图片保存到数据库的方法：

public void imgToDB(string sql)
{ //参数sql中要求保存的imge变量名称为@images
//调用方法如：imgToDB("update UserPhoto set Photo=@images where UserNo='" + temp + "'");
FileStream fs = File.OpenRead(t_photo.Text);
byte[] imageb = new byte[fs.Length];
fs.Read(imageb,imageb.Length);
fs.Close();
sqlCommand com3 = new sqlCommand (sql,con);
com3.Parameters.Add("@images",sqlDbType.Image).Value = imageb;
if (com3.Connection.State == ConnectionState.Closed)
com3.Connection.Open();
try
{
com3.ExecuteNonQuery();
}
catch
{ }
finally
{ com3.Connection.Close(); }
}

数据库中读出图片并显示在pictureBox中：

方法一：
private void ShowImage(string sql)
{
//调用方法如：ShowImage("select Photo from UserPhoto where UserNo='" +userno +"'");
sqlCommand cmd = new sqlCommand(sql,conn);
conn.Open();
byte[] b= (byte[])cmd.ExecuteScalar();
if (b.Length 〉 0)
{
MemoryStream stream = new MemoryStream(b,true);
stream.Write(b,b.Length);
pictureBox1.Image = new Bitmap(stream);
stream.Close();
}
conn.Close();
}

方法二：当在dg中选中某行时： private void dg_MouseUp(object sender,MouseEventArgs e) { //整行选择 if (e.Button == System.Windows.Forms.MouseButtons.Left) {//用户编号，姓名，性别，身份证号，籍贯，学院，系所，校区，部门，电话，照片//显示相片 object imgobj=dg[10,dg.CurrentRow.Index].Value; if (imgobj != null && !Convert.IsDBNull(imgobj)) { byte[] imgb = (byte[])imgobj; MemoryStream memStream = new MemoryStream(imgb); try { Bitmap myimge = new Bitmap(memStream); this.pictureBox1.Image = myimge; } catch { DB.msgBox("从数据库读取相片失败！"); } } else pictureBox1.Image = null; } }