利用WPF绘图

C#入门经典 25章的一个例子，利用WPF绘图。

XAML：

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        x:Class="Ch25Ex01.MainWindow"
        Title="Color Spinner" Height="370" Width="270">
    <Window.Resources>
        <Storyboard x:Key="Spin">
            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00"
                Storyboard.TargetName="ellipse1"
                Storyboard.TargetProperty=
   "(UIElement.RenderTransform).(TransformGroup.Children)[0].(RotateTransform.Angle)"    
                RepeatBehavior="Forever">
                <SplineDoubleKeyFrame KeyTime="00:00:10" Value="360"/>
            </DoubleAnimationUsingKeyFrames>
            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00"
                Storyboard.TargetName="ellipse2"
                Storyboard.TargetProperty=
    "(UIElement.RenderTransform).(TransformGroup.Children)[0].(RotateTransform.Angle)"   
                RepeatBehavior="Forever">
                <SplineDoubleKeyFrame KeyTime="00:00:10" Value="-360" />
            </DoubleAnimationUsingKeyFrames>
            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00"
                Storyboard.TargetName="ellipse3"
                Storyboard.TargetProperty=
    "(UIElement.RenderTransform).(TransformGroup.Children)[0].(RotateTransform.Angle)"   
                RepeatBehavior="Forever">
                <SplineDoubleKeyFrame KeyTime="00:00:05" Value="360" />
            </DoubleAnimationUsingKeyFrames>
            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00"
                Storyboard.TargetName="ellipse4"
                Storyboard.TargetProperty=
    "(UIElement.RenderTransform).(TransformGroup.Children)[0].(RotateTransform.Angle)"
                RepeatBehavior="Forever">
                <SplineDoubleKeyFrame KeyTime="00:00:05" Value="-360" />
            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
    </Window.Resources>
    <Window.Triggers>
        <EventTrigger RoutedEvent="FrameworkElement.Loaded">
            <BeginStoryboard Storyboard="{StaticResource Spin}"
                x:Name="Spin_BeginStoryBoard" />
        </EventTrigger>
        <EventTrigger RoutedEvent="ButtonBase.Click" SourceName="goButton" >
            <ResumeStoryboard BeginStoryboardName="Spin_BeginStoryBoard" />
        </EventTrigger>
        <EventTrigger RoutedEvent="ButtonBase.Click" SourceName="stopButton" >
            <PauseStoryboard BeginStoryboardName="Spin_BeginStoryBoard"/>
        </EventTrigger>
    </Window.Triggers>
    
    <Window.Background>
        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
            <GradientStop Color="#FFFFFFFF" Offset="0" />
            <GradientStop Color="#FFFFC45A" Offset="1" />
        </LinearGradientBrush>
    </Window.Background>
    
    <Grid>
        <Ellipse Margin="50,50,0,0" Name="ellipse5" Stroke="Black" Height="150"
            HorizontalAlignment="Left" VerticalAlignment="Top" Width="150">
            <Ellipse.Effect>
                <BlurEffect Radius="10" />
            </Ellipse.Effect>
            <Ellipse.Fill>
                <RadialGradientBrush>
                    <GradientStop Color="#FF000000" Offset="1" />
                    <GradientStop Color="#FFFFFFFF" Offset="0.306" />
                </RadialGradientBrush>
            </Ellipse.Fill>
        </Ellipse>
        <Ellipse Margin="15,85,0,0" Name="ellipse1" Stroke="{x:Null}"
            Height="80" HorizontalAlignment="Left" VerticalAlignment="Top" 
            Width="120" Fill="Red" Opacity="0.5" RenderTransformOrigin="0.92,0.5">
            <Ellipse.Effect>
                <BlurEffect />
            </Ellipse.Effect>
            <Ellipse.RenderTransform>
                <TransformGroup>
                    <RotateTransform Angle="0"/>
                </TransformGroup>
            </Ellipse.RenderTransform>
        </Ellipse>
        <Ellipse Margin="85,15,0,0" Name="ellipse2" Stroke="{x:Null}"
            Height="120" HorizontalAlignment="Left" VerticalAlignment="Top" 
            Width="80" Fill="Blue" Opacity="0.5" RenderTransformOrigin="0.5,0.92">
            <Ellipse.Effect>
                <BlurEffect />
            </Ellipse.Effect>
            <Ellipse.RenderTransform>
                <TransformGroup>
                    <RotateTransform Angle="0"/>
                </TransformGroup>
            </Ellipse.RenderTransform>
        </Ellipse>
        <Ellipse Margin="115,85,0,0" Name="ellipse3" Stroke="{x:Null}"
            Height="80" HorizontalAlignment="Left" VerticalAlignment="Top" 
            Width="120" Opacity="0.5" Fill="Yellow"
            RenderTransformOrigin="0.08,0.5">
            <Ellipse.Effect>
                <BlurEffect />
            </Ellipse.Effect>
            <Ellipse.RenderTransform>
                <TransformGroup>
                    <RotateTransform Angle="0"/>
                </TransformGroup>
            </Ellipse.RenderTransform>
        </Ellipse>
        <Ellipse Margin="85,115,0,0" Name="ellipse4" Stroke="{x:Null}"
            Height="120" HorizontalAlignment="Left" VerticalAlignment="Top" 
            Width="80" Opacity="0.5" Fill="Green"
            RenderTransformOrigin="0.5,0.08">
            <Ellipse.Effect>
                <BlurEffect />
            </Ellipse.Effect>
            <Ellipse.RenderTransform>
                <TransformGroup>
                    <RotateTransform Angle="0"/>
                </TransformGroup>
            </Ellipse.RenderTransform>
        </Ellipse>
        <Button Height="23" HorizontalAlignment="Left" Margin="20,0,0,56"
            Name="goButton" VerticalAlignment="Bottom" Width="75" Content="Go" />
        <Button Height="23" HorizontalAlignment="Left" Margin="152,0,0,56"
            Name="stopButton" VerticalAlignment="Bottom" Width="75" Content="Stop" />
        <Button Height="23" HorizontalAlignment="Left" Margin="85,0,86,16"
            Name="toggleButton" VerticalAlignment="Bottom" Width="75" Content="Toggle" Click="toggleButton_Click" />
    </Grid>
</Window>

交互逻辑：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Media.Animation;

namespace Ch25Ex01
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void toggleButton_Click(object sender, RoutedEventArgs e)
        {
            Storyboard spinStoryboard = Resources["Spin"] as Storyboard;
            if (spinStoryboard != null)
            {
                if (spinStoryboard.GetIsPaused(this))
                    spinStoryboard.Resume(this);
                else
                    spinStoryboard.Pause(this);
            }
        }
    }
}

最终效果很炫哦，推荐自己动手实现。