数据库读取图片展示

将bitmap保存到页面的输出流中。在其它页面的img的src就可以使用这个流。

img.aspx：

protected void Page_Load(object sender, EventArgs e)
        {
            Bitmap img = null;
            string connStr = ConfigurationManager.ConnectionStrings["dbConn"].ToString();
            using (SqlConnection conn = new SqlConnection(connStr))
            {
                conn.Open();
                string sql = "SELECT IMG FROM MOVIE WHERE IMG IS NOT NULL";
                SqlCommand cmd = new SqlCommand(sql, conn);
                object obj = cmd.ExecuteScalar();
                conn.Close();
                if (obj != null)
                {
                    byte[] buffer = (byte[])obj;
                    MemoryStream mStream = new MemoryStream(buffer);
                    img = new Bitmap(mStream);
                }
                else
                {
                    img = new Bitmap(Server.MapPath("img/android.jpg"));
                }
            }
            img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
            Response.End();
        }

<img alt="" src="img.aspx" />

上传图片到数据库（img字段为image格式）：

        protected void btnUpload_Click(object sender, EventArgs e)
        {
            int fileLeng = FileUpload1.PostedFile.ContentLength;
            byte[] buffer = new byte[fileLeng];
            Stream stream = FileUpload1.FileContent;
            stream.Read(buffer, 0, fileLeng);

            string connStr = ConfigurationManager.ConnectionStrings["dbConn"].ToString();
            using (SqlConnection conn = new SqlConnection(connStr))
            {
                conn.Open();
                string sql = "UPDATE Movie SET IMG=@img WHERE IMG IS NULL";
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.Parameters.Add("@img", SqlDbType.Image);
                cmd.Parameters["@img"].Value = buffer;
                cmd.ExecuteNonQuery();
            }
        }