WPF and Silverlight 学习笔记（六）：WPF窗体

一、窗体类

在Visual Studio和Expression Blend中，自定义的窗体均继承System.Windows.Window类（类型化窗体）。定义的窗体由两部分组成：

1、XAML文件

   1: <Window

   2:     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

   3:     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

   4:     x:Class="WpfWindow.BasicWindow"

   5:     x:Name="Window"

   6:     Title="BasicWindow"

   7:     Width="300" Height="200">

   8:     <Canvas>

   9:         <Button x:Name="btnMessage" Width="79" Height="24" Content="OK" 

  10:         Canvas.Left="172" Canvas.Top="93" Click="btnMessage_Click"/>

  11:         <TextBox x:Name="txtValue" Width="215" Height="25" 

  12:         Canvas.Left="36" Canvas.Top="48" Text="" TextWrapping="Wrap"/>

  13:     </Canvas>

  14: </Window>

2、后台代码文件

   1: using System;

   2: using System.Windows;

   3:  

   4: namespace WpfWindow

   5: {

   6:     public partial class BasicWindow : Window

   7:     {

   8:         public BasicWindow()

   9:         {

  10:             this.InitializeComponent();

  11:         }

  12:  

  13:         private void btnMessage_Click(object sender, System.Windows.RoutedEventArgs e)

  14:         {

  15:             txtValue.Text = "Hello World";

  16:         }

  17:     }

  18: }

也可以将后台代码放在XAML文件中，上面的例子可以改写为：

   1: <Window

   2:     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

   3:     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

   4:     x:Class="WpfWindow.BasicWindow"

   5:     x:Name="Window"

   6:     Title="BasicWindow"

   7:     Width="300" Height="200">

   8:     <Canvas>

   9:         <Button x:Name="btnMessage" Width="79" Height="24" Content="OK" 

  10:         Canvas.Left="172" Canvas.Top="93" Click="btnMessage_Click"/>

  11:         <x:Code><![CDATA[

  12:             void btnMessage_Click(object sender, System.Windows.RoutedEventArgs e)

  13:             {

  14:                 txtValue.Text = "Hello World";

  15:             }

  16:         ]]>

  17:         </x:Code>

  18:         <TextBox x:Name="txtValue" Width="215" Height="25" 

  19:         Canvas.Left="36" Canvas.Top="48" Text="" TextWrapping="Wrap"/>

  20:     </Canvas>

  21: </Window>

 

二、窗体的生存周期

1、显示窗体

• 构造方法
• Show()、ShowDialog()方法：Show()方法显示非模态窗口，ShowDialog()方法显示模态窗口
• Loaded事件：窗体第一次Show()或ShowDialog()时引发的事件，通常在此事件中加载窗体的初始化数据

2、关闭窗体

• Close()方法：关闭窗体，并释放窗体的资源
• Closing事件、Closed事件：关闭时、关闭后引发的事件，通常在Closing事件中提示用户是否退出。

3、窗体的激活

• Activate()方法：激活某窗体
• Activated、Deactivated事件：当窗体激动、失去焦点时引发的事件

4、窗体的生存周期

示例程序：

• 在窗体载入时显示当前日期，并开始播放媒体
• 当窗体失去焦点时暂停播放媒体
• 当窗体重新获得焦点时继承播放窗体
• 当点击窗体的关闭按钮时，询问用户是否退出应用程序

XAML文件：

   1: <Window x:Class="WpfWindow.WindowLifeCycle"

   2:     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

   3:     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

   4:     Title="WindowLifeCycle" Height="200" Width="300" 

   5:         Loaded="Window_Loaded" 

   6:         Activated="Window_Activated" 

   7:         Deactivated="Window_Deactivated" 

   8:         Closing="Window_Closing">

   9:     <Canvas>

  10:         <TextBlock Canvas.Right="15" Canvas.Bottom="15" Height="21" Name="txtDate"/>

  11:         <MediaElement Canvas.Left="89" Canvas.Top="12" Height="100" Width="100" 

  12:                       Name="myMedia" Source="numbers.wmv" 

  13:                       Stretch="Fill" LoadedBehavior="Manual" />

  14:     </Canvas>

  15: </Window>

代码文件：

 

   1: using System;

   2: using System.Windows;

   3:  

   4: namespace WpfWindow

   5: {

   6:     public partial class WindowLifeCycle : Window

   7:     {

   8:         public WindowLifeCycle()

   9:         {

  10:             InitializeComponent();

  11:         }

  12:  

  13:         // 开关变量，判断是否正在播放媒体

  14:         private bool isPlaying;

  15:  

  16:         private void Window_Loaded(object sender, RoutedEventArgs e)

  17:         {

  18:             // 窗体加载时，显示当前日期及开始播放媒体

  19:             txtDate.Text = DateTime.Now.ToString("yyyy-MM-dd");

  20:  

  21:             myMedia.Play();

  22:             isPlaying = true;

  23:         }

  24:  

  25:         private void Window_Activated(object sender, EventArgs e)

  26:         {

  27:             // 如果窗体被激活，则继承播放媒体

  28:             if (!isPlaying)

  29:             {

  30:                 myMedia.Play();

  31:                 isPlaying = true;

  32:             }

  33:         }

  34:  

  35:         private void Window_Deactivated(object sender, EventArgs e)

  36:         {

  37:             // 如果窗体失去焦点，则暂停播放媒体

  38:             if (isPlaying)

  39:             {

  40:                 myMedia.Pause();

  41:                 isPlaying = false;

  42:             }

  43:         }

  44:  

  45:         private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)

  46:         {

  47:             // 点击窗体的“关闭”按钮，询问用户是否退出程序

  48:  

  49:             string message = "Quit the application?";

  50:             string title = "System Information";

  51:             MessageBoxButton button = MessageBoxButton.OKCancel;

  52:             MessageBoxImage img = MessageBoxImage.Question;

  53:  

  54:             MessageBoxResult result = MessageBox.Show(

  55:                 message, title, button, img);

  56:  

  57:             if (result == MessageBoxResult.Cancel)

  58:             {

  59:                 e.Cancel = true;    // 取消退出

  60:             }

  61:         }

  62:     }

  63: }

 

三、其他窗体相关的属性、方法、事件

WPF窗体的详细的属性、方法、事件请参考MSDN，有很多的属性、方法、事件与Windows应用程序中System.Windows.Forms.Form类相同或近似，其中常用的一些属性、方法、事件有：

• 窗体边框模式（WindowStyle属性）和是否允许更改窗体大小（ResizeMode属性）
• 窗体启动位置（WindowStartupLocation属性）和启动状态（WindowState属性）
• 窗体标题（Title属性）
• 始终在最前（TopMost属性）
• 是否显示在任务栏（ShowInTaskbar）

四、定义异形窗体

使用异形窗体，可以将窗体的背景设置为透明，边框设置为空，然后利用控件做出异形的窗体，例如：

XAML：

   1: <Window x:Class="WpfWindow.CustomerWindow"

   2:     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

   3:     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

   4:     Title="NonRectangularWindowSample" SizeToContent="WidthAndHeight" 

   5:     MouseLeftButtonDown="NonRectangularWindow_MouseLeftButtonDown"

   6:     WindowStyle="None" 

   7:     AllowsTransparency="True" 

   8:     Background="Transparent">

   9:     <Canvas Width="200" Height="200" >

  10:         <Path Stroke="DarkGray" StrokeThickness="2">

  11:             <Path.Fill>

  12:                 <LinearGradientBrush StartPoint="0.2,0" EndPoint="0.8,1" >

  13:                     <GradientStop Color="White"  Offset="0"></GradientStop>

  14:                     <GradientStop Color="White"  Offset="0.45"></GradientStop>

  15:                     <GradientStop Color="LightBlue" Offset="0.9"></GradientStop>

  16:                     <GradientStop Color="Gray" Offset="1"></GradientStop>

  17:                 </LinearGradientBrush>

  18:             </Path.Fill>

  19:             <Path.Data>

  20:                 <PathGeometry>

  21:                     <PathFigure StartPoint="40,20" IsClosed="True">

  22:                         <LineSegment Point="160,20"></LineSegment>

  23:                         <ArcSegment Point="180,40" Size="20,20" SweepDirection="Clockwise"></ArcSegment>

  24:                         <LineSegment Point="180,80"></LineSegment>

  25:                         <ArcSegment Point="160,100" Size="20,20" SweepDirection="Clockwise"></ArcSegment>

  26:                         <LineSegment Point="90,100"></LineSegment>

  27:                         <LineSegment Point="90,150"></LineSegment>

  28:                         <LineSegment Point="60,100"></LineSegment>

  29:                         <LineSegment Point="40,100"></LineSegment>

  30:                         <ArcSegment Point="20,80" Size="20,20" SweepDirection="Clockwise"></ArcSegment>

  31:                         <LineSegment Point="20,40"></LineSegment>

  32:                         <ArcSegment Point="40,20" Size="20,20" SweepDirection="Clockwise"></ArcSegment>

  33:                     </PathFigure>

  34:                 </PathGeometry>

  35:             </Path.Data>

  36:         </Path>

  37:         <Label Width="200" Height="120" FontSize="15" HorizontalContentAlignment="Center" VerticalContentAlignment="Center">Drag Me</Label>

  38:         <Button Canvas.Left="155" Canvas.Top="30" Click="closeButtonRectangle_Click">

  39:             <Button.Template>

  40:                 <ControlTemplate>

  41:                     <Canvas>

  42:                         <Rectangle Width="15" Height="15" Stroke="Black" RadiusX="3" RadiusY="3">

  43:                             <Rectangle.Fill>

  44:                                 <SolidColorBrush x:Name="myAnimatedBrush" Color="Red" />

  45:                             </Rectangle.Fill>

  46:                         </Rectangle>

  47:                         <Line X1="3" Y1="3" X2="12" Y2="12" Stroke="White" StrokeThickness="2"></Line>

  48:                         <Line X1="12" Y1="3" X2="3" Y2="12" Stroke="White" StrokeThickness="2"></Line>

  49:                     </Canvas>

  50:                 </ControlTemplate>

  51:             </Button.Template>

  52:         </Button>

  53:     </Canvas>

  54: </Window>

代码文件：

   1: using System.Windows;

   2: using System.Windows.Input;

   3:  

   4: namespace WpfWindow

   5: {

   6:     public partial class CustomerWindow : Window

   7:     {

   8:         public CustomerWindow()

   9:         {

  10:             InitializeComponent();

  11:         }

  12:  

  13:         void NonRectangularWindow_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)

  14:         {

  15:             this.DragMove();

  16:         }

  17:  

  18:         void closeButtonRectangle_Click(object sender, RoutedEventArgs e)

  19:         {

  20:             this.Close();

  21:         }

  22:     }

  23: }

 

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