穩紮穩打Silverlight(20) - 2.0通信之WebClient, 以字元串的形式上傳/下載下傳資料, 以流的方式上傳/下載下傳資料

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穩紮穩打Silverlight(20) - 2.0通信之WebClient, 以字元串的形式上傳/下載下傳資料, 以流的方式上傳/下載下傳資料

介紹

Silverlight 2.0 詳解WebClient，以字元串的形式上傳、下載下傳資料；以流的方式上傳、下載下傳資料

    WebClient - 将資料發送到指定的 URI，或者從指定的 URI 接收資料的類

        DownloadStringAsync(Uri address, Object userToken) - 以字元串的形式下載下傳指定的 URI 的資源

        UploadStringAsync(Uri address, string data) - 以字元串的形式上傳資料到指定的 URI。所使用的 HTTP 方法預設為 POST

        OpenReadAsync(Uri address, Object userToken) - 以流的形式下載下傳指定的 URI 的資源

        OpenWriteAsync(Uri address, string method, Object userToken) - 打開流以使用指定的方法向指定的 URI 寫入資料

線上DEMO

示例

1、以字元串的形式和流的形式下載下傳資料

WebClientDownload.xaml

&lt;UserControl x:Class="Silverlight20.Communication.WebClientDownload" 

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"&gt; 

        &lt;StackPanel HorizontalAlignment="Left" Orientation="Horizontal"&gt; 

                &lt;StackPanel Margin="5" Width="200"&gt; 

                        &lt;TextBox x:Name="lblMsgString" Margin="5" /&gt; 

                        &lt;ProgressBar x:Name="progressBarString" Height="20" Margin="5" Minimum="0" Maximum="100" /&gt; 

                &lt;/StackPanel&gt; 

                        &lt;TextBox x:Name="lblMsgStream" Margin="5" /&gt; 

                        &lt;ProgressBar x:Name="progressBarStream" Height="20" Margin="5" Minimum="0" Maximum="100" /&gt; 

                        &lt;Image x:Name="img" Margin="5" /&gt; 

        &lt;/StackPanel&gt; 

&lt;/UserControl&gt;

WebClientDownload.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.IO; 

namespace Silverlight20.Communication 

{ 

        public partial class WebClientDownload : UserControl 

        { 

                // 用于示範以字元串的形式下載下傳資料 

                string _urlString = "http://localhost/Files/Demo.zip"; 

                // 用于示範以流的形式下載下傳資料 

                string _urlStream = "http://localhost/Files/Logo.png"; 

                public WebClientDownload() 

                { 

                        InitializeComponent(); 

                        // 示範字元串式下載下傳 

                        DownloadStringDemo(); 

                        // 示範流式下載下傳 

                        DownloadStreamDemo(); 

                } 

                /// &lt;summary&gt; 

                /// 示範字元串式下載下傳 

                /// &lt;/summary&gt; 

                void DownloadStringDemo() 

                        Uri uri = new Uri(_urlString, UriKind.Absolute); 

                        /*    

                         * WebClient - 将資料發送到指定的 URI，或者從指定的 URI 接收資料的類 

                         *         DownloadStringCompleted - 下載下傳資料完畢後（包括取消操作及有錯誤發生時）所觸發的事件

                         *         DownloadProgressChanged - 下載下傳資料過程中所觸發的事件。正在下載下傳或下載下傳完全部資料後會觸發 

                         *         DownloadStringAsync(Uri address, Object userToken) - 以字元串的形式下載下傳指定的 URI 的資源 

                         *                 Uri address - 需要下載下傳的資源位址 

                         *                 Object userToken - 使用者辨別 

                         */ 

                        System.Net.WebClient clientDownloadString = new System.Net.WebClient(); 

                        clientDownloadString.DownloadStringCompleted += new DownloadStringCompletedEventHandler(clientDownloadString_DownloadStringCompleted); 

                        clientDownloadString.DownloadProgressChanged += new DownloadProgressChangedEventHandler(clientDownloadString_DownloadProgressChanged); 

                        clientDownloadString.DownloadStringAsync(uri, "userToken"); 

                void clientDownloadString_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e) 

                        /* 

                         * DownloadProgressChangedEventArgs.ProgressPercentage - 下載下傳完成的百分比 

                         * DownloadProgressChangedEventArgs.BytesReceived - 目前收到的位元組數 

                         * DownloadProgressChangedEventArgs.TotalBytesToReceive - 總共需要下載下傳的位元組數 

                         * DownloadProgressChangedEventArgs.UserState - 使用者辨別 

                        lblMsgString.Text = string.Format("下載下傳完成的百分比：{0}\r\n目前收到的位元組數：{1}\r\n總共需要下載下傳的位元組數：{2}\r\n", 

                                e.ProgressPercentage.ToString() + "%", 

                                e.BytesReceived.ToString(), 

                                e.TotalBytesToReceive.ToString()); 

                        progressBarString.Value = (double)e.ProgressPercentage; 

                void clientDownloadString_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e) 

                         * DownloadStringCompletedEventArgs.Error - 該異步操作期間是否發生了錯誤 

                         * DownloadStringCompletedEventArgs.Cancelled - 該異步操作是否已被取消 

                         * DownloadStringCompletedEventArgs.Result - 下載下傳後的字元串類型的資料 

                         * DownloadStringCompletedEventArgs.UserState - 使用者辨別 

                        if (e.Error != null) 

                        { 

                                lblMsgString.Text += e.Error.ToString(); 

                                return; 

                        } 

                        if (e.Cancelled != true) 

                                lblMsgString.Text += string.Format("使用者辨別：{0}", e.UserState.ToString()); 

                /// 示範流式下載下傳 

                void DownloadStreamDemo() 

                        Uri uri = new Uri(_urlStream, UriKind.Absolute); 

                         *         IsBusy - 指定的web請求是否正在進行中 

                         *         CancelAsync() - 取消指定的異步操作    

                         *         OpenReadCompleted - 資料讀取完畢後（包括取消操作及有錯誤發生時）所觸發的事件。流的方式 

                         *         OpenReadAsync(Uri address, Object userToken) - 以流的形式下載下傳指定的 URI 的資源 

                        System.Net.WebClient clientDownloadStream = new System.Net.WebClient(); 

                        if (clientDownloadStream.IsBusy) 

                                clientDownloadStream.CancelAsync(); 

                        clientDownloadStream.OpenReadCompleted += new OpenReadCompletedEventHandler(clientDownloadStream_OpenReadCompleted); 

                        clientDownloadStream.DownloadProgressChanged += new DownloadProgressChangedEventHandler(clientDownloadStream_DownloadProgressChanged); 

                        clientDownloadStream.OpenReadAsync(uri); 

                void clientDownloadStream_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e) 

                        progressBarStream.Value = (double)e.ProgressPercentage; 

                void clientDownloadStream_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e) 

                         * OpenReadCompletedEventArgs.Error - 該異步操作期間是否發生了錯誤 

                         * OpenReadCompletedEventArgs.Cancelled - 該異步操作是否已被取消 

                         * OpenReadCompletedEventArgs.Result - 下載下傳後的 Stream 類型的資料 

                         * OpenReadCompletedEventArgs.UserState - 使用者辨別 

                                lblMsgStream.Text += e.Error.ToString(); 

                                System.Windows.Media.Imaging.BitmapImage imageSource = new System.Windows.Media.Imaging.BitmapImage(); 

                                imageSource.SetSource(e.Result); 

                                img.Source = imageSource; 

        } 

}

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