解决反射加载Xap包中的图片路径问题

时间：2010-08-27 来源：吹风

图片路径问题

　　最近做的silverlight项目框架设计是将每个模块都做成单独的silverlight项目，这些单独项目生成的Xap包通过在父silverlight程序中

反射实现加载。在实际开发过程中，用blend添加的图片默认路径是"\123.jpg”。编译后图片会做为内容一起打包到Xap中。在图片路径中

以"\"开始的路径，silverlight运行时会从父silverlight Xap包中搜索文件，然后显示。而反射加载的xap包中的图片会找不到路径。

解决方法

　　解决此问题比较简单，我们需要将反射xap包中的图片设置为资源，然后将图片路径"\123.jpg”修改为"123.jpg”。

　　在图片路径中如果没有"\"，silverlight运行时将会从资源中搜索图片。

xap包反射加载类

代码

    public class XapLoader
    {
        public static UserControl LoadStream(Stream e, string MainPage, string MainDll)
        {
            string appMainfest = new StreamReader(Application.GetResourceStream(
                                                    new StreamResourceInfo(e, null)
                                                    , new Uri("AppManifest.xaml", UriKind.Relative)).Stream
                                                    ).ReadToEnd();

            XElement xe = (XDocument.Parse(appMainfest)).Root;

            var results = from deploymentPart in xe.Elements().Elements()
                          where deploymentPart.Attributes("Source").Count() > 0
                          select deploymentPart.Attribute("Source").Value;

            Assembly asse = null;

            foreach (var deploymentpart in results)
            {
                string source = deploymentpart;

                StreamResourceInfo streamInfo = Application.GetResourceStream(new StreamResourceInfo(e, "application/binary"),
                                                                              new Uri(source, UriKind.Relative));

                AssemblyPart assP = new AssemblyPart();

                if (source == MainDll)
                {
                    asse = assP.Load(streamInfo.Stream);
                }
                else
                {
                    assP.Load(streamInfo.Stream);
                }
            }

            return asse.CreateInstance(MainPage) as UserControl;
        }

        public void loadUri(Uri xapuri, string MainPage, string MainDll)
        {
            WebClient wc = new WebClient();
            wc.OpenReadCompleted += new OpenReadCompletedEventHandler((s, e) => {
                string appMainfest = new StreamReader(Application.GetResourceStream(
                                                    new StreamResourceInfo(e.Result, null)
                                                    , new Uri("AppManifest.xaml", UriKind.Relative)).Stream
                                                    ).ReadToEnd();

                XElement xe = (XDocument.Parse(appMainfest)).Root;

                var results = from deploymentPart in xe.Elements().Elements()
                              where deploymentPart.Attributes("Source").Count() > 0
                              select deploymentPart.Attribute("Source").Value;

                Assembly asse = null;

                foreach (var deploymentpart in results)
                {
                    string source = deploymentpart;

                    StreamResourceInfo streamInfo = Application.GetResourceStream(new StreamResourceInfo(e.Result, "application/binary"),
                                                                                  new Uri(source, UriKind.Relative));

                    AssemblyPart assP = new AssemblyPart();

                    if (source == MainDll)
                    {
                        asse = assP.Load(streamInfo.Stream);
                    }
                    else
                    {
                        assP.Load(streamInfo.Stream);
                    }
                }

                UIElement uie = asse.CreateInstance(MainPage) as UIElement;


                if (OnLoadComplete != null)
                    OnLoadComplete(this, new XapEventArgs() { XapRootUIElement = uie });
            });
            wc.OpenReadAsync(xapuri);
        }

        public event EventHandler<XapEventArgs> OnLoadComplete;
    }

    public class XapEventArgs : EventArgs
    {
        public UIElement XapRootUIElement { get; set; }
    }