图片保存到数据库和从数据库读取图片并显示（C＃）

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, 0, 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, 0, 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;
}
}