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  • C#中用WebClient.UploadData 方法上载文件数据

    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,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:
    -----------------------------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#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 - 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;
                }

            }
        }
    }

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  • 原文地址:https://www.cnblogs.com/MaxWoods/p/1630921.html
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