验证码的图片背景颜色
我想把验证码的背景颜色改为蓝色以和页面统一,但不知怎么改。大家帮忙。谢谢!
private void Page_Load(object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
// RndNum是一个自定义函数
string VNum = RndNum(5);
Session["VNum"] = VNum;
ValidateCode(VNum);
}
private void ValidateCode(string VNum)
{
//生成验证code
System.Drawing.Bitmap img;
System.Drawing.Graphics g;
System.IO.MemoryStream ms;
int gheight = Convert.ToInt32(VNum.Length*11.5);
//gheight为图片宽度,根据字符长度自动更改图片宽度
img = new Bitmap(gheight,20);
g = Graphics.FromImage(img);
//在矩形内绘制字串(字串,字体,画笔颜色,左上x.左上y)
g.DrawString(VNum,new Font("Arial",10),new SolidBrush(System.Drawing.Color.Red),3,3);
ms = new MemoryStream();
img.Save(ms,ImageFormat.Png);
Response.ClearContent(); //需要输出图象信息 要修改HTTP头
Response.ContentType = "image/gif";
Response.BinaryWrite(ms.ToArray());
g.Dispose();
img.Dispose();
Response.End();
}
// '函数名称:RndNum
// '函数参数:VcodeNum--设定返回随机字符串的位数
// '函数功能:产生数字和字符混合的随机字符串
private string RndNum(int VcodeNum)
{
string Vchar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z" ;
string[] VcArray = Vchar.Split(",".ToCharArray()); //将字符串生成数组
string VNum = "";
int i;
System.Random ro = new Random();
for(i=1;i<VcodeNum;i++)
{
double decA = ro.NextDouble();
VNum = VNum + VcArray[Convert.ToInt32(35*decA)];
}
// For i=1 to VcodeNum
// Randomize
// VNum=VNum & VcArray(Int(35*Rnd)) '数组一般从0开始读取,所以这里为35*Rnd
// Next
return VNum;
}