在Asp.net用WebClient.UploadData 方法来上载文件数据

我们先看一个例子:
  假如某网站有个表单(Forms),例如(http://aspx1.com):
  帐号
  密码
 
  我们需要在程序中提交数据到这个表单(Forms),对于这种表单(Forms),我们可以使用 WebClient.UploadData 方法(Methods)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://aspx1.com";
  // 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ContentType
  myWebClient.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(Forms),例如(url: http://localhost/uploadFile.aspx):
  文件
 
  对于这种表单(Forms),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(Forms),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(Forms),似乎前面的两种方法(Methods)都不能适用,对于第一种方法(Methods),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(Methods),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(Forms)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:
 
  -----------------------------7d429871607fe
  Content-Disposition: form-data; name="file1"; filename="G:\homepage.txt"
  Content-Type: text/plain
  宝玉:http://www.webuc.net
  -----------------------------7d429871607fe
  Content-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(Methods)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(Methods)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(Forms)区域二进制数组
  /// </summary>
  /// <param name="fieldName">表单(Forms)名</param>
  /// <param name="fieldValue">表单(Forms)值</param>
  /// <returns></returns>
  /// <remarks>
  /// -----------------------------7d52ee27210a3c\r\nContent-Disposition: form-data; name=\"表单(Forms)名\"\r\n\r\n表单(Forms)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(Forms)区域二进制数组
  /// </summary>
  /// <param name="fieldName">表单(Forms)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#region 属性
  public string Boundary
  ...{
  get
  ...{
  string[] bArray, ctArray;
  string contentType = ContentType;
  ctArray = contentType.Split(';');
  if (ctArray[0].Trim().ToLower() == "multipart/form-data")
  ...{
  bArray = ctArray[1].Split('=');
  return "--" + bArray[1];
  }
  return null;
  }
  }
 
  public string ContentType
  ...{
  get ...{
  if (HttpContext.Current == null)
  ...{
  return "multipart/form-data; boundary=---------------------------7d5b915500cee";
  }
  return HttpContext.Current.Request.ContentType;
  }
  }
  #endregion
  }
  }
 
 
  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(Methods) - 不要使用代码编辑器修改
  /// 此方法(Methods)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 C;
  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(Forms)数据
  ArrayList bytesArray = new ArrayList();
  // 普通表单(Forms)
  bytesArray.Add(cb.CreateFieldData("FileName", txtFilename.Text));
  bytesArray.Add(cb.CreateFieldData("AmigoToken", txtAmigoToken.Text));
  // 文件表单(Forms)
  bytesArray.Add(cb.CreateFieldData("FileData", path
  , ContentType, fileBytes));
 
  // 合成所有表单(Forms)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;
  }
 
  }
  }
  }
 
    宝玉的blog: http://blog.joycode.com/dotey
最后编辑aspx1 最后编辑于 2008-01-23 20:50:41
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