C#或ASP.NET的简单绘图
1 public void ProcessRequest (HttpContext context) {
2 context.Response.ContentType = "img/JPEG";
3 using(System.Drawing.Bitmap bm=new System.Drawing.Bitmap(300,100))//规定大小
4 {
5 using(System.Drawing.Graphics g=System.Drawing.Graphics.FromImage(bm))//图像化
6 {
7 g.DrawString("腾讯QQ",new Font("楷体",40),Brushes.Green,new PointF(10,10));
8 g.DrawEllipse(Pens.AliceBlue,new Rectangle(200,10,80,80));
9 bm.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);//保存到网页
10 }
11 }
12
下面这个例子是一个验证码问题
先是example.asph文件
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<div><img src="AddCalation.ashx"onclick="this.src=‘AddCalation.ashx?aaa=‘+new Date()" /></div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
</div>
</form>
</body>
</html>
然后是example.aspx.cs文件
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class TestCode : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
string code = Session["test"].ToString();
if(code==TextBox1.Text)
{
Response.Write("匹配正确");
}
else
{
Response.Write("匹配错误");
}
}
}
再是验证码图片创造文件example.ashx
1 <%@ WebHandler Language="C#" Class="AddCalation" %>
2
3 using System;
4 using System.Web;
5 using System.Drawing;
6 public class AddCalation : IHttpHandler,System.Web.SessionState.IRequiresSessionState{
7
8 public void ProcessRequest (HttpContext context) {
9 context.Response.ContentType = "img/JPEG";
10 using(System.Drawing.Bitmap bm=new System.Drawing.Bitmap(150,60))
11 {
12 using(System.Drawing.Graphics g=System.Drawing.Graphics.FromImage(bm))
13 {
14 Random rand = new Random();
15 int code = rand.Next();
16 string testcode=code.ToString().Substring(0,4);
17 HttpContext.Current.Session["test"] = testcode;
18 g.DrawString(testcode,new Font("楷体",40),Brushes.Green,new PointF(10,5));
19
20 bm.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
21 }
22 }
23
24
25 }
26
27 public bool IsReusable {
28 get {
29 return false;
30 }
31 }
32
33 }
执行效果如下图
时间： 2024-10-26 03:06:07