WPF 动画

WPF的实现方式有多种，使用演示图板对属性进行动画处理、不使用演示图板对属性进行动画处理

这里分别记录两种操作方式

(1)使用演示图板对属性进行动画处理

<StackPanel Margin="30" HorizontalAlignment="Left" MinWidth="500">
            <TextBlock>Storyboard Animation Example</TextBlock>
            <!-- The width of this button is animated. -->
            <Button Content="A Button" Name="myWidthAnimatedButton" Height="30" Width="200" HorizontalAlignment="Left">
                <Button.Triggers>
                    <!-- Animates the width of the first button  from 200 to 300. -->
                    <EventTrigger RoutedEvent="Button.Click">
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation Storyboard.TargetName="myWidthAnimatedButton"
                                                 Storyboard.TargetProperty="Width"
                                                 From="200" To="300" Duration="0:0:3" />
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger>
                </Button.Triggers>
            </Button>

            <!-- The color of the brush used to paint this button is animated. -->
            <Button  Content="Another Button" Height="30" Width="200"   HorizontalAlignment="Left">
                <Button.Background>
                    <SolidColorBrush x:Name="myAnimatedBrush" Color="Blue" />
                </Button.Background>
                <Button.Triggers>
                    <!-- Animates the color of the brush used to paint the second button from red to blue . -->
                    <EventTrigger RoutedEvent="Button.Click">
                        <BeginStoryboard>
                            <Storyboard>
                                <ColorAnimation  Storyboard.TargetName="myAnimatedBrush"
                                                 Storyboard.TargetProperty="Color"
                                                 From="Red" To="Blue" Duration="0:0:7" />
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger>
                </Button.Triggers>
            </Button>
</StackPanel>

            this.Title = "Animate Properties using Storyboards";

            #region 容器
            //定义一个stackpanel作为容器
            StackPanel myStackPanel = new StackPanel();
            myStackPanel.MinWidth = 500;
            myStackPanel.Margin = new Thickness(30);
            myStackPanel.HorizontalAlignment = HorizontalAlignment.Left;

            //容器添加到当前窗体
            this.AddChild(myStackPanel); 
            #endregion

            #region 第一个按钮动画
            // 创建一个按钮
            Button myWidthAnimatedButton = new Button();
            myWidthAnimatedButton.Height = 30;
            myWidthAnimatedButton.Width = 200;
            myWidthAnimatedButton.HorizontalAlignment = HorizontalAlignment.Left;
            myWidthAnimatedButton.Content = "A Button";

            // Set the Name of the button so that it can be referred
            // to in the storyboard that's created later.
            // The ID doesn't have to match the variable name;
            // it can be any unique identifier.
            myWidthAnimatedButton.Name = "myWidthAnimatedButton";


            //Create a name scope for the Window
            NameScope.SetNameScope(this, new NameScope());
            // Register the name with the Window to which the button belongs.
            this.RegisterName(myWidthAnimatedButton.Name, myWidthAnimatedButton);

            // Create a DoubleAnimation to animate the width of the button.
            DoubleAnimation myDoubleAnimation = new DoubleAnimation();
            myDoubleAnimation.From = 200;
            myDoubleAnimation.To = 300;
            myDoubleAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(3000));

            // Configure the animation to target the button's Width property.
            Storyboard.SetTargetName(myDoubleAnimation, myWidthAnimatedButton.Name);
            Storyboard.SetTargetProperty(myDoubleAnimation, new PropertyPath(Button.WidthProperty));

            // Create a storyboard to contain the animation.
            Storyboard myWidthAnimatedButtonStoryboard = new Storyboard();
            myWidthAnimatedButtonStoryboard.Children.Add(myDoubleAnimation);

            // Animate the button width when it's clicked.
            myWidthAnimatedButton.Click += (sender, args) =>
                myWidthAnimatedButtonStoryboard.Begin(this);

            myStackPanel.Children.Add(myWidthAnimatedButton); 
            #endregion
            
            #region 第二个按钮动画
            // Create a second button.
            Button myColorAnimatedButton = new Button();
            myColorAnimatedButton.Height = 30;
            myColorAnimatedButton.Width = 200;
            myColorAnimatedButton.HorizontalAlignment = HorizontalAlignment.Left;
            myColorAnimatedButton.Content = "Another Button";

            // Create a SolidColorBrush to paint the button's background.
            SolidColorBrush myBackgroundBrush = new SolidColorBrush();
            myBackgroundBrush.Color = Colors.Blue;

            // Because a Brush isn't a FrameworkElement, it doesn't
            // have a Name property to set. Instead, you just
            // register a name for the SolidColorBrush with
            // the page where it's used.
            this.RegisterName("myAnimatedBrush", myBackgroundBrush);

            // Use the brush to paint the background of the button.
            myColorAnimatedButton.Background = myBackgroundBrush;

            // Create a ColorAnimation to animate the button's background.
            ColorAnimation myColorAnimation = new ColorAnimation();
            myColorAnimation.From = Colors.Red;
            myColorAnimation.To = Colors.Blue;
            myColorAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(7000));

            // Configure the animation to target the brush's Color property.
            Storyboard.SetTargetName(myColorAnimation, "myAnimatedBrush");
            Storyboard.SetTargetProperty(myColorAnimation, new PropertyPath(SolidColorBrush.ColorProperty));

            // Create a storyboard to contain the animation.
            Storyboard myColorAnimatedButtonStoryboard = new Storyboard();
            myColorAnimatedButtonStoryboard.Children.Add(myColorAnimation);

            // Animate the button background color when it's clicked.
            myColorAnimatedButton.Click += (sender, args) =>
                myColorAnimatedButtonStoryboard.Begin(myColorAnimatedButton);

            myStackPanel.Children.Add(myColorAnimatedButton); 
            #endregion        

后台代码方式比较麻烦，代码量比较大，但是更灵活，也更容易理解storyboard的工作方式

这里有两个地方纠结了很久，不清楚是干什么用的，结果删掉之后，提示"不存在可解析名称XXXX的适用名称领域"

            //Create a name scope for the Window
            NameScope.SetNameScope(this, new NameScope());
            // Register the name with the Window to which the button belongs.
            this.RegisterName(myWidthAnimatedButton.Name, myWidthAnimatedButton);        

原来我们在写

Storyboard.SetTargetName(myDoubleAnimation, myWidthAnimatedButton.Name);

的时候是通过元素名称映射元素对象的，我们定义完元素之后没有注册，执行myWidthAnimatedButtonStoryboard.Begin(this)的时候，

方法就找不到元素。NameScope类具体使用参考 这里

（2）在不使用演示图板的情况下对属性进行动画处理

            WindowTitle = "Local Animation Example";
            StackPanel myStackPanel = new StackPanel();
            myStackPanel.Margin = new Thickness(20);                     


            // Create and set the Button.
            Button aButton = new Button();
            aButton.Content = "A Button";

            // Animate the Button's Width.
            DoubleAnimation myDoubleAnimation = new DoubleAnimation();
            myDoubleAnimation.From = 75;
            myDoubleAnimation.To = 300;
            myDoubleAnimation.Duration =  new Duration(TimeSpan.FromSeconds(5));
            myDoubleAnimation.AutoReverse = true;
            myDoubleAnimation.RepeatBehavior = RepeatBehavior.Forever;

            // Apply the animation to the button's Width property.
            aButton.BeginAnimation(Button.WidthProperty, myDoubleAnimation);       

            // Create and animate a Brush to set the button's Background.
            SolidColorBrush myBrush = new SolidColorBrush();
            myBrush.Color = Colors.Blue;            

            ColorAnimation myColorAnimation = new ColorAnimation();
            myColorAnimation.From = Colors.Blue;
            myColorAnimation.To = Colors.Red;
            myColorAnimation.Duration =  new Duration(TimeSpan.FromMilliseconds(7000));
            myColorAnimation.AutoReverse = true;
            myColorAnimation.RepeatBehavior = RepeatBehavior.Forever;

            // Apply the animation to the brush's Color property.
            myBrush.BeginAnimation(SolidColorBrush.ColorProperty, myColorAnimation);           
            aButton.Background = myBrush;

            // Add the Button to the panel.
            myStackPanel.Children.Add(aButton);
            this.Content = myStackPanel;

同样可以实现，但是灵活性就降低了，例如不能更好的控制时间线、停止、暂停，不容易多个动画组合

参考 http://msdn.microsoft.com/zh-cn/library/ms752312%28v=vs.100%29.aspx

http://www.cnblogs.com/zhouyinhui/archive/2007/04/10/706107.html