asp.net从数据库中读取图片

    /**//// <summary>
    /// 经过处理获取所略图
    /// </summary>
    /// <param name="ms"></param>
    /// <param name="height"></param>
    /// <returns></returns>
    private byte[] LessonPicAutoWidth(MemoryStream ms, int height)
    {
        byte[] ChagedByte;
        System.Drawing.Image OriginalImage = System.Drawing.Image.FromStream(ms, true);
        System.Drawing.Bitmap OriginalPic, NewPic;
        OriginalPic = new System.Drawing.Bitmap(OriginalImage);

        int Width = height * OriginalPic.Width / OriginalPic.Height;

        if (Width > 280)
        {
            Width = 280;
        }

        NewPic = new Bitmap(OriginalPic, Width, height);
        MemoryStream Newms = new MemoryStream();
        NewPic.Save(Newms, System.Drawing.Imaging.ImageFormat.Jpeg);
        ChagedByte = Newms.GetBuffer();
        OriginalPic.Dispose();
        NewPic.Dispose();
        Newms.Close();

        return ChagedByte;
    }

    /**//// <summary>
    /// 显示图片
    /// </summary>
    /// <param name="EmployeeID"></param>
    public void GetPhoto(string EmployeeID, int height)
    {
        Bitmap bmp;
        byte[] PhotoByte;
        string cnstr;
        string sql;
        cnstr = "Data Source=localhost;Database=Northwind;uid=sa;pwd=123";
        sql = "Select Photo From Employees Where EmplyeeID=" + EmployeeID;

        using (SqlConnection cn = new SqlConnection(cnstr))
        {
            using (SqlCommand cmd = cn.CreateCommand())
            {
                cn.Open();
                cmd.CommandText = sql;
                using (SqlDataReader reader = cmd.ExecuteReader(CommandBehavior.SequentialAccess))
                {
                    reader.Read();
                    PhotoByte = (byte[])reader.GetValue(0);
                }
            }
        }
        if (PhotoByte == null || PhotoByte.Length == 0) return;

            MemoryStream tempStream = new MemoryStream(PhotoByte);
        PhotoByte = LessonPicAutoWidth(tempStream, height);
        bmp = new Bitmap(tempStream);

        Response.ContentType = "image/gif";
        bmp.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);
        Response.End();
    }

转载于:https://www.cnblogs.com/yuzhixue/archive/2006/10/18/532373.html