XAML标签元素在silverlight运行时被转换成相应的对象，通过XamlReader类的Load方法，动态创建UI元素：
- 指定一条XAML内容字符串,为按照XML规则运行,XamlReader.Load()现在需要你在你的XAML文件中指定一个xmlns；
- 通过XamlReader.Load方法把元素在内存中编译（这样就可以得到UI元素对象的引用，也有可能是null，或者报错)；
- 最后把它添加到容器的子控件中。
下面我们来制作一个简单的时钟，Page.xaml如下：
<UserControl x:Class="OpenXmlVideo2.Page"
xmlns=" [url]http://schemas.microsoft.com/client/2007[/url]"
xmlns:x=" [url]http://schemas.microsoft.com/winfx/2006/xaml[/url]"
Width="187" Height="97">
<Canvas x:Name="EClock" Height="97" Width="187" >
</Canvas>
</UserControl>
using
System;
using
System.Collections.Generic;
using
System.Linq;
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;
using
System.Windows.Markup;
namespace
OpenXmlVideo2
{
public partial class Page : UserControl
{
private TextBlock textBlock1;
private System.Windows.Threading.DispatcherTimer timer;
public Page()
{
InitializeComponent();
this.Loaded += new RoutedEventHandler(Page_Loaded);
}
void Page_Loaded(object sender, RoutedEventArgs e)
{
string xaml = string.Empty;
xaml = "<TextBlock xmlns=\"http://schemas.microsoft.com/client/2007\" Margin=\"14,11,19,12\" Name=\"textBlock1\" FontFamily=\"Time New Roman\" FontSize=\"40\">00:00:00</TextBlock>";
textBlock1 = XamlReader.Load(xaml) as TextBlock;
//Loaded就是TextBlock的加载事件，那么里面的textBlock1_Loaded自然就是事件处理程序的名称。
textBlock1.Loaded += new RoutedEventHandler(textBlock1_Loaded);
//改变附加属性（attached properties）,必须使用SetValue方法
textBlock1.SetValue(Canvas.LeftProperty, 2);
textBlock1.SetValue(Canvas.TopProperty, 2);
//加把textBlock1对象做为子对象添加到画布（和asp.net页的控件树的道理相拟）
this.EClock.Children.Add(textBlock1);
}
void textBlock1_Loaded(object sender, RoutedEventArgs e)
{
//使用了DispatcherTimer，我把间隔设置为1秒。该计时器的间隔事件也是Tick事件
timer = new System.Windows.Threading.DispatcherTimer();
timer.Interval = new TimeSpan(0, 0, 1); //间隔1秒
timer.Tick += new EventHandler(timer_Tick);
timer.Start();
}
void timer_Tick(object sender, EventArgs e)
{
textBlock1.Text = DateTime.Now.ToLongTimeString();
}
}
}
xmlns=" [url]http://schemas.microsoft.com/client/2007[/url]"
xmlns:x=" [url]http://schemas.microsoft.com/winfx/2006/xaml[/url]"
Width="187" Height="97">
<Canvas x:Name="EClock" Height="97" Width="187" >
</Canvas>
</UserControl>
Page.xaml.cs如下：
using
System;
using
System.Collections.Generic;
using
System.Linq;
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;
using
System.Windows.Markup;
namespace
OpenXmlVideo2
{ public partial class Page : UserControl { private TextBlock textBlock1; private System.Windows.Threading.DispatcherTimer timer; public Page() { InitializeComponent(); this.Loaded += new RoutedEventHandler(Page_Loaded); } void Page_Loaded(object sender, RoutedEventArgs e) { string xaml = string.Empty; xaml = "<TextBlock xmlns=\"http://schemas.microsoft.com/client/2007\" Margin=\"14,11,19,12\" Name=\"textBlock1\" FontFamily=\"Time New Roman\" FontSize=\"40\">00:00:00</TextBlock>"; textBlock1 = XamlReader.Load(xaml) as TextBlock; //Loaded就是TextBlock的加载事件，那么里面的textBlock1_Loaded自然就是事件处理程序的名称。 textBlock1.Loaded += new RoutedEventHandler(textBlock1_Loaded); //改变附加属性（attached properties）,必须使用SetValue方法 textBlock1.SetValue(Canvas.LeftProperty, 2); textBlock1.SetValue(Canvas.TopProperty, 2); //加把textBlock1对象做为子对象添加到画布（和asp.net页的控件树的道理相拟） this.EClock.Children.Add(textBlock1); } void textBlock1_Loaded(object sender, RoutedEventArgs e) { //使用了DispatcherTimer，我把间隔设置为1秒。该计时器的间隔事件也是Tick事件 timer = new System.Windows.Threading.DispatcherTimer(); timer.Interval = new TimeSpan(0, 0, 1); //间隔1秒 timer.Tick += new EventHandler(timer_Tick); timer.Start(); } void timer_Tick(object sender, EventArgs e) { textBlock1.Text = DateTime.Now.ToLongTimeString(); } }}
本文转自 张善友 51CTO博客，原文链接：http://blog.51cto.com/shanyou/73546，如需转载请自行联系原作者
