image.aspx.cs

投票系统VS2005+SQL2000 三层结构

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.SessionState;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Drawing;
using System.IO;


public partial class Image : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            CreateImage();
        }
    }


    /// <summary>
    /// 输出图片长度
    /// </summary>
    public int Length
    {
        get
        {
            if (Request.QueryString["per"] == null)
                return 1;

            int iPer = Convert.ToInt32(Request.QueryString["per"]);
            if (iPer > 0)
                return (150 * iPer / 100);

            return 1;
        }
    }


    /// <summary>
    /// 输出图片
    /// </summary>
    private void CreateImage()
    {
        //根据字符串的长度确定输出图片的长度
        System.Drawing.Bitmap image = new System.Drawing.Bitmap(Length, 15);

        //创建Graphics对象
        Graphics g = Graphics.FromImage(image);

        try
        {
            //画图片的边框线
            g.DrawRectangle(
                new Pen(Color.Pink),
                0,
                0,
                image.Width - 1,
                image.Height - 1);

            //创建内存流用于输出图片
            using(MemoryStream ms = new MemoryStream())
            {
                //图片格式指定为png
                image.Save(ms, ImageFormat.Png);

                //清除缓冲区流中的所有输出
                Response.ClearContent();

                //输出流的HTTP MIME类型设置为"image/Png"
                Response.ContentType = "image/Png";

                //输出图片的二进制流
                Response.BinaryWrite(ms.ToArray());
            }
        }
        finally
        {
            //释放Bitmap对象和Graphics对象
            g.Dispose();
            image.Dispose();
        }
    }
}