关于图片上传及下载的问题

Question

我想将图片以二进制流的形式上传至数据库中，然后再读出来。请教各位：如何做，能否提供些代码

Answer 1

  //写入图片到数据库中
  private void WriteImage()
  {
   SqlCommand comm = conn.CreateCommand();
   comm.CommandText = "insert into images(image,type) values(@image,@type)";
   comm.CommandType = CommandType.Text;
   SqlParameter param = comm.Parameters.Add("@image",SqlDbType.Image);
   param.Value = ReadFile();
   param = comm.Parameters.Add("@type",SqlDbType.NVarChar);
   param.Value = GetContentType(new FileInfo(fileName).Extension.Remove(0,1));   if(comm.ExecuteNonQuery() == 1)
    Response.Write("Successful");
   else
    Response.Write("Fail");
   
   conn.Close();
  }  //获取图片的后缀名
  private string GetContentType(string extension)
  {
   string type = "";   if(extension.Equals("jpg") || extension.Equals("JPG"))
    type = "jpeg";
   else
    type = extension;   return "image/"+type;
  }  //从数据库中读取图片
  private void ReadImage()
  {
   SqlCommand comm = conn.CreateCommand();
   comm.CommandText = "select image,type from images";
   comm.CommandType = CommandType.Text;   SqlDataReader reader = comm.ExecuteReader();
   while(reader.Read())
   {
    Response.ContentType = reader["type"].ToString();//读写类型  一定要设置 否则浏览器会当作文本输出
    Response.BinaryWrite((byte[])reader["image"]);//图片数据
   }   Response.Write("Successful");
   Response.End();   conn.Close();
  }本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/21aspnet/archive/2004/10/26/153202.aspx

Answer 2

//得到文件名
  private string GetFile()
  {
   HttpPostedFile file = File1.PostedFile;
   fileName = file.FileName;   return fileName;
  }  //读取文件内容
  private byte[] ReadFile()
  {
   FileStream file = File.OpenRead(GetFile());
   byte[] content = new byte[file.Length];
   file.Read(content,0,content.Length);
   file.Close();
   
   return content;
  }  //连接数据库
  private void ConnectDB()
  {
   string connStr = "Initial Catalog=;Data Source=;User ID=;Password=;";
   conn = new SqlConnection(connStr);
   conn.Open();
  }

Answer 3

          If File1.PostedFile.ContentLength > 0 Then            sFileName = pf.GetFileName(File1.PostedFile.FileName)
            sFileType = File1.PostedFile.ContentType
            sFilePath = ".." '指定存在..目录            If Left(sFileType, 5) <> "image" Then
                 '所要上传的文件不是图片，请重新选取！
            End If            File1.PostedFile.SaveAs(sFilePath)
        End IfResponse.ContentType = "image/*"
Response.BinaryWrite(dt.Rows(0)("FileCont"))

Answer 4

存：
string picturename = FileUpload1.FileName;
            string lastname = picturename.Substring(picturename.LastIndexOf(".") + 1);
            if (lastname.ToLower() == "bmp" || lastname.ToLower() == "jpg" || lastname.ToLower() == "gif")
            {
                try
                {
                    SqlConnection conn = new SqlConnection();
                    conn.ConnectionString = "Data Source=localhost;Initial Catalog=zcpd;Integrated Security=True";
                    conn.Open();
                    int len = FileUpload1.PostedFile.ContentLength;
                    Byte[] picturedata = new Byte[len];
                    HttpPostedFile htp = FileUpload1.PostedFile;
                    Stream srm = htp.InputStream;
                    srm.Read(picturedata, 0, len);
                    SqlCommand cmd = new SqlCommand();
                    cmd.CommandText = "";
                    cmd.Connection = conn;
                    cmd.Parameters.Add("@picturedata", SqlDbType.Image);
                    cmd.Parameters["@picturedata"].Value = picturedata;
                    int affect = cmd.ExecuteNonQuery();
                    conn.Close();
                    conn.Dispose();
                    if (affect == 1)
                        lblMessage.Text = "上报成功！";
                    else
                        lblMessage.Text = "上报失败！";
                }
                catch (SqlException ex)
                {
                    lblMessage.Text = "出错";
                }
            }
            else
                lblMessage.Text = "上传照片文件格式不对！";
取：
SqlConnection conn = new SqlConnection();
        conn.ConnectionString = "Data Source=localhost;Initial Catalog=zcpd;Integrated Security=True";
        conn.Open();
        SqlCommand cmd = new SqlCommand();
        cmd.CommandText = "";
        cmd.Connection = conn;
        SqlDataReader sdr = cmd.ExecuteReader();
        sdr.Read();
        Response.BinaryWrite((Byte[])sdr["zhaopian"]);
        sdr.Close();
        conn.Close();
        conn.Dispose();

Answer 5

基本上就是楼上各位讲的咯
使用的是IO的几个stream类

Answer 6

用bitmap,memorystream序列化也可以.
楼上的方法也没有问题

Answer 7

二进制存进数据库If FileUpload1.HasFile Then
            Dim FileExt As String = System.IO.Path.GetExtension(FileUpload1.FileName)
            Dim ContentType As String = FileUpload1.PostedFile.ContentType
            Dim fileData As Byte() = FileUpload1.FileBytes
            Dim sql As String
            sql = "INSERT INTO UserList (Title,ContentType,Photo) Values(@Title,@ContentType,@Photo)"
            Dim ConnectionString As String = "Data Source=localhost;Initial Catalog=aaa;Integrated Security=True"
            Dim cn As SqlConnection = New SqlConnection(ConnectionString)
            cn.Open()
            Dim cmd As SqlCommand = New SqlCommand(sql, cn)
            cmd.Parameters.Add("@Title", System.Data.SqlDbType.NVarChar)
            cmd.Parameters.Add("@ContentType", System.Data.SqlDbType.VarChar)
            cmd.Parameters.Add("@Photo", System.Data.SqlDbType.Image)
            cmd.Parameters("@Title").Value = TextBox1.Text
            cmd.Parameters("@ContentType").Value = ContentType
            cmd.Parameters("@Photo").Value = fileData
            cmd.ExecuteNonQuery()
            cn.Close()
            cn.Dispose()
        End If取图 Response.BinaryWrite(CType(myDataReader("Photo"), Byte()))

Answer 8

byte[] MyData = new byte[0];
using (SqlConnection conn = new SqlConnection(sqlconnstr))
        {
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandText = "select * from Tb_img";
            SqlDataReader sdr = cmd.ExecuteReader();
            sdr.Read();
            MyData = (byte[])sdr["ImgFile"];
            Response.ContentType = "image/gif";
            Response.BinaryWrite(MyData);
            conn.Close();
        }HttpPostedFile UpFile = UP_File.PostedFile;  
 FileLength = UpFile.ContentLength;
 Byte[] FileByteArray = new byte[FileLength];  
 Stream StreamObj = UpFile.InputStream;
 StreamObj.Read(FileByteArray, 0, FileLength);
 using (SqlConnection conn = new SqlConnection(sqlconnstr))
{    
 String SqlCmd = "INSERT INTO Tb_Img(imgFile,ImageContentType,ImageDescription,ImageSize) VALUES (@Image,@ContentType,@ImageDescription,@ImageSize)";
                SqlCommand Cmd = new SqlCommand(SqlCmd, Con);
                Cmd.Parameters.Add("@ImgFile", SqlDbType.Binary, FileLength).Value = FileByteArray;
                Cmd.Parameters.Add("@ContentType", SqlDbType.VarChar, 50).Value = UpFile.ContentType;           
                Cmd.Parameters.Add("@ImageDescription", SqlDbType.VarChar, 200).Value = txtDescription.Text;    
                Cmd.Parameters.Add("@ImageSize", SqlDbType.BigInt, 8).Value = UpFile.ContentLength;
                Cmd.ExecuteNonQuery();
       }

Answer 9

要是还有问题的话，去cnblogs去搜一下。那边的代码多

Answer 10

http://download.csdn.net/down/475573/kthree