Silverlight上传图片示例
本文将演示如何使用Silverlight上传图片。
在Visual Studio 2008中新建一个Silverlight项目，创建时选中“Host the Silverlight application in a new Web site”复选框。
在MainPage中添加一个Button和一个TextBlock，分别用来浏览图片和显示上传后图片的名称。在Button的Click事件中添加如下代码：
private void btnUpload_Click(object sender, RoutedEventArgs e) 
{ 
OpenFileDialog dlg = new OpenFileDialog(); dlg.Multiselect = false; dlg.Filter = "JPG 图片 (*.jpg)|*.jpg|PNG 图片 (*.png)|*.png"; bool? result = dlg.ShowDialog(); if (result != null && result == true) 
{ 
string name = dlg.File.Name; string extension = name.Substring(name.LastIndexOf('.'), name.Length - name.LastIndexOf('.')); //取得扩展名（包括“.”） string uploadedName = DateTime.Now.ToString("yyyyMMddhhmmss") + extension; // 根据当前时间重命名 uploadImage(uploadedName, dlg.File.OpenRead()); uploadedImageName.Text = string.Format("上传成功！已重命名为：{0}", uploadedName); 
} 
}uploadImage方法和其中用到的uploadData方法的代码如下：
private void uploadImage(string fileName, Stream data) { Uri uri = new Uri(string.Format("/DataHandler.ashx?filename={0}", fileName), UriKind.Relative); WebClient client = new WebClient(); client.OpenWriteCompleted += delegate(object s, OpenWriteCompletedEventArgs e) { uploadData(data, e.Result); e.Result.Close(); data.Close(); }; client.OpenWriteAsync(uri); }private void uploadData(Stream input, Stream output) { byte[] buffer = new byte[4096]; int bytes; while ((bytes = input.Read(buffer, 0, buffer.Length)) != 0) { output.Write(buffer, 0, bytes); } }在网站中添加一个Generic Handler 命名为DataHandler.ashx，后置代码如下：
public void ProcessRequest(HttpContext context) { string filename = context.Request.QueryString["filename"].ToString(); public void ProcessRequest(HttpContext context) { string filename = context.Request.QueryString["filename"].ToString(); using (FileStream fs = File.Create(context.Server.MapPath("~/ClientBin/Images/" + filename))) { SaveImage(context.Request.InputStream, fs); } } private void SaveImage(Stream stream, FileStream fs) { byte[] buffer = new byte[4096]; int bytesRead; while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) != 0) { fs.Write(buffer, 0, bytesRead); } } public bool IsReusable { get { return false; } } 在ClientBin文件夹下面新建一个文件夹Images，到此全部工作完成，运行程序就可以上传图片了