文件（图片生产缩略图）的上传与下载

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

string saveFileName = "test.xls";
9

int intStart = filename.LastIndexOf("\\")+1;
10

saveFileName = filename.Substring(intStart,filename.Length-intStart);
11

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

Response.Clear();
30

Response.Charset = "utf-8";
31

Response.Buffer= true;
32

this.EnableViewState = false;
33

Response.ContentEncoding = System.Text.Encoding.UTF8;
34

Response.AppendHeader("Content-Disposition","attachment;filename=" + saveFileName);
36

Response.ContentType=filecontenttype;
37

Response.WriteFile(filename);
39

Response.Flush();
40

Response.Close();
41

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

Response.Clear();
12

Response.Charset = "utf-8";
13

Response.Buffer= true;
14

this.EnableViewState = false;
15

Response.ContentEncoding = System.Text.Encoding.UTF8;
16

Response.AppendHeader("Content-Disposition","attachment;filename=" + saveFileName);
18

Response.WriteFile(filename);
19

Response.Flush();
20

Response.Close();
21

Response.End();
23

}文件的ContentType类型小全

出现提示框

string strFile="F:\\a.doc";//路径根据实际情况而定

if(!System.IO.File.Exists(strFile))

{

Response.Write("<script language='javascript'>alert('对不起，文件不存在！');</script>");

return;

}

Response.Clear();

Response.ClearHeaders();

Response.Charset = "GB2312";

Response.ContentEncoding =System.Text.Encoding.UTF8;

Response.ContentType = "application/octet-stream";

FileInfo fi=new FileInfo(strFile);

Response.AddHeader("Content-Disposition","attachment; filename=" + HttpUtility.UrlEncode(fi.Name)) ;

Response.AddHeader("Content-Length",fi.Length.ToString());

byte[] tmpbyte=new byte[1024*8];

FileStream fs=fi.OpenRead();

int count;

while((count=fs.Read(tmpbyte,0,tmpbyte.Length))>0)

{

Response.BinaryWrite(tmpbyte);

Response.Flush();

}

fs.Close();

Response.End();

直接在浏览器中打开

string strFile="F:\\a.doc";//路径根据实际情况而定

Response.Clear();

Response.ClearHeaders();

Response.Charset = "GB2312";

Response.ContentEncoding =System.Text.Encoding.UTF8;

Response.ContentType = "application/msword";

Response.WriteFile(strFile);

/// <summary>
2

/// 上传图片
3

/// </summary>
4

/// <param name="sender"></param>
5

/// <param name="e"></param>
6

/// <returns>操作结果</returns>
7

private bool ImageUpload(int nWidth,int nHeight)
8

{
9

System.Web.HttpFileCollection files = Request.Files;
10

System.Web.HttpPostedFile pf = files[0];
11

string sOldPath = pf.FileName.ToString();
12

int i = sOldPath.LastIndexOf("\\");
13

string sOldName = sOldPath.Substring(i+1,sOldPath.Length-i-1);
14

//"L"代表大图 && "S"代表缩略图
15

string sTimeNo = System.DateTime.Now.ToString("yyMMddHHmmss");
16

string sNewNameL = "L"+sTimeNo+"_"+sOldName;
17

string sNewNameS = sNewNameL.Replace("L"+sTimeNo,"S"+sTimeNo);
18

string sNewPathL = Server.MapPath("../images/uploadfiles/")+sNewNameL;
19

string sNewPathS = Server.MapPath("../images/uploadfiles/")+sNewNameS;
20

if(System.IO.File.Exists(sNewPathL)||System.IO.File.Exists(sNewPathS))
21

{
22

Page.RegisterStartupScript("FailToUpload","<script>alert('文件名已存在！');</script>");
23

return false;
24

}
25

else
26

{
27

pf.SaveAs(sNewPathL);//保存原图
28

string strContentType = pf.ContentType.ToString();
29

if(strContentType.IndexOf("image/")<0)
30

{
31

Page.RegisterStartupScript("KeyEro","<script>alert('无效的图片格式！');</script>");
32

return false;
33

}
34

else
35

{
36

this.GetThumbNail(sOldPath,strContentType,sNewPathS,nWidth, nHeight);
37

this.Image1.ImageUrl = sNewPathS;
38

return true;
39

}
40

}
41

}
42

/// <summary>
43

/// 生成缩略图
44

/// </summary>
45

/// <param name="FileName">待上传文件的完全限定名</param>
46

/// <param name="strContentType">待上传文件的内容类型</param>
47

/// <param name="path">路径</param>
48

/// <param name="nWidth">宽</param>
49

/// <param name="nHeight">高</param>
50

private void GetThumbNail(string FileName,string strContentType,string path,int nWidth,int nHeight)
51

{
52

System.Drawing.Image oImage;
53

oImage = System.Drawing.Image.FromFile(FileName);
54

oImage = oImage.GetThumbnailImage(nWidth,nHeight,null,IntPtr.Zero);
55

// MemoryStream ms = new MemoryStream();
56

// Response.ContentType = strContentType;
57

// oImage.Save(ms,strContentType);
58

oImage.Save(path,this.GetContenType(strContentType));
59

// ms.WriteTo(Response.OutputStream);
60

}
61

/// <summary>
62

/// 获取保存文件的格式
63

/// </summary>
64

/// <param name="strContentType">待上传文件的内容类型</param>
65

/// <returns>文件格式</returns>
66

private System.Drawing.Imaging.ImageFormat GetContenType(string strContentType)
67

{
68

//只写少数几种格式
69

if(strContentType.ToString().ToLower()== "image/bmp")
70

return System.Drawing.Imaging.ImageFormat.Bmp;
71

else if(strContentType.ToString().ToLower()== "image/gif")
72

return System.Drawing.Imaging.ImageFormat.Gif;
73

else
74

return System.Drawing.Imaging.ImageFormat.Jpeg;
75

}

For example:

Response.ContentType = "image/jpeg";Response.AppendHeader("Content-Disposition","attachment; filename=SailBig.jpg");Response.TransmitFile( Server.MapPath("~/images/sailbig.jpg") );Response.End();

posted on 2005-10-17 17:56 LDAR泄漏检测与修复阅读(1172) 评论(1) 编辑收藏举报

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