[C#]使用WebClient上传文件并同时Post表单数据字段到服务端
转自：http://www.97world.com/archives/2963
之前遇到一个问题，就是使用WebClient上传文件的同时，还要Post表单数据字段，一开始以为WebClient可以直接做到，结果发现如果先Post表单字段，就只能获取到字段及其值，如果先上传文件，也只能获取到上传文件的内容。测试了不少时间才发现WebClient不能这么使用。
Google到相关的解决思路和类，因为发现网上的一些文章不是介绍得太简单就是太复杂，所以这里简单整理一下，既能帮助自己巩固知识，也希望能够帮到大家！如果大家有什么不明白，可以直接留言问我。
关于WebClient上传文件并同时Post表单数据的实现原理，大家可以参考这篇文章http://www.cnblogs.com/goody9807/archive/2007/06/06/773735.html，介绍得非常详细，但是类和实例有些模糊，所以类和实例可以直接参考本文。
HttpRequestClient类Code：
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using System;using System.Collections;using System.Collections.Generic;using System.Linq;using System.IO;using System.Text;using System.Net;namespace Common.Helper{ /// <summary> /// description：http post请求客户端 /// last-modified-date：2012-02-28 /// </summary> public class HttpRequestClient { #region //字段 private ArrayList bytesArray; private Encoding encoding = Encoding.UTF8; private string boundary = String.Empty; #endregion #region //构造方法 public HttpRequestClient() { bytesArray = new ArrayList(); string flag = DateTime.Now.Ticks.ToString("x"); boundary = "---------------------------" + flag; } #endregion #region //方法 /// <summary> /// 合并请求数据 /// </summary> /// <returns></returns> private byte[] MergeContent() { int length = 0; int readLength = 0; string endBoundary = "--" + boundary + "--\r\n"; byte[] endBoundaryBytes = encoding.GetBytes(endBoundary); bytesArray.Add(endBoundaryBytes); foreach (byte[] b in bytesArray) { length += b.Length; } byte[] bytes = new byte[length]; foreach (byte[] b in bytesArray) { b.CopyTo(bytes, readLength); readLength += b.Length; } return bytes; } /// <summary> /// 上传 /// </summary> /// <param name="requestUrl">请求url</param> /// <param name="responseText">响应</param> /// <returns></returns> public bool Upload(String requestUrl, out String responseText) { WebClient webClient = new WebClient(); webClient.Headers.Add("Content-Type", "multipart/form-data; boundary=" + boundary); byte[] responseBytes; byte[] bytes = MergeContent(); try { responseBytes = webClient.UploadData(requestUrl, bytes); responseText = System.Text.Encoding.UTF8.GetString(responseBytes); return true; } catch (WebException ex) { Stream responseStream = ex.Response.GetResponseStream(); responseBytes = new byte[ex.Response.ContentLength]; responseStream.Read(responseBytes, 0, responseBytes.Length); } responseText = System.Text.Encoding.UTF8.GetString(responseBytes); return false; } /// <summary> /// 设置表单数据字段 /// </summary> /// <param name="fieldName">字段名</param> /// <param name="fieldValue">字段值</param> /// <returns></returns> public void SetFieldValue(String fieldName, String fieldValue) { string httpRow = "--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}\r\n"; string httpRowData = String.Format(httpRow, fieldName, fieldValue); bytesArray.Add(encoding.GetBytes(httpRowData)); } /// <summary> /// 设置表单文件数据 /// </summary> /// <param name="fieldName">字段名</param> /// <param name="filename">字段值</param> /// <param name="contentType">内容内型</param> /// <param name="fileBytes">文件字节流</param> /// <returns></returns> public void SetFieldValue(String fieldName, String filename, String contentType, Byte[] fileBytes) { string end = "\r\n"; string httpRow = "--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n"; string httpRowData = String.Format(httpRow, fieldName, filename, contentType); byte[] headerBytes = encoding.GetBytes(httpRowData); byte[] endBytes = encoding.GetBytes(end); byte[] fileDataBytes = new byte[headerBytes.Length + fileBytes.Length + endBytes.Length]; headerBytes.CopyTo(fileDataBytes, 0); fileBytes.CopyTo(fileDataBytes, headerBytes.Length); endBytes.CopyTo(fileDataBytes, headerBytes.Length + fileBytes.Length); bytesArray.Add(fileDataBytes); } #endregion }} |
客户端实例代码：
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string fileFullName=@"c:\test.txt",filedValue="hello_world",responseText = "";FileStream fs = new FileStream(fileFullName, System.IO.FileMode.Open, System.IO.FileAccess.Read);byte[] fileBytes = new byte[fs.Length];fs.Read(fileBytes, 0, fileBytes.Length);fs.Close(); fs.Dispose();HttpRequestClient httpRequestClient = new HttpRequestClient();httpRequestClient.SetFieldValue("key", filedValue);httpRequestClient.SetFieldValue("uploadfile", Path.GetFileName(fileFullName), "application/octet-stream", fileBytes);httpRequestClient.Upload(NormalBotConfig.Instance.GetUploadFileUrl(), out responseText); |
服务端实例代码：
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if (HttpContext.Current.Request.Files.AllKeys.Length > 0){ string filePath = Path.Combine(HttpContext.Current.Server.MapPath("~/"), "UploadFile", DateTime.Now.Year.ToString(), DateTime.Now.Month.ToString(), DateTime.Now.Day.ToString()); if (!Directory.Exists(filePath)) Directory.CreateDirectory(filePath); //这里我直接用索引来获取第一个文件，如果上传了多个文件，可以通过遍历HttpContext.Current.Request.Files.AllKeys取“key值”，再通过HttpContext.Current.Request.Files[“key值”]获取文件 HttpContext.Current.Request.Files[0].SaveAs(Path.Combine(filePath, HttpContext.Current.Request.Files[0].FileName)); string filedValue = HttpContext.Current.Request.Form["key"];} |
使用WebClient或HttpWebRequest模拟上传文件和数据
假如某网站有个表单，例如(url: http://localhost/login.aspx)：
帐号 密码 我们需要在程序中提交数据到这个表单，对于这种表单，我们可以使用 WebClient.UploadData 方法来实现，将所要上传的数据拼成字符即可，程序很简单：string uriString = "http://localhost/login.aspx";// 创建一个新的 WebClient 实例.WebClient myWebClient = new WebClient();string postData = "Username=admin&Password=admin";// 注意这种拼字符串的ContentTypemyWebClient.Headers.Add("Content-Type","application/x-www-form-urlencoded");// 转化成二进制数组byte[] byteArray = Encoding.ASCII.GetBytes(postData);// 上传数据，并获取返回的二进制数据.byte[] responseArray = myWebClient.UploadData(uriString,"POST",byteArray);对于文件上传类的表单，例如(url: http://localhost/uploadFile.aspx)：文件 对于这种表单，我们可以使用String uriString = "http://localhost/uploadFile.aspx";// 创建一个新的 WebClient 实例.WebClient myWebClient = new WebClient();string fileName = @"C:\upload.txt";// 直接上传，并获取返回的二进制数据.byte[] responseArray = myWebClient.UploadFile(uriString,"POST",fileName);还有一种表单，不仅有文字，还有文件，例如(url: http://localhost/uploadData.aspx)：文件名 文件 对于这种表单，似乎前面的两种方法都不能适用，对于第一种方法，不能直接拼字符串，对于第二种，我们只能传文件，重新回到第一个方法，注意参数：public byte[] UploadData( string address, string method, byte[] data);在第一个例子中，是通过拼字符串来得到byte[] data参数值的，对于这种表单显然不行，反过来想想，对于uploadData.aspx这样的程序来说，直接通过网页提交数据，后台所获取到的流是什么样的呢？（在我以前的一篇blog中，曾分析过这个问题：asp无组件上传进度条解决方案），最终的数据如下：-----------------------------7d429871607feContent-Disposition: form-data; name="file1"; filename="G:\homepage.txt"Content-Type: text/plain宝玉：http://www.webuc.net-----------------------------7d429871607feContent-Disposition: form-data; name="filename"default filename-----------------------------7d429871607fe--所以只要拼一个这样的byte[] data数据Post过去，就可以达到同样的效果了。但是一定要注意，对于这种带有文件上传的，其ContentType是不一样的，例如上面的这种，其ContentType为"multipart/form-data; boundary=---------------------------7d429871607fe"。有了ContentType，我们就可以知道boundary(就是上面的"---------------------------7d429871607fe")，知道boundary了我们就可以构造出我们所需要的byte[] data了，最后，不要忘记，把我们构造的ContentType传到WebClient中（例如:webClient.Headers.Add("Content-Type", ContentType);）这样，就可以通过WebClient.UploadData 方法上载文件数据了。具体代码如下：生成二进制数据类的封装using System;using System.Web;using System.IO;using System.Net;using System.Text;using System.Collections;namespace UploadData.Common
{
/**//// <summary>
/// 创建WebClient.UploadData方法所需二进制数组
/// </summary> public class CreateBytes { Encoding encoding = Encoding.UTF8; /**//// <summary> /// 拼接所有的二进制数组为一个数组 /// </summary> /// <param name="byteArrays">数组</param> /// <returns></returns> /// <remarks>加上结束边界</remarks> public byte[] JoinBytes(ArrayList byteArrays) { int length = 0; int readLength = 0; // 加上结束边界 string endBoundary = Boundary + "--\r\n"; //结束边界 byte[] endBoundaryBytes = encoding.GetBytes(endBoundary); byteArrays.Add(endBoundaryBytes); foreach(byte[] b in byteArrays) { length += b.Length; } byte[] bytes = new byte[length]; // 遍历复制 // foreach(byte[] b in byteArrays) { b.CopyTo(bytes, readLength); readLength += b.Length; } return bytes; } public bool UploadData(string uploadUrl, byte[] bytes, out byte[] responseBytes) { WebClient webClient = new WebClient(); webClient.Headers.Add("Content-Type", ContentType); try { responseBytes = webClient.UploadData(uploadUrl, bytes); return true; } catch (WebException ex) { Stream resp = ex.Response.GetResponseStream(); responseBytes = new byte[ex.Response.ContentLength]; resp.Read(responseBytes, 0, responseBytes.Length); } return false; } /**//// <summary> /// 获取普通表单区域二进制数组 /// </summary> /// <param name="fieldName">表单名</param> /// <param name="fieldValue">表单值</param> /// <returns></returns> /// <remarks> /// -----------------------------7d52ee27210a3c\r\nContent-Disposition: form-data; name=\"表单名\"\r\n\r\n表单值\r\n /// </remarks> public byte[] CreateFieldData(string fieldName, string fieldValue) { string textTemplate = Boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}\r\n"; string text = String.Format(textTemplate, fieldName, fieldValue); byte[] bytes = encoding.GetBytes(text); return bytes; } /**//// <summary> /// 获取文件上传表单区域二进制数组 /// </summary> /// <param name="fieldName">表单名</param> /// <param name="filename">文件名</param> /// <param name="contentType">文件类型</param> /// <param name="contentLength">文件长度</param> /// <param name="stream">文件流</param> /// <returns>二进制数组</returns> public byte[] CreateFieldData(string fieldName, string filename,string contentType, byte[] fileBytes) { string end = "\r\n"; string textTemplate = Boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n"; // 头数据 string data = String.Format(textTemplate, fieldName, filename, contentType); byte[] bytes = encoding.GetBytes(data); // 尾数据 byte[] endBytes = encoding.GetBytes(end); // 合成后的数组 byte[] fieldData = new byte[bytes.Length + fileBytes.Length + endBytes.Length]; bytes.CopyTo(fieldData, 0); // 头数据 fileBytes.CopyTo(fieldData, bytes.Length); // 文件的二进制数据 endBytes.CopyTo(fieldData, bytes.Length + fileBytes.Length); // \r\n return fieldData; }
属性属性 }
}在Winform中调用using System;using System.Drawing;using System.Collections;using System.ComponentModel;using System.Windows.Forms;using System.Data;using UploadData.Common;using System.IO;namespace UploadDataWin{ /**//// <summary> /// frmUpload 的摘要说明。 /// </summary> public class frmUpload : System.Windows.Forms.Form { private System.Windows.Forms.Label lblAmigoToken; private System.Windows.Forms.TextBox txtAmigoToken; private System.Windows.Forms.Label lblFilename; private System.Windows.Forms.TextBox txtFilename; private System.Windows.Forms.Button btnBrowse; private System.Windows.Forms.TextBox txtFileData; private System.Windows.Forms.Label lblFileData; private System.Windows.Forms.Button btnUpload; private System.Windows.Forms.OpenFileDialog openFileDialog1; private System.Windows.Forms.TextBox txtResponse; /**//// <summary> /// 必需的设计器变量。 /// </summary> private System.ComponentModel.Container components = null; public frmUpload() { // // Windows 窗体设计器支持所必需的 // InitializeComponent(); // // TODO: 在 InitializeComponent 调用后添加任何构造函数代码 // } /**//// <summary> /// 清理所有正在使用的资源。 /// </summary> protected override void Dispose( bool disposing ) { if( disposing ) { if (components != null) { components.Dispose(); } } base.Dispose( disposing ); } Windows 窗体设计器生成的代码#region Windows 窗体设计器生成的代码 /**//// <summary> /// 设计器支持所需的方法 - 不要使用代码编辑器修改 /// 此方法的内容。 /// </summary> private void InitializeComponent() { this.lblAmigoToken = new System.Windows.Forms.Label(); this.txtAmigoToken = new System.Windows.Forms.TextBox(); this.lblFilename = new System.Windows.Forms.Label(); this.txtFilename = new System.Windows.Forms.TextBox(); this.btnBrowse = new System.Windows.Forms.Button(); this.txtFileData = new System.Windows.Forms.TextBox(); this.lblFileData = new System.Windows.Forms.Label(); this.btnUpload = new System.Windows.Forms.Button(); this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog(); this.txtResponse = new System.Windows.Forms.TextBox(); this.SuspendLayout(); // // lblAmigoToken // this.lblAmigoToken.Location = new System.Drawing.Point(40, 48); this.lblAmigoToken.Name = "lblAmigoToken"; this.lblAmigoToken.Size = new System.Drawing.Size(72, 23); this.lblAmigoToken.TabIndex = 0; this.lblAmigoToken.Text = "AmigoToken"; // // txtAmigoToken // this.txtAmigoToken.Location = new System.Drawing.Point(120, 48); this.txtAmigoToken.Name = "txtAmigoToken"; this.txtAmigoToken.Size = new System.Drawing.Size(248, 21); this.txtAmigoToken.TabIndex = 1; this.txtAmigoToken.Text = ""; // // lblFilename // this.lblFilename.Location = new System.Drawing.Point(40, 96); this.lblFilename.Name = "lblFilename"; this.lblFilename.Size = new System.Drawing.Size(80, 23); this.lblFilename.TabIndex = 2; this.lblFilename.Text = "Filename"; // // txtFilename // this.txtFilename.Location = new System.Drawing.Point(120, 96); this.txtFilename.Name = "txtFilename"; this.txtFilename.Size = new System.Drawing.Size(248, 21); this.txtFilename.TabIndex = 3; this.txtFilename.Text = ""; // // btnBrowse // this.btnBrowse.Location = new System.Drawing.Point(296, 144); this.btnBrowse.Name = "btnBrowse"; this.btnBrowse.TabIndex = 4; this.btnBrowse.Text = "浏览"; this.btnBrowse.Click += new System.EventHandler(this.btnBrowse_Click); // // txtFileData // this.txtFileData.Location = new System.Drawing.Point(120, 144); this.txtFileData.Name = "txtFileData"; this.txtFileData.Size = new System.Drawing.Size(168, 21); this.txtFileData.TabIndex = 5; this.txtFileData.Text = ""; // // lblFileData // this.lblFileData.Location = new System.Drawing.Point(40, 144); this.lblFileData.Name = "lblFileData"; this.lblFileData.Size = new System.Drawing.Size(72, 23); this.lblFileData.TabIndex = 6; this.lblFileData.Text = "FileData"; // // btnUpload // this.btnUpload.Location = new System.Drawing.Point(48, 184); this.btnUpload.Name = "btnUpload"; this.btnUpload.TabIndex = 7; this.btnUpload.Text = "Upload"; this.btnUpload.Click += new System.EventHandler(this.btnUpload_Click); // // txtResponse // this.txtResponse.Location = new System.Drawing.Point(136, 184); this.txtResponse.Multiline = true; this.txtResponse.Name = "txtResponse"; this.txtResponse.Size = new System.Drawing.Size(248, 72); this.txtResponse.TabIndex = 8; this.txtResponse.Text = ""; // // frmUpload // this.AutoScaleBaseSize = new System.Drawing.Size(6, 14); this.ClientSize = new System.Drawing.Size(400, 269); this.Controls.Add(this.txtResponse); this.Controls.Add(this.btnUpload); this.Controls.Add(this.lblFileData); this.Controls.Add(this.txtFileData); this.Controls.Add(this.btnBrowse); this.Controls.Add(this.txtFilename); this.Controls.Add(this.lblFilename); this.Controls.Add(this.txtAmigoToken); this.Controls.Add(this.lblAmigoToken); this.Name = "frmUpload"; this.Text = "frmUpload"; this.ResumeLayout(false); } #endregion /**//// <summary> /// 应用程序的主入口点。 /// </summary> [STAThread] static void Main() { Application.Run(new frmUpload()); } private void btnUpload_Click(object sender, System.EventArgs e) { // 非空检验 if (txtAmigoToken.Text.Trim() == "" || txtFilename.Text == "" || txtFileData.Text.Trim() == "") { MessageBox.Show("Please fill data"); return; } // 所要上传的文件路径 string path = txtFileData.Text.Trim(); // 检查文件是否存在 if (!File.Exists(path)) { MessageBox.Show("{0} does not exist!", path); return; } // 读文件流 FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read); // 这部分需要完善 string ContentType = "application/octet-stream"; byte[] fileBytes = new byte[fs.Length]; fs.Read(fileBytes, 0, Convert.ToInt32(fs.Length)); // 生成需要上传的二进制数组 CreateBytes cb = new CreateBytes(); // 所有表单数据 ArrayList bytesArray = new ArrayList(); // 普通表单 bytesArray.Add(cb.CreateFieldData("FileName", txtFilename.Text)); bytesArray.Add(cb.CreateFieldData("AmigoToken", txtAmigoToken.Text)); // 文件表单 bytesArray.Add(cb.CreateFieldData("FileData", path , ContentType, fileBytes)); // 合成所有表单并生成二进制数组 byte[] bytes = cb.JoinBytes(bytesArray); // 返回的内容 byte[] responseBytes; // 上传到指定Url bool uploaded = cb.UploadData("http://localhost/UploadData/UploadAvatar.aspx", bytes, out responseBytes); // 将返回的内容输出到文件 using (FileStream file = new FileStream(@"c:\response.text", FileMode.Create, FileAccess.Write, FileShare.Read)) { file.Write(responseBytes, 0, responseBytes.Length); } txtResponse.Text = System.Text.Encoding.UTF8.GetString(responseBytes); } private void btnBrowse_Click(object sender, System.EventArgs e) { if(openFileDialog1.ShowDialog() == DialogResult.OK) { txtFileData.Text = openFileDialog1.FileName; } } }}
