.net剪切图片源码

从数据库中提取图片,存为bmp

C# code
SqlConnection conn = new SqlConnection("server=.;uid=sa;pwd=;database=库");
            conn.Open();
            string strSql = "select 字段 from 表 ";
            SqlCommand cmd = new SqlCommand(strSql, conn);
            SqlDataReader sdr = cmd.ExecuteReader();
            sdr.Read();
            MemoryStream ms = new MemoryStream((byte[])sdr[0]);
            Image image = Image.FromStream(ms);
            sdr.Close();
            conn.Close();
            Bitmap bmp=new Bitmap(image);
截取图片,好像只需要左上角的点和长宽即可. 代码你可以自己换算一下
C# code

 Rectangle roi = new Rectangle(left, top, Width, Height);

using (Bitmap bmp = new Bitmap(roi.Width, roi.Height))
using (Graphics g = Graphics.FromImage(bmp))
{
                g.CopyFromScreen(this.PointToScreen(roi.Location), Point.Empty, roi.Size);
 }

存回去

C# code 
           MemoryStream   ms   =   new   MemoryStream();  
           bmp.Save(   ms,   ImageFormat.Jpeg   );  
           ms.Flush();  
           byte[]   picbyte=   ms.GetBuffer();  
           ms.Close();  
            SqlConnection conn = new SqlConnection("server=.;uid=sa;pwd=;database=库");
            conn.Open();
            string sqlstring = "insert into 表(字段) values(@img)";
            SqlCommand cmd = new SqlCommand(sqlstring, conn);
            cmd.Parameters.Add("@img", SqlDbType.Image, picbyte.Length).Value = picbyte;

            cmd.ExecuteNonQuery();            conn.Close();