文件（图片生产缩略图）的上传与下载

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文件（图片生产缩略图）的上传与下载

2011年01月19日 ⁄ 综合 ⁄ 共 7238字 ⁄ 字号小中大 ⁄ 评论关闭

一、文件（图片）保存到数据库

//得到用户要上传的文件名

string strFilePathName = loFile.PostedFile.FileName;

string strFileName = Path.GetFileName(strFilePathName);

int FileLength = loFile.PostedFile.ContentLength;

if(FileLength<=0)

return;

try

{//上传文件

Byte[] FileByteArray = new Byte[FileLength]; //图象文件临时储存Byte数组

Stream StreamObject = loFile.PostedFile.InputStream; //建立数据流对像

//读取图象文件数据，FileByteArray为数据储存体，0为数据指针位置、FileLnegth为数据长度

StreamObject.Read(FileByteArray,0,FileLength);

//建立SQL Server链接

string strCon = System.Configuration.ConfigurationSettings.AppSettings["DSN"];

SqlConnection Con = new SqlConnection(strCon);

String SqlCmd = "INSERT INTO ImageStore (ImageData, ImageContentType, ImageDescription, ImageSize) VALUES (@Image, @ContentType, @ImageDescription, @ImageSize)";

SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);

CmdObj.Parameters.Add("@Image",SqlDbType.Binary, FileLength).Value = FileByteArray;

CmdObj.Parameters.Add("@ContentType", SqlDbType.VarChar,50).Value = loFile.PostedFile.ContentType; //记录文件类型

//把其它单表数据记录上传

CmdObj.Parameters.Add("@ImageDescription", SqlDbType.VarChar,200).Value = tbDescription.Text;

//记录文件长度，读取时使用

CmdObj.Parameters.Add("@ImageSize", SqlDbType.BigInt,8).Value = FileLength;

Con.Open();

CmdObj.ExecuteNonQuery();

Con.Close();

//跳转页面

Response.Redirect("ShowAll.aspx");

}

catch

{

}

取出来显示：

int ImgID = Convert.ToInt32(Request.QueryString["ID"]); //ID为图片ID

//建立数据库链接

string strCon = System.Configuration.ConfigurationSettings.AppSettings["DSN"];

SqlConnection Con = new SqlConnection(strCon);

String SqlCmd = "SELECT * FROM ImageStore WHERE ImageID = @ImageID";

SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);

CmdObj.Parameters.Add("@ImageID", SqlDbType.Int).Value = ImgID;

Con.Open();

SqlDataReader SqlReader = CmdObj.ExecuteReader();

SqlReader.Read();

Response.ContentType = (string)SqlReader["ImageContentType"];//设定输出文件类型

//输出图象文件二进制数制

Response.OutputStream.Write((byte[])SqlReader["ImageData"], 0, (int)SqlReader["ImageSize"]);

Response.End();

//也可以保存为图像

// FileStream fs = new FileStream(@"C:\aa.BMP", FileMode.OpenOrCreate, FileAccess.Write);

// fs.Write((byte[])SqlReader["ImageData"], 0,(int)SqlReader["ImageSize"]);

// fs.Close();

Con.Close();

二、文件（图片）保存到硬盘
方法一  /**//// <summary>
2        /// 下载文件
3        /// </summary>
4        /// <param name="filename">文件物理地址</param>
5        protected void DownloadFile(string filename)
6        {
7
8            string saveFileName = "test.xls";
9            int intStart = filename.LastIndexOf("\\")+1;
10            saveFileName = filename.Substring(intStart,filename.Length-intStart);
11
12            System.IO.FileInfo fi=new System.IO.FileInfo(filename);
13            string fileextname=fi.Extension;
14            string DEFAULT_CONTENT_TYPE = "application/unknown";
15            RegistryKey regkey,fileextkey;
16            string filecontenttype;
17            try
18            {
19                regkey=Registry.ClassesRoot;
20                fileextkey=regkey.OpenSubKey(fileextname);
21                filecontenttype=fileextkey.GetValue("Content Type",DEFAULT_CONTENT_TYPE).ToString();
22            }
23            catch
24            {
25                filecontenttype=DEFAULT_CONTENT_TYPE;
26            }
27
28
29            Response.Clear();
30            Response.Charset = "utf-8";
31            Response.Buffer= true;
32            this.EnableViewState = false;
33            Response.ContentEncoding = System.Text.Encoding.UTF8;
34
35            Response.AppendHeader("Content-Disposition","attachment;filename=" + saveFileName);
36            Response.ContentType=filecontenttype;
37
38            Response.WriteFile(filename);
39            Response.Flush();
40            Response.Close();
41
42            Response.End();
43        }
44
方法二
  /**//// <summary>
2        /// 下载文件
3        /// </summary>
4        /// <param name="filename">文件物理地址</param>
5        protected void DownloadFile(string filename)
6        {
7            string saveFileName = "test.xls";
8            int intStart = filename.LastIndexOf("\\")+1;
9            saveFileName = filename.Substring(intStart,filename.Length-intStart);
10
11            Response.Clear();
12            Response.Charset = "utf-8";
13            Response.Buffer= true;
14            this.EnableViewState = false;
15            Response.ContentEncoding = System.Text.Encoding.UTF8;
16
17            Response.AppendHeader("Content-Disposition","attachment;filename=" + saveFileName);
18            Response.WriteFile(filename);
19            Response.Flush();
20            Response.Close();
21
22            Response.End();
23        }
文件的ContentType类型小全