C# 图片保存到数据库和从数据库读取图片并显示

C# 图片保存到数据库和从数据库读取图片并显示

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;

}

}