Silverlight 2動態建立矩形對象(附完整原始碼)

Silverlight 2動態建立矩形對象(附完整原始碼)[轉]

使用Silverlight 2的Canvas,寫了一個動態建立Rectangle的樣本,由於時間的原因所以難免有些不足之處,但程式功能都正常使用.用滑鼠可以點擊畫布任何位置拖出一個矩形對象,鬆開滑鼠即可完成一個矩形的建立!

程式運行效果:

 

XAML代碼:

1. <UserControl x:Class="Sample.dragrect"
2.     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
3.     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
4.     Width="780" Height="400">
5.     <StackPanel Background="Green" 
6.                 Orientation="Horizontal">
7.         <Canvas x:Name="LayoutRoot"
8.                 Background="GreenYellow"
9.                 Width="650" Height="400"
10.                 MouseMove="Canvas_MouseMove"
11.                 MouseLeftButtonDown="Canvas_MouseLeftButtonDown" 
12.                 MouseLeftButtonUp="Canvas_MouseLeftButtonUp"/>
13.         <StackPanel Background="Gold" Margin="10">
14.             <TextBlock Text="選擇顏色："/>
15.             <Button x:Name="btnRed" 
16.                     Width="100" Height="50" 
17.                     FontSize="20" Content="Red" Margin="5" 
18.                     Click="btnRed_Click"/>
19.             <Button x:Name="btnBlue" 
20.                     Width="100" Height="50"
21.                     FontSize="20" Content="Blue" Margin="5" 
22.                     Click="btnBlue_Click"/>
23.             <Button x:Name="btnGreen" 
24.                     Width="100" Height="50"
25.                     FontSize="20" Content="Green" Margin="5"
26.                     Click="btnGreen_Click"/>
27.             <Button x:Name="btnClear" 
28.                     Width="100" Height="50"
29.                     FontSize="20" Content="Clear" Margin="5" 
30.                     Background="Red"
31.                     Click="btnClear_Click"/>
32.         </StackPanel>
33.     </StackPanel>
34. </UserControl>

C#代碼:

1. using System;
2. using System.Collections.Generic;
3. using System.Linq;
4. using System.Net;
5. using System.Windows;
6. using System.Windows.Controls;
7. using System.Windows.Documents;
8. using System.Windows.Input;
9. using System.Windows.Media;
10. using System.Windows.Media.Animation;
11. using System.Windows.Shapes;
13. namespace Sample
14. {
15.     public partial class dragrect : UserControl
16.     {
17.         public dragrect()
18.         {
19.             InitializeComponent();
20.         }
22.         bool mouseMoveing = false;
23.         Point mousePoint;
24.         Color rectColor = Colors.Red;
26.         private void Canvas_MouseMove(object sender, MouseEventArgs e)
27.         {
28.             //如果滑鼠沒有拖動矩形則返回
29.             if (!mouseMoveing)
30.                 return;
31.             //擷取滑鼠當前座標
32.             Point curPos = e.GetPosition(null);
33.             //取得最小座標值
34.             double posX = mousePoint.X;
35.             double posY = mousePoint.Y;
36.             //計算矩形的寬和高
37.             double rectWidth = Math.Abs(curPos.X - mousePoint.X);
38.             double rectHeight = Math.Abs(curPos.Y - mousePoint.Y);
39.             //建立一個矩形元素
40.             Rectangle rect = new Rectangle();
41.             //聲明矩形的寬和高
42.             rect.Width = rectWidth;
43.             rect.Height = rectHeight;
44.             //填充顏色
45.             rect.Fill = new SolidColorBrush(rectColor);
46.             //聲明矩形在Canvas中建立的位置
47.             Canvas.SetLeft(rect, posX);
48.             Canvas.SetTop(rect, posY);
49.             //添加矩形到Canvas中
50.             LayoutRoot.Children.Add(rect);
51.         }
53.         private void Canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
54.         {
55.             //擷取當前的滑鼠位置
56.             mousePoint = e.GetPosition(null);
57.             //開始建立矩形
58.             mouseMoveing = true;
59.         }
61.         private void Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
62.         {
63.             //矩形建立完成
64.             mouseMoveing = false;
65.         }
67.         private void btnRed_Click(object sender, RoutedEventArgs e)
68.         {
69.             //聲明矩形顏色為Red
70.             rectColor = Colors.Red;
71.         }
73.         private void btnBlue_Click(object sender, RoutedEventArgs e)
74.         {
75.             //聲明矩形顏色為Blue
76.             rectColor = Colors.Blue;
77.         }
79.         private void btnGreen_Click(object sender, RoutedEventArgs e)
80.         {
81.             //聲明矩形顏色為Green
82.             rectColor = Colors.Green;
83.         }
85.         private void btnClear_Click(object sender, RoutedEventArgs e)
86.         {
87.             //清除所有Canvas內的矩形元素
88.             LayoutRoot.Children.Clear();
89.         }
90.     }
91. }