X名称空间里面的成员(如X:Name,X:Class)都是写给XAML编译器看的、用来引导XAML代码将XAML代码编译为CLR代码。
4.1X名称空间里面到底都有些什么?
x名称空间映射的是:http://schemas.microsoft.com/winfx/2006/xaml,望文生义,它包含的类均与解析XAML语言相关,所以亦称之为“XAML名称空间”。
与C#语言一样,XAML也有自己的编译器。XAML语言被解析并编译,最终形成微软中间语言保存在程序集中。在解析和编译XAML的过程中,我们经常要告诉编译器一些重要的信息,如XAML编译的结果应该和哪个C#代码编译的结果合并、使用XAML声明的元素是public还是private访问级别等等。这些让程序员能够与XAML编译器沟通的工具就存在X:名称空间中。
我们注意到,它分为Attribute、标签扩展、XAML指令元素三个种类。下面我们讲讲它们的具体用法:
4.2 X名称空间中的Attribute
前面我们已经讲过,Attribute和Property是两个层面上的东西,Attribute是语言层面上的东西,是给编译器看的,Property是面向对象层面上的东西,是给编程逻辑看。而且一个标签中的Attribute大部分对应对象的Property。在使用XAML编程的时候,如果你想给它加一点特殊的标记来改变XAML对它的解析,这时候就需要额外的给它添加一些Attribute了。比如,你想告诉XAML编译器将哪个编译结果和那个C#编译的类合并,这时候就必须为这个标签添加X:Class Attribute来告诉编译器。X:Class并不是对象成员,而是重X空间硬贴上去的。让我们浏览一下常用的Attribute。
4.2.1 x:Class
这个Attribute是告诉XAML编译器将XAML编译器编译的结果和后台编译结果的哪一个类进行合并,使用x:Class有以下几点要求:
- 这个Attribute只能用于根节点。
- 使用x:Class的根节点的类型要与x:Class的值所指示的一致。
- x:Class的值所指示的类型在声明的时候必须使用partial关键字。
- x:Class已经在剖析最简单的XAML的时候已经讲过,在这就不多讲了。
4.2.2 X:ClassModiffier
这段代码是告诉XAML编译器有标签编译成的类具有什么样的访问级别。
使用这个Attribute的时候需要注意的是:
- 标签必须具有x:Class Attribute。
- X:ClassModiffier的值必须与X:Class所指定类的访问权限一致。
- X:ClassModiffier的值随后台代码编译语言的不同而有所不同。
- <Window x:Class="WpfApplication2.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">
- <Grid>
- <StackPanel Height="218" HorizontalAlignment="Left" Margin="19,31,0,0" VerticalAlignment="Top" Width="237">
- <TextBox Height="23" Width="120" />
- <Button Content="Button" Height="23" Width="75" />
- </StackPanel>
- </Grid>
- </Window>
- private void Button_Click(object sender, RoutedEventArgs e)
- {
- StackPanel panel = this.Content as StackPanel;
- TextBox textBox = panel.Children[0] as TextBox;
- if (!string.IsNullOrEmpty(textBox.Name))
- {
- textBox.Text = textBox.Text;
- }
- else
- {
- textBox.Text = "NULL";
- }
- }
- <StackPanel Height="218" HorizontalAlignment="Left" Margin="19,31,0,0" VerticalAlignment="Top" Width="237">
- <TextBox Height="23" Width="120" x:Name="txtName" x:FieldModifier="internal"/>
- <Button Content="Button" Height="23" Width="75" Click="Button_Click" x:Name="btntest" x:FieldModifier="public"/>
- </StackPanel>
- <Window x:Class="WpfApplication2.Window4"
- xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
- xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
- xmlns:sys="clr-namespace:System;assembly=mscorlib"
- xmlns:local="clr-namespace:WpfApplication2"
- Title="Window4" Height="369" Width="675">
- <Window.Resources>
- <local:Human x:Key="human" Child="ABC"></local:Human>
- <sys:String x:Key="myString">测试</sys:String>
- <Style x:Key="{x:Type Button}" TargetType="{x:Type Button}">
- <Setter Property="Width" Value="30"></Setter>
- <Setter Property="Background" Value="black"></Setter>
- </Style>
- </Window.Resources>
- <Grid>
- <Label Content="{ StaticResource ResourceKey=myString}" Height="28" HorizontalAlignment="Left" Margin="177,81,0,0" Name="label1" VerticalAlignment="Top" />
- </Grid>
- </Window>
- string str = this.FindResource("myString") as string;
- this.label1.Content = str;
- <UserControl x:Class="WpfApplication2.UserControl1"
- xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
- xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
- xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
- xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
- mc:Ignorable="d"
- d:DesignHeight="52" d:DesignWidth="128">
- <Grid>
- <Button Content="Button" Height="30" HorizontalAlignment="Left" Margin="10,10,0,0" Name="button1" VerticalAlignment="Top" Width="106" Click="button1_Click" />
- </Grid>
- </UserControl>
- /// <summary>
- /// UserControl1.xaml 的交互逻辑
- /// </summary>
- public partial class UserControl1 : UserControl
- {
- public UserControl1()
- {
- InitializeComponent();
- }
- public Type MyWindowType { get; set; }
- private void button1_Click(object sender, RoutedEventArgs e)
- {
- Window myWin = Activator.CreateInstance(this.MyWindowType) as Window;
- if(myWin!=)
- {
- myWin.Show();
- }
- }
- }
- <Window x:Class="WpfApplication2.Window4"
- xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
- xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
- xmlns:sys="clr-namespace:System;assembly=mscorlib"
- xmlns:local="clr-namespace:WpfApplication2"
- Title="Window4" Height="369" Width="675">
- <Window.Resources>
- <local:Human x:Key="human" Child="ABC"></local:Human>
- <sys:String x:Key="myString">测试</sys:String>
- <Style x:Key="{x:Type Button}" TargetType="{x:Type Button}">
- <Setter Property="Width" Value="30"></Setter>
- <Setter Property="Background" Value="black"></Setter>
- </Style>
- </Window.Resources>
- <Grid>
- <local:UserControl1 HorizontalAlignment="Left" Margin="292,244,0,0" x:Name="userControl11" VerticalAlignment="Top" MyWindowType="{x:Type TypeName=local:Window1}"/>
- </Grid>
- </Window>
- UserWindowType="{x:Type local:Window1}"
- <Window x:Class="WpfApplication2.Window4"
- xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
- xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
- xmlns:sys="clr-namespace:System;assembly=mscorlib"
- xmlns:local="clr-namespace:WpfApplication2"
- Title="Window4" Height="369" Width="675">
- <Window.Resources>
- <Style x:Key="{x:Type Button}" TargetType="{x:Type Button}">
- <Setter Property="Width" Value="30"></Setter>
- <Setter Property="Background" Value="black"></Setter>
- </Style>
- </Window.Resources>
- <Grid>
- <Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="180,256,0,0" Name="button1" VerticalAlignment="Top" Click="button1_Click" />
- <Label Content="{ StaticResource ResourceKey=myString}" Height="28" HorizontalAlignment="Left" Margin="177,81,0,0" Name="label1" VerticalAlignment="Top" />
- <Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="10,10,0,0" Name="button2" VerticalAlignment="Top" />
- <Button Content="{x:Static local:Window4.Test}" Height="23" HorizontalAlignment="Left" Margin="128,12,0,0" Name="button3" VerticalAlignment="Top" Style="{x:Null}"/>
- </Grid>
- </Window>
- <Window x:Class="WpfApplication2.Window4"
- xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
- xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
- xmlns:sys="clr-namespace:System;assembly=mscorlib"
- xmlns:local="clr-namespace:WpfApplication2"
- Title="Window4" Height="369" Width="675">
- <Grid>
- <ListBox Height="100" HorizontalAlignment="Left" Margin="435,110,0,0" Name="listBox1" VerticalAlignment="Top" Width="176">
- <ListBox.ItemsSource>
- <x:Array Type="sys:String">
- <sys:String>Jim</sys:String>
- <sys:String>Darren</sys:String>
- <sys:String>Frank</sys:String>
- </x:Array>
- </ListBox.ItemsSource>
- </ListBox>
- </Grid>
- </Window>
- public Window4()
- {
- InitializeComponent();
- //SolidColorBrush brush = new SolidColorBrush();
- //brush.Color = Colors.Blue;
- //this.rectangle1.Fill = brush;
- }
- public static string Test = "明月松间照,清泉石上流。";
- <Window x:Class="WpfApplication2.Window4"
- xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
- xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
- xmlns:sys="clr-namespace:System;assembly=mscorlib"
- xmlns:local="clr-namespace:WpfApplication2"
- Title="Window4" Height="369" Width="675">
- <Grid>
- <Button Content="{x:Static local:Window4.Test}" Height="23" HorizontalAlignment="Left" Margin="128,12,0,0" Name="button3" VerticalAlignment="Top" Style="{x:Null}"/>
- </Grid>
- </Window>
XAML指令元素只有两个:
- x:Code
- x:XData