WPF 基础到企业应用系列4——WPF千年轮回

1.开篇前言

2.本文提纲

3.Application

一.介绍

二.创建WPF应用程序

usingSystem;
usingSystem.Collections.Generic;
usingSystem.Configuration;
usingSystem.Data;
usingSystem.Linq;
usingSystem.Windows;

namespaceWPFApplications
{
///<summary>
///InteractionlogicforApp.xaml
///</summary>
publicpartialclassApp:Application
{
[STAThread]
staticvoidMain()
{
//定义Application对象作为整个应用程序入口
Applicationapp=newApplication();
//方法一：调用Run方法，参数为启动的窗体对象，也是最常用的方法
Window2win=newWindow2();
app.Run(win);

//方法二：指定Application对象的MainWindow属性为启动窗体，然后调用无参数的Run方法
//Window2win=newWindow2();
//app.MainWindow=win;
//win.Show();
//win.Show()是必须的，否则无法显示窗体
//app.Run();

//方法三：通过Url的方式启动
//app.StartupUri=newUri("Window2.xaml",UriKind.Relative);
//app.Run();
}
}
}

三、Application应用程序关闭

<Applicationx:Class="WPFApplications.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="Window2.xaml"
ShutdownMode="OnExplicitShutdown">
<Application.Resources>
</Application.Resources>
</Application>

四、Application对象的事件

<Applicationx:Class="WPFApplications.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="Window1.xaml"
Startup="Application_Startup"
Exit="Application_Exit"
DispatcherUnhandledException="Application_DispatcherUnhandledException">
<Application.Resources>

</Application.Resources>
</Application>

publicpartialclassApp:Application
{
[STAThread]
staticvoidMain()
{
//定义Application对象作为整个应用程序入口
Applicationapp=newApplication();
//方法一：调用Run方法，参数为启动的窗体对象，也是最常用的方法
Window2win=newWindow2();
app.Run(win);
}

privatevoidApplication_DispatcherUnhandledException(objectsender,System.Windows.Threading.
DispatcherUnhandledExceptionEventArgse)
{

}

privatevoidApplication_Exit(objectsender,ExitEventArgse)
{
}
}

publicpartialclassApp:Application
{
[STAThread]
staticvoidMain()
{
//定义Application对象作为整个应用程序入口
Applicationapp=newApplication();
//调用Run方法，参数为启动的窗体对象，也是最常用的方法
Window2win=newWindow2();
app.Startup+=newStartupEventHandler(app_Startup);
app.DispatcherUnhandledException+=newSystem.Windows.Threading.
DispatcherUnhandledExceptionEventHandler(app_DispatcherUnhandledException);
app.Run(win);
}

staticvoidapp_DispatcherUnhandledException(objectsender,System.Windows.Threading.
DispatcherUnhandledExceptionEventArgse)
{
thrownewNotImplementedException();
}

staticvoidapp_Startup(objectsender,StartupEventArgse)
{
thrownewNotImplementedException();
}
}

如果通过XAML启动窗体的话，也会编译成为为如下的程序，默认路径为Debug文件夹得App.g.cs文件：

publicpartialclassApp:System.Windows.Application{

///<summary>
///InitializeComponent
///</summary>
[System.Diagnostics.DebuggerNonUserCodeAttribute()]
publicvoidInitializeComponent(){

#line4"..\..\App.xaml"
this.StartupUri=newSystem.Uri("Window5.xaml",System.UriKind.Relative);

#linedefault
#linehidden
}

///<summary>
///ApplicationEntryPoint.
///</summary>
[System.STAThreadAttribute()]
[System.Diagnostics.DebuggerNonUserCodeAttribute()]
publicstaticvoidMain(){
WPFApplications.Appapp=newWPFApplications.App();
app.InitializeComponent();
app.Run();
}
}

五、WPF应用程序生存周期

2、后台代码文件

namespaceWPFApplications
{
///<summary>
///InteractionlogicforWindow5.xaml
///</summary>
publicpartialclassWindow5:Window
{
publicWindow5()
{
InitializeComponent();
}

privatevoidbtnOK_Click(objectsender,RoutedEventArgse)
{
lblHello.Content="HelloWorldChanged";
}
}
}

<Windowx:Class="WPFApplications.Window5"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window5"Height="300"Width="300">
<StackPanel>
<Labelx:Name="lblHello">Hello,World!</Label>
<Buttonx:Name="btnOK"Width="88"Height="22"Content="Click"
Click="btnOK_Click"/>
<x:Code>
<![CDATA[
voidbtnOK_Click(objectsender,System.Windows.RoutedEventArgse)
{
lblHello.Content="HelloWorldChanged";
}
]]>
</x:Code>
</StackPanel>
</Window>

publicpartialclassWindow3:Window
{
publicWindow3()
{
this.Activated+=newEventHandler(Window1_Activated);
this.Closing+=newSystem.ComponentModel.CancelEventHandler(Window1_Closing);
this.ContentRendered+=newEventHandler(Window1_ContentRendered);
this.Deactivated+=newEventHandler(Window1_Deactivated);
this.Loaded+=newRoutedEventHandler(Window1_Loaded);
this.Closed+=newEventHandler(Window1_Closed);
this.Unloaded+=newRoutedEventHandler(Window1_Unloaded);
this.SourceInitialized+=newEventHandler(Window1_SourceInitialized);

InitializeComponent();
}

voidWindow1_Unloaded(objectsender,RoutedEventArgse)
{
Debug.WriteLine("Unloaded");
}

voidWindow1_SourceInitialized(objectsender,EventArgse)
{
Debug.WriteLine("SourceInitialized");
}

voidWindow1_Loaded(objectsender,RoutedEventArgse)
{
Debug.WriteLine("Loaded");
}

voidWindow1_Deactivated(objectsender,EventArgse)
{
Debug.WriteLine("Deactivated");
}

voidWindow1_ContentRendered(objectsender,EventArgse)
{
Debug.WriteLine("ContentRendered");
}

voidWindow1_Closing(objectsender,System.ComponentModel.CancelEventArgse)
{
Debug.WriteLine("Closing");
MessageBoxResultdr=MessageBox.Show("Cancelthewindow?",
"Answer",MessageBoxButton.YesNo,MessageBoxImage.Question);
if(dr==MessageBoxResult.No)
{
e.Cancel=true;
}
}

voidWindow1_Closed(objectsender,EventArgse)
{
Debug.WriteLine("Closed");
}

voidWindow1_Activated(objectsender,EventArgse)
{
Debug.WriteLine("Activated");
}

}

执行结果为：

<Windowx:Class="WPFApplications.Window2"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window2"Height="300"Width="300">
<StackPanel>
<Labelx:Name="lblHello">Hello,World!</Label>
</StackPanel>
</Window>

后台代码：

publicpartialclassWindow2:Window
{
publicWindow2()
{
InitializeComponent();
Threadthread=newThread(ModifyUI);
thread.Start();
}

privatevoidModifyUI()
{
//模拟一些工作正在进行
Thread.Sleep(TimeSpan.FromSeconds(5));
lblHello.Content="Hello,Dispatcher";
}
}

错误截图：

privatevoidModifyUINew()
{
//模拟一些工作正在进行
Thread.Sleep(TimeSpan.FromSeconds(5));
this.Dispatcher.BeginInvoke(DispatcherPriority.Normal,(ThreadStart)delegate()
{
lblHello.Content="Hello,Dispatcher";
});
}

privatevoidbtnHello_Click(objectsender,RoutedEventArgse)
{
newThread(()=>
{
Application.Current.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
newAction(()=>
{
Thread.Sleep(TimeSpan.FromSeconds(5));
this.lblHello.Content=DateTime.Now.ToString();
}));
}).Start();
}

<Windowx:Class="WPFApplications.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1"Height="300"Width="300">
<StackPanel>
<Label>Hello,World!</Label>
</StackPanel>
</Window>

publicpartialclassWindow1:Window
{
publicWindow1()
{
InitializeComponent();
PrintLogicalTree(0,this);
}

protectedoverridevoidOnContentRendered(EventArgse)
{
base.OnContentRendered(e);
PrintVisualTree(0,this);
}

voidPrintLogicalTree(intdepth,objectobj)
{
//打印空格，方便查看
Debug.WriteLine(newstring('',depth)+obj);

//如果不是DependencyObject，如string等类型
if(!(objisDependencyObject))return;

//递归打印逻辑树
foreach(objectchildinLogicalTreeHelper.GetChildren(
objasDependencyObject))
{
PrintLogicalTree(depth+1,child);
}
}

voidPrintVisualTree(intdepth,DependencyObjectobj)
{
//打印空格，方便查看
Debug.WriteLine(newstring('',depth)+obj);

//递归打印视觉树
for(inti=0;i<VisualTreeHelper.GetChildrenCount(obj);i++)
{
PrintVisualTree(depth+1,VisualTreeHelper.GetChild(obj,i));
}
}
}