| 发表于:2007-03-22 23:51:414楼 得分:0 |
//--下面是一个生成 验证码的程序代码 楼主看看应该就能明白 输出类型改成.png即可 using system; using system.collections; using system.componentmodel; using system.data; using system.drawing; using system.drawing.drawing2d; using system.drawing.imaging; using system.io; using system.web; using system.web.sessionstate; using system.web.ui; using system.web.ui.webcontrols; using system.web.ui.htmlcontrols; public partial class validate : system.web.ui.page { private const int rndlength = 4; protected void page_load(object sender, eventargs e) { // 在此处放置用户代码以初始化页面 string vnum; vnum = getbyrndnum(); session[ "validatecode "] = vnum; response.clearcontent(); //需要输出图象信息 要修改http头 //response.bufferoutput = false; response.contenttype = "image/jpeg "; response.binarywrite(getbyvalidatecode(vnum).toarray()); //response.close(); } private memorystream getbyvalidatecode(string vnum)//返回内存流 { bitmap img = null; graphics g = null; memorystream ms = null; random random = new random(); int gheight = vnum.length * 12; img = new bitmap(gheight, 20); g = graphics.fromimage(img); font f = new font( "arial ", 12, fontstyle.bold); g.clear(getbyrandcolor(180, 200));//设定背景色 pen blackpen = new pen(color.antiquewhite, 1); //pen blackpen = new pen(color.black ,1); for (int i = 0; i < 32; i++)// 随机产生干扰线,使图象中的认证码不易被其它程序探测到 { int x = random.next(gheight); int y = random.next(20); int xl = random.next(6); int yl = random.next(12); g.drawline(blackpen, x, y, x + xl, y + yl); } solidbrush s = new solidbrush(color.saddlebrown); g.drawstring(vnum, f, s, 3, 3); ms = new memorystream(); img.save(ms, system.drawing.imaging.imageformat.jpeg);//jpeg改png即可 g.dispose(); img.dispose(); return ms; } //-----------------给定范围获得随机颜色------------ color getbyrandcolor(int fc, int bc) { random random = new random(); if (fc > 255) fc = 255; if (bc > 255) bc = 255; //if(ac> 255) ac=255; int r = fc + random.next(bc - fc); int g = fc + random.next(bc - fc); int b = fc + random.next(bc - bc); color rs = color.fromargb(r, g, b); return rs; } //-----------------------取随机产生的认证码(n位数字) public string getbyrndnum() { 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( ', '); string vnum = " "; //采用一个简单的算法以保证生成随机数的不同 random rand = new random(); int[] rndarr = new int[rndlength]; for (int i = 1; i < rndlength + 1; i++) { if(i> 1) { do { rndarr[i-1] = rand.next(10);//rand.next(35) ; bool goon = false; for(int ix=0; ix <i-1; ix++) { if (rndarr[ix] == rndarr[i-1]) { goon = true; break; } } if (!goon) break; } while (1 == 1); } else rndarr[i-1] = rand.next(10); vnum += rndarr[i-1]; } return vnum; } } | | |
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