2.0Tip/Trick之加载XAP, 加载XAML, 加载DLL, AppManifest.xaml文件说明, 自定义鼠标指针

介绍
Silverlight 2.0 提示和技巧系列

• 加载XAP - 加载指定的 xap 文件到当前的 Silverlight 应用程序中 
• 加载XAML - 加载指定的 xaml 文件到当前的 Silverlight 应用程序中
• 加载DLL - 加载指定的 dll 文件，并调用其中的方法或加载其中的控件
• AppManifest.xaml文件说明 - 简要说明 AppManifest.xaml 文件内容中各个节点的作用 
• 自定义鼠标指针 - 实现自定义的鼠标指针，即鼠标跟随

在线DEMO
http://www.cnblogs.com/webabcd/archive/2008/10/09/1307486.html


示例
1、在 Silverlight 程序中加载指定的 xap 文件
LoadXap.xaml

<UserControl x:Class="Silverlight20.Tip.LoadXap"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Grid x:Name="LayoutRoot" Background="White">
        <StackPanel>
            <Button x:Name="load" Content="加载游戏 - 俄罗斯方块" Click="load_Click" Margin="5" />
            <Grid x:Name="container" Margin="5" />
        </StackPanel>
    </Grid>
</UserControl>

LoadXap.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;

using System.Windows.Resources;
using System.IO;
using System.Xml.Linq;
using System.Reflection;

namespace Silverlight20.Tip
{
    public partial class LoadXap : UserControl
    {
        public LoadXap()
        {
            InitializeComponent();
        }

        private void load_Click(object sender, RoutedEventArgs e)
        {
            Uri uri = new Uri("YYTetris.xap", UriKind.Relative);

            // 用 WebClient 下载指定的 XAP
            WebClient client = new WebClient();
            client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
            client.OpenReadAsync(uri);
        }

        void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
        {
            /**//*
             * StreamResourceInfo - 提供对通过 Silverlight 应用程序模型检索资源的支持
             * AssemblyPart - 包含在 Silverlight 程序内的程序集
             *     AssemblyPart.Load() - 加载指定的程序集到当前应用程序域中
             * Application.GetResourceStream() - 对 zip 类型的文件自动解压缩
             */

            // YYTetris.xap 的 AppManifest.xaml 的信息如下
            /**//* 
            <Deployment xmlns="http://schemas.microsoft.com/client/2007/deployment" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" EntryPointAssembly="YYTetris" EntryPointType="YYTetris.App" RuntimeVersion="2.0.31005.0">
              <Deployment.Parts>
                <AssemblyPart x:Name="YYTetris" Source="YYTetris.dll" />
              </Deployment.Parts>
            </Deployment>    
            */

            // 可以通过 Deployment.Current 检索 AppManifest.xaml 中的 Deployment 对象

            // 取得 XAP 的 AppManifest.xaml 中的 Deployment.Parts 内的全部 AssemblyPart 节点信息
            StreamResourceInfo resource = App.GetResourceStream(
                new StreamResourceInfo(e.Result, null), 
                new Uri("AppManifest.xaml", UriKind.Relative));
            string resourceManifest = new StreamReader(resource.Stream).ReadToEnd();
            List<XElement> assemblyParts = XDocument.Parse(resourceManifest).Root.Elements().Elements().ToList();

            Assembly assembly = null;

            foreach (XElement element in assemblyParts)
            {
                // 取出 AssemblyPart 的 Source 指定的 dll
                string source = element.Attribute("Source").Value;
                AssemblyPart assemblyPart = new AssemblyPart();
                StreamResourceInfo streamInfo = App.GetResourceStream(
                    new StreamResourceInfo(e.Result, "application/binary"),
                    new Uri(source, UriKind.Relative));

                if (source == "YYTetris.dll")
                    assembly = assemblyPart.Load(streamInfo.Stream);
                else
                    assemblyPart.Load(streamInfo.Stream);
            }

            // 实例化 YYTetris.xap 的主函数
            var type = assembly.GetType("YYTetris.Page");
            var yyTetris = Activator.CreateInstance(type) as UIElement;

            // 添加 YYTetris.xap 到指定的容器内，并更新 UI
            container.Children.Add(yyTetris);
            container.UpdateLayout();
        }
    }
}

2、在 Silverlight 程序中加载指定的 xaml 文件
LoadXaml.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;

using System.Windows.Resources;
using System.IO;

namespace Silverlight20.Tip
{
    public partial class LoadXaml : UserControl
    {
        public LoadXaml()
        {
            InitializeComponent();

            this.Loaded += new RoutedEventHandler(LoadXaml_Loaded);
        }

        void LoadXaml_Loaded(object sender, RoutedEventArgs e)
        {
            // 获取指定的 Xaml
            Uri uri = new Uri("/Silverlight20;component/Tip/XamlDemo.xaml", UriKind.Relative);
            StreamResourceInfo resource = App.GetResourceStream(uri);

            using (StreamReader reader = new StreamReader(resource.Stream))
            {
                // XamlReader.Load() - 加载 Xaml
                UserControl control =
                    System.Windows.Markup.XamlReader.Load(reader.ReadToEnd()) as UserControl;

                LayoutRoot.Children.Add(control);
            }
        }
    }
}

3、在 Silverlight 程序中加载指定的 dll 文件，并调用其中的方法或加载其中的控件
LoadDllDemo.Test.cs

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace LoadDllDemo
{
    public class Test
    {
        /**//// <summary>
        /// Say Hello 的方法
        /// </summary>
        /// <param name="name">名字</param>
        /// <returns></returns>
        public string Hello(string name)
        {
            return "Hello: " + name;
        }
    }
}

LoadDll.xaml

<UserControl x:Class="Silverlight20.Tip.LoadDll"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Grid x:Name="LayoutRoot" Background="White">
        
        <TextBlock x:Name="lblResult" Margin="5" />
        
    </Grid>
</UserControl>

LoadDll.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;

using System.Reflection;

namespace Silverlight20.Tip
{
    public partial class LoadDll : UserControl
    {
        public LoadDll()
        {
            InitializeComponent();

            this.Loaded += new RoutedEventHandler(LoadDll_Loaded);
        }

        void LoadDll_Loaded(object sender, RoutedEventArgs e)
        {
            Uri uri = new Uri("LoadDllDemo.dll", UriKind.Relative);

            // 用 WebClient 下载指定的 DLL
            WebClient client = new WebClient();
            client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
            client.OpenReadAsync(uri);
        }

        void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
        {
            // 加载指定的 dll
            AssemblyPart assemblyPart = new AssemblyPart();
            Assembly assembly = assemblyPart.Load(e.Result);

            // 调用 LoadDllDemo.Test 的 Hello 方法，参数为 webabcd
            Type type = assembly.GetType("LoadDllDemo.Test");
            object obj = Activator.CreateInstance(type);
            MethodInfo methodInfo = type.GetMethod("Hello");
            lblResult.Text = methodInfo.Invoke(obj, new object[] { "webabcd" }).ToString();


            // 注：
            // AssemblyPart.Load() 用于把程序集加载到当前程序域
            // 此特性可实现按需加载程序集（部署时，把这类的程序集从 xap 包中移除，用到时再调用指定发方法下载即可）
        }
    }
}

4、简要说明 AppManifest.xaml 文件内容中各个节点的作用

<Deployment xmlns="http://schemas.microsoft.com/client/2007/deployment" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" EntryPointAssembly="Silverlight20" EntryPointType="Silverlight20.App" RuntimeVersion="2.0.31005.0">
  <Deployment.Parts>
    <AssemblyPart x:Name="Silverlight20" Source="Silverlight20.dll" />
    <AssemblyPart x:Name="Microsoft.Windows.Controls" Source="Microsoft.Windows.Controls.dll" />
  </Deployment.Parts>
</Deployment>

一个 Silverlight 应用程序包（xap）内都会包含 AppManifest.xaml 文件，其内标识着打包的程序集和程序入口等信息

Deployment - 根节点
EntryPointAssembly - 程序入口的程序集
EntryPointType - 程序入口的类型
RuntimeVersion - 所需的 Silverlight 插件的版本
AssemblyPart - 标识 Silverlight 程序包（xap）内的程序集。其中的 Source 属性用于标识程序集的路径

5、自定义鼠标指针，即鼠标跟随
CustomMouseCursor.xaml

<UserControl x:Class="Silverlight20.Tip.CustomMouseCursor"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Grid x:Name="LayoutRoot" Background="Bisque">
        <Canvas x:Name="canvas">
            <Ellipse x:Name="ellipse" Width="30" Height="30" Fill="Red" />
        </Canvas>
    </Grid>
</UserControl>

CustomMouseCursor.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.Tip
{
    public partial class CustomMouseCursor : UserControl
    {
        public CustomMouseCursor()
        {
            InitializeComponent();

            this.MouseMove += new MouseEventHandler(MouseFollow_MouseMove);
        }

        // 自定义鼠标指针的实现如下。鼠标跟随也是同理的做
        void MouseFollow_MouseMove(object sender, MouseEventArgs e)
        {
            ellipse.SetValue(Canvas.LeftProperty, e.GetPosition(canvas).X - ellipse.ActualWidth / 2);
            ellipse.SetValue(Canvas.TopProperty, e.GetPosition(canvas).Y - ellipse.ActualHeight / 2);
        }
    }
}