图片保存到数据库的小程序

应一位网友要求，做了一个将图片保存到数据库和从数据库读取图片的小程序。 源码如下： using  System; using  System.Collections.Generic; using  System.ComponentModel; using  System.Data; using  System.Drawing; using  System.Text; using  System.Windows.Forms; using  System.Data.Sql; using  System.Data.SqlClient; using  System.IO; namespace  ImageToDB {      public   partial   class  UserEdit : Form     {          public  UserEdit()         {             InitializeComponent();         }          private   void  UserEdit_Load( object  sender, EventArgs e)         {             LoadNextUser();         }          string  strConn  =   " Data Source=wangyang\\SQLEXPRESS;Initial Catalog=test;Persist Security Info=True;User ID=uap;Password=uap " ;          string  strGetTopOne  =   " select top 1 * from users  " ;          ///   <summary>          ///  保存按钮事件          ///   </summary>          ///   <param name="sender"></param>          ///   <param name="e"></param>          private   void  button2_Click( object  sender, EventArgs e)         {              if  (txtUserID.Text  ==   ""   ||  txtUserID.Text  ==   string .Empty)             {                  // 新增                  if  (txtUserName.Text  ==   ""   ||  txtImagePath.Text  ==   "" )                 {                     MessageBox.Show( " 用户名和图片不能为空！ " );                      return ;                 }                  // 这里看如何将图片保存到数据库的。                 FileStream fs  =  File.OpenRead(txtImagePath.Text);                  byte [] imageb  =   new   byte [fs.Length];                 fs.Read(imageb,  0 , imageb.Length);                 fs.Close();                  string  strSQL  =   " insert into Users(UserName,UserImage)values(@UserName,@UserImage) " ;                 SqlConnection con  =   new  SqlConnection(strConn);                 SqlCommand com3  =   new  SqlCommand(strSQL, con);                 com3.Parameters.Add( " @UserName " , SqlDbType.VarChar).Value  =  txtUserName.Text;                 com3.Parameters.Add( " @UserImage " , SqlDbType.Image).Value  =  imageb;                  if  (com3.Connection.State  ==  ConnectionState.Closed)                     com3.Connection.Open();                  try                 {                     com3.ExecuteNonQuery();                     MessageBox.Show( " 新增用户成功！ " );                 }                  catch                 {                     MessageBox.Show( " 新增用户失败！ " );                 }                  finally                 { com3.Connection.Close(); }             }              else             {                  // 修改                  // 这里看如何将图片保存到数据库的。                  string  strSQL  =   " update users set username=@UserName " ;                  if  (txtImagePath.Text  !=   "" )                     strSQL  +=   " ,userimage=@UserImage " ;                 SqlConnection con  =   new  SqlConnection(strConn);                 SqlCommand com3  =   new  SqlCommand(strSQL, con);                 com3.Parameters.Add( " @UserName " , SqlDbType.VarChar).Value  =  txtUserName.Text;                  if  (txtImagePath.Text  !=   "" )                 {                     FileStream fs  =  File.OpenRead(txtImagePath.Text);                      byte [] imageb  =   new   byte [fs.Length];                     fs.Read(imageb,  0 , imageb.Length);                     fs.Close();                     com3.Parameters.Add( " @UserImage " , SqlDbType.Image).Value  =  imageb;                 }                  if  (com3.Connection.State  ==  ConnectionState.Closed)                     com3.Connection.Open();                  try                 {                     com3.ExecuteNonQuery();                     MessageBox.Show( " 修改用户成功！ " );                 }                  catch                 {                     MessageBox.Show( " 修改用户失败！ " );                  }                  finally                 { com3.Connection.Close(); }             }         }          ///   <summary>          ///  下一位。          ///   </summary>          ///   <param name="sender"></param>          ///   <param name="e"></param>          private   void  button4_Click( object  sender, EventArgs e)         {              string  preUserID  =  txtUserID.Text;             LoadNextUser();              if  (txtUserID.Text  ==  preUserID)                 MessageBox.Show( " 已经是最后一位用户！ " );         }          ///   <summary>          ///  清空。          ///   </summary>          ///   <param name="sender"></param>          ///   <param name="e"></param>          private   void  button1_Click( object  sender, EventArgs e)         {             txtUserID.Text  =   "" ;             txtUserName.Text  =   "" ;             txtImagePath.Text  =   "" ;             pictureBox1.Image  =   null ;         }          ///   <summary>          ///  选择图片。          ///   </summary>          ///   <param name="sender"></param>          ///   <param name="e"></param>          private   void  btOpenImage_Click( object  sender, EventArgs e)         {             openFileDialog1.Filter  =   " JPEG|*.jpg|GIF|*.gif " ;              if  (openFileDialog1.ShowDialog()  ==  DialogResult.OK)             {                 txtImagePath.Text  =  openFileDialog1.FileName;                 FileStream fs  =  File.OpenRead(txtImagePath.Text);                  byte [] imageb  =   new   byte [fs.Length];                 fs.Read(imageb,  0 , imageb.Length);                 fs.Close();                 MemoryStream memStream  =   new  MemoryStream(imageb);                  try                 {                     Bitmap myimge  =   new  Bitmap(memStream);                      this .pictureBox1.Image  =  myimge;                 }                  catch                 {                 }             }         }          ///   <summary>          ///  从数据库中读取下一位用户的信息。如果参数为空则读取第一条信息。          ///   </summary>          ///   <param name="PreUserID"></param>          ///   <returns></returns>          public  DataTable GetTopOneUser( string  filter)         {             strGetTopOne  =   " select top 1 * from users  " ;              if  (filter  !=   ""   &&  filter  !=   string .Empty)                 strGetTopOne  +=  filter;             SqlConnection con  =   new  SqlConnection(strConn);             SqlCommand com  =   new  SqlCommand(strGetTopOne, con);              if  (con.State  ==  ConnectionState.Closed)                 con.Open();             SqlDataAdapter da  =   new  SqlDataAdapter(com);             DataSet ds  =   new  DataSet();             da.Fill(ds,  " UserTable " );              if  (ds  !=   null   &&  ds.Tables.Count  >   0 )                  return  ds.Tables[ 0 ];              else                  return   null ;         }          ///   <summary>          ///  加载下一位用户信息          ///   </summary>          public   void  LoadNextUser()         {              // 这里看如何将数据库图片读出来              string  filter  = "" ;              if  (txtUserID.Text  !=   "" )                 filter  =   "  where userid> "   +  txtUserID.Text;             DataTable dt  =  GetTopOneUser(filter);              if  (dt.Rows.Count  ==   0 )                  return ;             DataRow dr  =  dt.Rows[ 0 ];             txtUserID.Text  =  dr[ " UserID " ].ToString();             txtUserName.Text  =  dr[ " UserName " ].ToString();              byte [] imageb  =  ( byte [])dr[ " UserImage " ];             MemoryStream memStream  =   new  MemoryStream(imageb);              try             {                 Bitmap myimge  =   new  Bitmap(memStream);                  this .pictureBox1.Image  =  myimge;             }              catch             {             }         }          ///   <summary>          ///  加载上一位用户信息          ///   </summary>          public   void  LoadPreUser()         {              string  filter  =   "" ;              if  (txtUserID.Text  !=   "" )                 filter  =   "  where userid< "   +  txtUserID.Text + "  order by Userid desc " ;             DataTable dt  =  GetTopOneUser(filter);              if  (dt.Rows.Count  ==   0 )                  return ;             DataRow dr  =  dt.Rows[ 0 ];             txtUserID.Text  =  dr[ " UserID " ].ToString();             txtUserName.Text  =  dr[ " UserName " ].ToString();              byte [] imageb  =  ( byte [])dr[ " UserImage " ];             MemoryStream memStream  =   new  MemoryStream(imageb);              try             {                 Bitmap myimge  =   new  Bitmap(memStream);                  this .pictureBox1.Image  =  myimge;             }              catch             {             }         }          ///   <summary>          ///  关闭。          ///   </summary>          ///   <param name="sender"></param>          ///   <param name="e"></param>          private   void  button3_Click( object  sender, EventArgs e)         {              this .Close();         }          ///   <summary>          ///  上一位          ///   </summary>          ///   <param name="sender"></param>          ///   <param name="e"></param>          private   void  button5_Click( object  sender, EventArgs e)         {              string  preUserID  =  txtUserID.Text;             LoadPreUser();              if  (txtUserID.Text  ==  preUserID)                 MessageBox.Show( " 已经是最前一位用户！ " );                      }          ///   <summary>          ///  帮助。          ///   </summary>          ///   <param name="sender"></param>          ///   <param name="e"></param>          private   void  linkLabel1_LinkClicked( object  sender, LinkLabelLinkClickedEventArgs e)         {             help helper  =   new  help();             helper.Show();         }              } } 界面如下： 说明： 不用担心数据库能不能存放下你保存的图片，数据库可以存放2GB大的图片，可以远远满足你的要求。 源码下载： CODE   演示版： DEMO

转载于:https://www.cnblogs.com/tuyile006/archive/2008/01/14/1037932.html