026. asp.net中将图片以二进制方式保存到数据库并以HTTP流方式输出

保存到数据库中

 protected void imgbtnCreate_Click(object sender, ImageClickEventArgs e)
    {
        
        string PerHomeName=tbPerHomeName.Text;//获取空间名
       
        string PerHomeSign=txtPerSign.Text; //获取个性签名
        
        string imgPath = uploadFile.PostedFile.FileName;//获取文件件名
        
        string lastName = imgPath.Substring(imgPath.LastIndexOf(".") + 1);//获取文件上传后缀名
        SqlConnection conn = new SqlConnection( "server=.;database=TYW;uid=sa;pwd=123.456;");
        conn.Open();
        if (uploadFile.PostedFile.FileName != "" && lastName.ToLower() == "jpg" || lastName.ToLower() == "gif")
        {
            if (uploadFile.PostedFile.ContentLength > 40960)
            {
                Response.Write("<script language='javaScript'>alert('你上传的图片超过了40KB！')</script>");
                return;
            }
            int imgLength = uploadFile.PostedFile.ContentLength;//获取上传文件大小
            Byte[] imageData = new Byte[imgLength]; //定义Byte数组
            HttpPostedFile hp = uploadFile.PostedFile;//创建访问客户端上传文件的对象
            Stream imagestream = hp.InputStream;//创建数据流对象
            //将图片数据放到image数据对象实例中，其中0代表数组指针的起始位置，imagelength表示要读取流的长度
            imagestream.Read(imageData, 0, imgLength);
string sqlstr = "insert into card(cardNo,cardBound,email)values('" + 1234 + "','" + 9966770 + "',@ImageData)";
            SqlCommand comm = new SqlCommand(sqlstr, conn);
            comm.Parameters.Add("@ImageData", SqlDbType.Image);
            comm.Parameters["@ImageData"].Value = imageData;
            comm.ExecuteNonQuery();
            conn.Close();
            Response.Write("<Script>alert('个人空间创建成功！')</Script>");
        }
        else
        {
            Response.Write("<script>alert('上传头像不能为空,且格式必须为gif或jpg!');location='javascript:history.go(-1)'</script>");
        }
    }

以HTTP流形式输出到界面:

protected void Page_Load(object sender, EventArgs e)
    {
        string requestID = Request.QueryString["id"];//获取Default.aspx页面传过来的id值
        SqlConnection conn = new SqlConnection("server=.;database=TYW;uid=sa;pwd=123.456;");
        string strsql = "select * from [card] where cardBound=" + 9966770;
        SqlCommand comm = new SqlCommand(strsql, conn);//创建命令对象 
        conn.Open();
        SqlDataReader dr = comm.ExecuteReader();//创建数据阅读器
        if (dr.HasRows)
        {
            while (dr.Read())
            {
                byte[] imageData = (byte[])dr["email"];
                Response.BinaryWrite(imageData);//输出二进制流形式的图片
            }
        }
        dr.Close();
        conn.Close();
    }