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稳扎稳打Silverlight(13) - 2.0交互之鼠标事件和键盘事件

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稳扎稳打Silverlight(13) - 2.0交互之鼠标事件和键盘事件


作者: webabcd


介绍
Silverlight 2.0 人机交互:响应用户的鼠标操作和键盘操作
    MouseEnter - 鼠标进入时触发的事件(显然,此事件不能冒泡)
    MouseLeave - 鼠标离开时触发的事件(显然,此事件不能冒泡)
    MouseLeftButtonDown - 鼠标左键单击按下时触发的事件
    MouseLeftButtonUp - 鼠标左键单击按下并放开时触发的事件
    MouseMove - 鼠标移动时触发的事件
    MouseEventArgs.GetPosition() - 鼠标相对于指定元素的坐标
    MouseButtonEventArgs.Handled - 此事件是否已被处理
    KeyDown - 鼠标按下时触发的事件
    KeyUp - 鼠标按下并放开时触发的事件
    KeyEventArgs.Key - 与事件相关的键盘的按键 [System.Windows.Input.Key枚举]
    KeyEventArgs.Handled - 是否处理过此事件
    System.Windows.Input.Keyboard.Modifiers - 当前按下的辅助键 [System.Windows.Input.ModifierKeys枚举]


在线DEMO
http://www.voidcn.com/article/p-ounmxjds-tq.html  


示例
1、Mouse.xaml
<UserControl x:Class="Silverlight20.Interactive.Mouse"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
        
        <!--路由事件是一种可以针对元素树中的多个侦听器(而不是仅针对引发该事件的对象)调用处理程序的事件-->
        
        <!--
        MouseLeftButtonDown,MouseLeftButtonUp和MouseMove均为向上冒泡的路由事件
        本例的事件路由为:Ellipse -> StackPanel -> UserControl 或 Rectangle -> Canvas -> StackPanel -> UserControl
        如果不想向上冒泡,则可以使用 MouseButtonEventArgs.Handled = true 告知事件已被处理
        -->
        <StackPanel HorizontalAlignment="Left" MouseLeftButtonDown="StackPanel_MouseLeftButtonDown" >

                <!--
                MouseEnter - 鼠标进入时触发的事件(显然,此事件不能冒泡)
                MouseLeave - 鼠标离开时触发的事件(显然,此事件不能冒泡)
                
                MouseLeftButtonDown - 鼠标左键单击按下时触发的事件
                MouseLeftButtonUp - 鼠标左键单击按下并放开时触发的事件
                MouseMove - 鼠标移动时触发的事件
                -->
                <Ellipse x:Name="ellipse" Width="200" Height="100" Fill="Red" Margin="5"    
                        MouseEnter="ellipse_MouseEnter"    
                        MouseLeave="ellipse_MouseLeave"
                        MouseLeftButtonDown="ellipse_MouseLeftButtonDown"
                        MouseLeftButtonUp="ellipse_MouseLeftButtonUp"
                >
                </Ellipse>

                <Canvas Margin="5">

                        <!--用于演示拖放的矩形-->
                        <Rectangle x:Name="rectangle" Fill="Blue" Width="50" Height="50"
                                MouseLeftButtonDown="rectangle_MouseLeftButtonDown"
                                MouseLeftButtonUp="rectangle_MouseLeftButtonUp"
                                MouseMove="rectangle_MouseMove"
                        />
                        
                </Canvas>

        </StackPanel>
</UserControl>
 
Mouse.xaml.cs

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 Silverlight20.Interactive

{

         public partial class Mouse : UserControl

        {

                 public Mouse()

                {

                        InitializeComponent();

                }


                 void ellipse_MouseEnter( object sender,MouseEventArgs e)

                {

                        ellipse.Fill = new SolidColorBrush(Colors.Yellow);

                }


                 void ellipse_MouseLeave( object sender,MouseEventArgs e)

                {

                        ellipse.Fill = new SolidColorBrush(Colors.Red);

                }


                 private void ellipse_MouseLeftButtonUp( object sender,MouseButtonEventArgs e)

                {

                        ellipse.Fill = new SolidColorBrush(Colors.Yellow);

                }


                 private void ellipse_MouseLeftButtonDown( object sender,MouseButtonEventArgs e)

                {

                        ellipse.Fill = new SolidColorBrush(Colors.Blue);


                         // MouseButtonEventArgs.Handled - 此事件是否已被处理

                         //         false - 未被处理,事件的路由为向上冒泡

                         //         true - 已被处理,事件的路由为不再冒泡

                        e.Handled = true;

                }


                 private void StackPanel_MouseLeftButtonDown( object sender,MouseButtonEventArgs e)

                {

                         // 如果鼠标单击 rectangle 对象,则 会 执行到此句

                         // 如果鼠标单击 ellipse 对象,则 不会 执行到此句,因为之前 ellipse 对象的 MouseLeftButtonDown 事件中已经设置 e.Handled = true ,所以事件不会冒泡至此

                        ellipse.Fill = new SolidColorBrush(Colors.Black);

                }

                



                 // 是否正在捕获鼠标

                 private bool _isMouseCaptured;


                 // 鼠标垂直方向上的坐标

                 private double _mouseY;


                 // 鼠标水平方向上的坐标

                 private double _mouseX;


                 private void rectangle_MouseLeftButtonDown( object sender,MouseButtonEventArgs e)

                {

                         // MouseButtonEventArgs.GetPosition() - 鼠标相对于指定元素的坐标

                        _mouseY = e.GetPosition( null).Y;

                        _mouseX = e.GetPosition( null).X;


                         // CaptureMouse() - 在指定的元素上捕获鼠标

                        rectangle.CaptureMouse();

                        _isMouseCaptured = true;

                }


                 public void rectangle_MouseMove( object sender,MouseEventArgs e)

                {

                         if (_isMouseCaptured)

                        {

                                 // 移动前和移动后的鼠标 垂直方向 和 水平方向 的位置的差值

                                 double v = e.GetPosition( null).Y - _mouseY;

                                 double h = e.GetPosition( null).X - _mouseX;


                                 // 移动后的 rectangle 对象相对于 Canvas 的坐标

                                 double newTop = v + ( double)rectangle.GetValue(Canvas.TopProperty);

                                 double newLeft = h + ( double)rectangle.GetValue(Canvas.LeftProperty);


                                 // 设置 rectangle 对象的位置为新的坐标.

                                rectangle.SetValue(Canvas.TopProperty,newTop);

                                rectangle.SetValue(Canvas.LeftProperty,newLeft);


                                 // 更新鼠标的当前坐标

                                _mouseY = e.GetPosition( null).Y;

                                _mouseX = e.GetPosition( null).X;

                        }

                }


                 private void rectangle_MouseLeftButtonUp( object sender,MouseButtonEventArgs e)

                {

                         // ReleaseMouseCapture() - 如果指定的元素具有鼠标捕获,则释放该捕获

                        rectangle.ReleaseMouseCapture();

                        _isMouseCaptured = false;

                }

        }

}
 
 
2、Keyboard.xaml
<!--
KeyDown - 鼠标按下时触发的事件
KeyUp - 鼠标按下并放开时触发的事件
-->
<!--
KeyDown和KeyUp均为向上冒泡的路由事件,本例的事件路由为:TextBox -> Canvas -> UserControl
-->
<UserControl x:Class="Silverlight20.Interactive.Keyboard"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    
        x:Name="userControl"
        KeyDown="userControl_KeyDown">
        
        <Canvas>
                        
                <TextBox x:Name="textBox" Text="TextBox" />
                
        </Canvas>
        
</UserControl>
 
Keyboard.xaml.cs

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 Silverlight20.Interactive

{

         public partial class Keyboard : UserControl

        {

                 public Keyboard()

                {

                        InitializeComponent();


                         this.Loaded += new RoutedEventHandler(Keyboard_Loaded);


                         // 为 UserControl 注册 KeyUp 事件

                        userControl.KeyUp += new KeyEventHandler(userControl_KeyUp);

                }


                 void Keyboard_Loaded( object sender,RoutedEventArgs e)

                {

                         // 让 UserControl 获得焦点,这样该 UserControl 内的元素才能监听到键盘事件

                        userControl.Focus();

                }


                 private void userControl_KeyDown( object sender,KeyEventArgs e)

                {

                         // 获取 textBox 对象的相对于 Canvas 的 x坐标 和 y坐标

                         double x = ( double)textBox.GetValue(Canvas.LeftProperty);

                         double y = ( double)textBox.GetValue(Canvas.TopProperty);


                         // KeyEventArgs.Key - 与事件相关的键盘的按键 [System.Windows.Input.Key枚举]

                         switch (e.Key)

                        {

                                 // 按 Up 键后 textBox 对象向 上 移动 1 个像素

                                 // Up 键所对应的 e.PlatformKeyCode == 38    

                                 // 当获得的 e.Key == Key.UnkNown 时,可以使用 e.PlatformKeyCode 来确定用户所按的键

                                 case Key.Up:

                                        textBox.SetValue(Canvas.TopProperty,y - 1);

                                         break;


                                 // 按 Down 键后 textBox 对象向 下 移动 1 个像素

                                 // Down 键所对应的 e.PlatformKeyCode == 40

                                 case Key.Down:

                                        textBox.SetValue(Canvas.TopProperty,y + 1);

                                         break;


                                 // 按 Left 键后 textBox 对象向 左 移动 1 个像素

                                 // Left 键所对应的 e.PlatformKeyCode == 37

                                 case Key.Left:

                                        textBox.SetValue(Canvas.LeftProperty,x - 1);

                                         break;


                                 // 按 Right 键后 textBox 对象向 右 移动 1 个像素

                                 // Right 键所对应的 e.PlatformKeyCode == 39    

                                 case Key.Right:

                                        textBox.SetValue(Canvas.LeftProperty,x + 1);

                                         break;


                                 default:

                                         break;

                        }


                         // 同上:Key.W - 向上移动; Key.S - 向下移动; Key.A - 向左移动; Key.D - 向右移动

                         switch (e.Key)

                        {

                                 // KeyEventArgs.Handled - 是否处理过此事件


                                 // 如果在文本框内敲 W ,那么文本框会向上移动,而且文本框内也会被输入 W

                                 // 如果只想移动文本框,而不输入 W ,那么可以设置 KeyEventArgs.Handled = true 告知此事件已经被处理完毕

                                 case Key.W:

                                        textBox.SetValue(Canvas.TopProperty,y - 1);

                                        e.Handled = true;

                                         break;

                                 case Key.S:

                                        textBox.SetValue(Canvas.TopProperty,y + 1);

                                        e.Handled = true;

                                         break;

                                 case Key.A:

                                        textBox.SetValue(Canvas.LeftProperty,x - 1);

                                        e.Handled = true;

                                         break;

                                 case Key.D:

                                        textBox.SetValue(Canvas.LeftProperty,x + 1);

                                        e.Handled = true;

                                         break;

                                 default:

                                         break;

                        }

                }


                 private void userControl_KeyUp( object sender,KeyEventArgs e)

                {

                         /*

                        System.Windows.Input.Keyboard.Modifiers - 当前按下的辅助键 [System.Windows.Input.ModifierKeys枚举]

                                ModifierKeys.None - 无

                                ModifierKeys.Alt - Alt 键

                                ModifierKeys.Control - Ctrl 键

                                ModifierKeys.Shift - Shift 键

                                ModifierKeys.Windows - Windows 键

                                ModifierKeys.Apple - Apple 键(苹果电脑)

                        */


                         // 按 Ctrl + M 则将 textBox 的位置设置为其初始位置

                         if (System.Windows.Input.Keyboard.Modifiers == ModifierKeys.Control && e.Key == Key.M)

                        {

                                textBox.SetValue(Canvas.LeftProperty,0d);

                                textBox.SetValue(Canvas.TopProperty,0d);

                        }

                }

        }

}
 
 

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