="#E6E0F3F4" Offset="0"/>
           <GradientStop Color="#FFB3BDC7" Offset="1"/>
          </LinearGradientBrush>
         </Canvas.Background>
            <TextBlock Text="X:" Canvas.Left="11" Canvas.Top="8" />
            <TextBox x:Name="txtX" Canvas.Left="28" Canvas.Top="8" Width="140" Text="100" />
                <TextBlock Text="Y:" Canvas.Left="12" Canvas.Top="46" RenderTransformOrigin="0.417,1.375" />
            <TextBox x:Name="txtY" Canvas.Left="28" Canvas.Top="44" Width="140" Text="100"/>
        </Canvas>
            <Button x:Name="CancelButton" Content="Cancel" Click="CancelButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,0,0" Grid.Row="1" />
        <Button x:Name="OKButton" Content="OK" Click="OKButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,79,0" Grid.Row="1" />
    </Grid>
</controls:ChildWindow> 
    子窗体CS:

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01.using System;   
02.using System.Collections.Generic;   
03.using System.Linq;   
04.using System.Net;   
05.using System.Windows;   
06.using System.Windows.Controls;   
07.using System.Windows.Documents;   
08.using System.Windows.Input;   
09.using System.Windows.Media;   
10.using System.Windows.Media.Animation;   
11.using System.Windows.Shapes;   
12.  
13.namespace LoadSilverlight   
14.{   
15.    public partial class UCDelegateChildWindow : ChildWindow   
16.    {   
17.        public UCDelegateChildWindow()   
18.        {   
19.            InitializeComponent();   
20.        }   
21.  
22.        private void OKButton_Click(object sender, RoutedEventArgs e)   
23.        {   
24.            this.DialogResult = true;   
25.            if (this.DialogResult.Value && CallBackMethod != null)   
26.            {   
27.                this.CallBackMethod(Double.Parse(txtX.Text), Double.Parse(txtY.Text));   
28.                this.Close();   
29.            }   
30.              
31.        }   
32.  
33.        private void CancelButton_Click(object sender, RoutedEventArgs e)   
34.        {   
35.            this.DialogResult = false;   
36.        }   
37.  
38.        //定义页面委托对象   
39.        public helper.delgateResetParentMethod CallBackMethod;   
40.           
41.    }   
42.}  
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace LoadSilverlight
{
    public partial class UCDelegateChildWindow : ChildWindow
    {
        public UCDelegateChildWindow()
        {
            InitializeComponent();
        }

        private void OKButton_Click(object sender, RoutedEventArgs e)
        {
            this.DialogResult = true;
            if (this.DialogResult.Value && CallBackMethod != null)
            {
                this.CallBackMethod(Double.Parse(txtX.Text), Double.Parse(txtY.Text));
                this.Close();
            }
           
        }

        private void CancelButton_Click(object sender, RoutedEventArgs e)
        {
            this.DialogResult = false;
        }

        //定义页面委托对象
        public helper.delgateResetParentMethod CallBackMethod;
        
    }
}

 
    父窗体XAML:

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01.<UserControl x:Class="LoadSilverlight.UCDelegateParent"  
02.    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
03.    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Background="#FF333333" Foreground="{x:Null}">   
04.    <UserControl.Resources>   
05.        <Storyboard x:Name="sbRun">   
06.            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.X)">   
07.                <EasingDoubleKeyFrame KeyTime="00:00:00" Value="0"/>   
08.                <EasingDoubleKeyFrame KeyTime="00:00:06" Value="200">   
09.                    <EasingDoubleKeyFrame.EasingFunction>   
10.                        <ElasticEase EasingMode="EaseOut"/>   
11.                    </EasingDoubleKeyFrame.EasingFunction>   
12.                </EasingDoubleKeyFrame>   
13.            </DoubleAnimationUsingKeyFrames>   
14.            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.Y)">   
15.                <EasingDoubleKeyFrame KeyTime="00:00:00" Value="0"/>   
16.                <EasingDoubleKeyFrame KeyTime="00:00:06" Value="200">   
17.                    <EasingDoubleKeyFrame.EasingFunction>   
18.                        <ElasticEase EasingMode="EaseOut"/>   
19.                    </EasingDoubleKeyFrame.EasingFunction>   
20.                </EasingDoubleKeyFrame>   
21.            </DoubleAnimationUsingKeyFrames>   
22.        </Storyboard>   
23.    </UserControl.Resources>   
24.    <Grid x:Name="LayoutRoot" Background="#FF424242">   
25.        <Ellipse x:Name="ellipse" Height="64" HorizontalAlignment="Left" Margin="25,32,0,0" VerticalAlignment="Top" Width="64" RenderTransformOrigin="0.5,0.5">   
26.            <Ellipse.RenderTransform>   
27.                <TransformGroup>   
28.                    <ScaleTransform/>   
29.                    <SkewTransform/>   
30.                    <RotateTransform/>   
31.                    <TranslateTransform x:Name="ellipseTrans"/>   
32.                </TransformGroup>   
33.            </Ellipse.RenderTransform>   
34.            <Ellipse.Fill>   
35.                <RadialGradientBrush RadiusX="0.559" RadiusY="0.559">   
36.                    <GradientStop Color="#FFFF0606"/>   
37.                    <GradientStop Color="#72702525" Offset="0.717"/>   
38.                    <GradientStop Color="#00702525" Offset="1"/>   
39.                </RadialGradientBrush>   
40.            </Ellipse.Fill>   
41.        </Ellipse>   
42.        <Button x:Name="btnReset" Height="33" HorizontalAlignment="Right" Margin="0,0,8,8" VerticalAlignment="Bottom" Width="100" Content="重设坐标" FontFamily="微软雅黑" FontWeight="Bold" FontSize="18.667"/>   
43.        <HyperlinkButton HorizontalAlignment="Right" Margin="8,0,116,15" VerticalAlignment="Bottom" Content="http://Blog.csdn.net/xingjunli" NavigateUri="http://Blog.csdn.net/xingjunli" FontStyle="Italic"/>   
44.           
45.    </Grid>   
46.</UserControl>  
<UserControl x:Class="LoadSilverlight.UCDelegateParent"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Background="#FF333333" Foreground="{x:Null}">
 <UserControl.Resources>
  <Storyboard x:Name="sbRun">
   <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.X)">
    <EasingDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
    <EasingDoubleKeyFrame KeyTime="00:00:06" Value="200">
     <EasingDoubleKeyFrame.EasingFunction>
      <ElasticEase EasingMode="EaseOut"/>
     </EasingDoubleKeyFrame.EasingFunction>
    </EasingDoubleKeyFrame>
   </DoubleAnimationUsingKeyFrames>
   <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.Y)">
    <EasingDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
    <EasingDoubleKeyFrame KeyTime="00:00:06" Value="200">
     <EasingDoubleKeyFrame.EasingFunction>
      <ElasticEase EasingMode="EaseOut"/>
     </EasingDoubleKeyFrame.EasingFunction>
    </EasingDoubleKeyFrame>
   </DoubleAnimationUsingKeyFrames>
  </Storyboard>
 </UserControl.Resources>
    <Grid x:Name="LayoutRoot" Background="#FF424242">
     <Ellipse x:Name="ellipse" Height="64" HorizontalAlignment="Left" Margin="25,32,0,0" VerticalAlignment="Top" Width="64" RenderTransformOrigin="0.5,0.5">
      <Ellipse.RenderTransform>
       <TransformGroup>
        <ScaleTransform/>
        <SkewTransform/>
        <RotateTransform/>
        <TranslateTransform x:Name="ellipseTrans"/>
       </TransformGroup>
      </Ellipse.RenderTransform>
      <Ellipse.Fill>
       <RadialGradientBrush RadiusX="0.559" RadiusY="0.559">
        <GradientStop Color="#FFFF0606"/>
        <GradientStop Color="#72702525" Offset="0.717"/>
        <GradientStop Color="#00702525" Offset="1"/>
       </RadialGradientBrush>
      </Ellipse.Fill>
     </Ellipse>
     <Button x:Name="btnReset" Height="33" HorizontalAlignment="Right" Margin="0,0,8,8" VerticalAlignment="Bottom" Width="100" Content="重设坐标" FontFamily="微软雅黑" FontWeight="Bold" FontSize="18.667"/>
     <HyperlinkButton HorizontalAlignment="Right" Margin="8,0,116,15" VerticalAlignment="Bottom" Content="http://Blog.csdn.net/xingjunli" NavigateUri="http://Blog.csdn.net/xingjunli" FontStyle="Italic"/>
     
    </Grid>
</UserControl>
 
    父窗体CS:

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01.using System;   
02.using System.Collections.Generic;   
03.using System.Linq;   
04.using System.Net;   
05.using System.Windows;   
06.using System.Windows.Controls;   
07.using System.Windows.Documents;   
08.using System.Windows.Input;   
09.using System.Windows.Media;   
10.using System.Windows.Media.Animation;   
11.using System.Windows.Shapes;   
12.  
13.namespace LoadSilverlight   
14.{   
15.    public partial class UCDelegateParent : UserControl   
16.    {   
17.        UCDelegateChildWindow childWindow;   
18.        public UCDelegateParent()   
19.        {   
20.            InitializeComponent();   
21.            btnReset.Click += new RoutedEventHandler(btnReset_Click);   
22.            sbRun.Completed += new EventHandler(sbRun_Completed);   
23.            this.Loaded += new RoutedEventHandler(UCDelegateParent_Loaded);   
24.        }   
25.  
26.        void UCDelegateParent_Loaded(object sender, RoutedEventArgs e)   
27.        {   
28.            sbRun.Begin();   
29.        }   
30.  
31.        void sbRun_Completed(object sender, EventArgs e)   
32.        {   
33.            ShowChildWindow();   
34.        }   
35.  
36.        void btnReset_Click(object sender, RoutedEventArgs e)   
37.        {   
38.            ShowChildWindow();   
39.        }   
40.        private void ShowChildWindow()   
41.        {   
42.            if (childWindow == null)   
43.            {   
44.                childWindow = new UCDelegateChildWindow();   
45.                childWindow.CallBackMethod = ReaplayAnimation; //为子窗体(可以是任意窗体或者控件)注册父窗体实例方法(这里的参数类型和个数必须匹配)   
46.            }   
47.            childWindow.Show();   
48.        }   
49.  
50.        //父窗体重设动画属性播放动画   
51.        private void ReaplayAnimation(double x,double y)   
52.        {   
53.  
54.            DoubleAnimationUsingKeyFrames framsX = sbRun.Children[0] as DoubleAnimationUsingKeyFrames;   
55.            DoubleAnimationUsingKeyFrames framsY = sbRun.Children[1] as DoubleAnimationUsingKeyFrames;   
56.               
57.            framsX.KeyFrames[0].Value = framsX.KeyFrames[1].Value;   
58.            framsX.KeyFrames[1].Value = x;   
59.            framsY.KeyFrames[0].Value = framsY.KeyFrames[1].Value;   
60.            framsY.KeyFrames[1].Value = y;   
61.               
62.            sbRun.Stop();   
63.            sbRun.Begin();   
64.        }   
65.    }   
66.}  
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace LoadSilverlight
{
    public partial class UCDelegateParent : UserControl
    {
        UCDelegateChildWindow childWindow;
        public UCDelegateParent()
        {
            InitializeComponent();
            btnReset.Click += new RoutedEventHandler(btnReset_Click);
            sbRun.Completed += new EventHandler(sbRun_Completed);
            this.Loaded += new RoutedEventHandler(UCDelegateParent_Loaded);
        }

        void UCDelegateParent_Loaded(object sender, RoutedEventArgs e)
        {
            sbRun.Begin();
        }

        void sbRun_Completed(object sender, EventArgs e)
        {
            ShowChildWindow();
        }

        void btnReset_Click(object sender, RoutedEventArgs e)
        {
            ShowChildWindow();
        }
        private void ShowChildWindow()
        {
            if (childWindow == null)
            {
                childWindow = new UCDelegateChildWindow();
                childWindow.CallBackMethod = ReaplayAnimation; //为子窗体(可以是任意窗体或者控件)注册父窗体实例方法(这里的参数类型和个数必须匹配)
            }
            childWindow.Show();
        }

        //父窗体重设动画属性播放动画
        private void ReaplayAnimation(double x,double y)
        {

            DoubleAnimationUsingKeyFrames framsX = sbRun.Children[0] as DoubleAnimationUsingKeyFrames;
            DoubleAnimationUsingKeyFrames framsY = sbRun.Children[1] as DoubleAnimationUsingKeyFrames;
            
            framsX.KeyFrames[0].Value = framsX.KeyFrames[1].Value;
            framsX.KeyFrames[1].Value = x;
            framsY.KeyFrames[0].Value = framsY.KeyFrames[1].Value;
            framsY.KeyFrames[1].Value = y;
            
            sbRun.Stop();
            sbRun.Begin();
        }
    }
}
 
  结束语:SilverLight同.Net FrameWork本身已经很好的结合起来，C#中一些实用的编程机制(如：委托)，在SL中合理运用，将给我们带来意想不到的收获!