Silverlight 实现文件上传

通过web进行文件上传，一般要使用form表单，在silverlight里面没有内置form表单功能，参考牛人文章，实现Silverlight文件上传。只要Web.config文件中httpRuntime节点的maxRequestLength属性足够大，上传就不受限制。

项目结构图：

MainPage类源码:

namespace SilverlightDownAndUploadFile
{
    public partial class MainPage : UserControl
    {
        private OpenFileDialog ofd;
        private AutoResetEvent autoEvent = new AutoResetEvent(false);

        public MainPage()
        {
            InitializeComponent();
        }

        private static HttpWebRequest CreateWebRequest(string requestUriString, string httpMethod)
        {
            try
            {
                string ticks = Guid.NewGuid().ToString();
                requestUriString = requestUriString + "/" + ticks;
                HttpWebRequest request = (HttpWebRequest)WebRequestCreator.ClientHttp.Create(new Uri(requestUriString));
                request.Method = httpMethod;

                return request;
            }
            catch (Exception ex)
            {
                return null;
            }
        }
        #region 上传

        private void ReadFileToRequestStream(BinaryReader fileStream, HttpWebRequest request)
        {
            try
            {
                request.BeginGetRequestStream((requestAsyncResult) =>
                {
                    Stream requestStream = null;
                    try
                    {
                        requestStream = request.EndGetRequestStream(requestAsyncResult);
                        if (null != requestStream)
                        {
                            SilverlightMultipartFormData form = new SilverlightMultipartFormData();
                            //form.AddFormField("devilField", "中国人");
                            int maxBufferLen = 25 * 1024;
                            byte[] buffer = new byte[maxBufferLen];
                            int bytesRead = fileStream.Read(buffer, 0, maxBufferLen);
                            int i = 0;
                            while (bytesRead != 0)
                            {
                                i++;
                                byte[] newBuffer = GetNewBuffer(buffer, bytesRead);
                                form.AddStreamFile("package" + i, "package" + i, newBuffer);
                                buffer = new byte[maxBufferLen];
                                bytesRead = fileStream.Read(buffer, 0, maxBufferLen);
                            }

                            form.PrepareFormData();//结束
                            fileStream.Close();
                            request.ContentType = "multipart/form-data; boundary=" + form.Boundary;
                            foreach (byte byt in form.GetFormData())
                            {
                                requestStream.WriteByte(byt);
                            }
                            requestStream.Close();
                            autoEvent.Set();//开始上传
                        }
                    }
                    catch (Exception ex)
                    { }
                    finally
                    {
                        if (null != requestStream)
                            requestStream.Close();
                        if (null != fileStream)
                            fileStream.Close();
                    }
                }, null);
            }
            catch (Exception ex)
            {

            }
        }

        private void RequestAndUploadFile(BinaryReader br)
        {
            try
            {
                if (null == br) return;
                HttpWebRequest request = CreateWebRequest("http://localhost:13953/Upload.ashx", "POST");
                ReadFileToRequestStream(br, request);
                autoEvent.WaitOne();//等待流写入完毕

                //上传
                request.BeginGetResponse(
                            (asyncResult) =>
                            {
                                if (request.HaveResponse)
                                {
                                    try
                                    {
                                        WebResponse response = request.EndGetResponse(asyncResult);

                                        Stream responseStream = response.GetResponseStream();
                                        int bufferLen = 1024;
                                        byte[] buffer = new byte[bufferLen];
                                        int bytesRead = responseStream.Read(buffer, 0, bufferLen);
                                        responseStream.Close();

                                        string responseText = System.Text.Encoding.UTF8.GetString(buffer, 0, bytesRead);

                                        ShowUploadResult(true);
                                    }
                                    catch (Exception ex)
                                    {
                                        ShowUploadResult(false);
                                    }
                                }
                            }, null);
            }
            catch (Exception ex)
            {
                ShowUploadResult(false);
            }
        }

        private void btnUpload_Click(object sender, RoutedEventArgs e)
        {
            ofd = new OpenFileDialog();
            ofd.Filter = "(*.rar)|*.rar";
            ofd.Multiselect = false;

            if (ofd.ShowDialog() == true)
            {
                uploadProgress.Visibility = Visibility.Visible;
                BinaryReader br = new BinaryReader(ofd.File.OpenRead());
                RequestAndUploadFile(br);
            }
        }

        private void ShowUploadResult(bool isSucess)
        {
            this.Dispatcher.BeginInvoke(
                () =>
                {
                    uploadProgress.Visibility = Visibility.Collapsed;
                    if (isSucess)
                        MessageBox.Show("上传成功");
                    else
                        MessageBox.Show("上传失败.");
                });
        }
        #endregion

        /// <summary>
        /// 获了实际接读取到的字节数组
        /// </summary>
        /// <param name="buffer"></param>
        /// <param name="bytesRead"></param>
        /// <returns></returns>
        private byte[] GetNewBuffer(byte[] buffer, int bytesRead)
        {
            byte[] newBuffer = new byte[bytesRead];
            for (int i = 0; i < bytesRead; i++)
            {
                newBuffer[i] = buffer[i];
            }
            return newBuffer;
        }
    }
}

Upload.ashx文件源码:

namespace SilverlightDownAndUploadFile.Web
{
    /// <summary>
    /// Upload 的摘要说明
    /// </summary>
    public class Upload : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            //context.Response.ContentType = "text/plain";
            //context.Response.Write("Hello World");
            Stream stream = null;
            try
            {
                string path = context.Server.MapPath("~/Files/upload.rar");
                int i = 0;
                while (true)
                {
                    i++;
                    string packageName = "package" + i;
                    HttpPostedFile uploadFile = context.Request.Files[packageName];
                    if (null != uploadFile)
                    {
                        stream = context.Request.Files[packageName].InputStream;
                        FileStream fs = null;
                        if (i == 1 && File.Exists(path))
                        {
                            fs = new FileStream(path, FileMode.Create, FileAccess.Write);
                        }
                        else
                        {
                            fs = new FileStream(path, FileMode.Append, FileAccess.Write);
                        }

                        using (BinaryWriter bw = new BinaryWriter(fs))
                        {
                            int maxBufferLen = 20 * 1024;//20K
                            byte[] buffer = new byte[maxBufferLen];
                            int bytesRead = stream.Read(buffer, 0, maxBufferLen);
                            while (bytesRead != 0)
                            {
                                byte[] newBuff = GetNewBuffer(buffer, bytesRead);
                                bw.Write(newBuff, 0, newBuff.Length);

                                buffer = new byte[maxBufferLen];
                                bytesRead = stream.Read(buffer, 0, maxBufferLen);
                            }

                            //返回本次上传字节数
                            context.Response.Write(stream.Length);
                            context.Response.Flush();
                        }

                        stream.Close();
                        fs.Close();
                    }
                    else
                    {
                        if (i != 1)
                            break;
                        else
                            i = 0;
                    }
                }

                context.Response.Write("Upload Success!");
                context.Response.Flush();
                context.Response.End();
            }
            catch (Exception ex)
            {
            }
            finally
            {
                if (null != stream)
                    stream.Close();
            }
        }

        /// <summary>
        /// 获取实际读取到的字节数组
        /// </summary>
        /// <param name="buffer"></param>
        /// <param name="bytesRead"></param>
        /// <returns></returns>
        private byte[] GetNewBuffer(byte[] buffer, int bytesRead)
        {
            byte[] newBuffer = new byte[bytesRead];
            for (int i = 0; i < bytesRead; i++)
            {
                newBuffer[i] = buffer[i];
            }
            return newBuffer;
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}

完整源码可从http://download.csdn.net/detail/lianchangshuai/4998494下载。