sudo npm install canvas
2、nodejs代码
var Canvas = require('./Common/canvas');var getRandom = function(start,end){ return start+Math.random()*(end-start);};var canvas = new Canvas(50,20);var ctx = canvas.getContext('2d');var s = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';var code = '';for(var i=0;i<4;i++){ code+= s.substr(parseInt(Math.random()*36),1);}var font= 'bold {FONTSIZE}px Impact';//"Bold Italic {FONTSIZE}px arial,sans-serif";//"13px sans-serif";var start = 3;var colors = ["rgb(255,165,0)","rgb(16,78,139)","rgb(0,139,0)","rgb(255,0,0)"];var trans = {c:[-0.108,0.108],b:[-0.05,0.05]};var fontsizes = [11,12,13,14,15,16];for(var i in code){ ctx.font = font.replace('{FONTSIZE}',fontsizes[Math.round(Math.random()*10)%6]); ctx.fillStyle = colors[Math.round(Math.random()*10)%4];//"rgba(0, 0, 200, 0.5)"; ctx.fillText(code[i], start, 15,50); ctx.fillRect(); //con.translate(start,15); //ctx.transform(a,b, c, d, e, f); //参考： //a:水平缩放，default：1 ,取值：0.89,1.32,-0.56等, //b:y轴斜切，default：0 ,取值：-0.89,1.32等, //c:x轴斜切，default：0 ,取值：-0.89,1.32等, //d:垂直缩放，default：1 ,取值：-0.89，0.88,1.32等, //e:平移，default：0 ,取值：-53,52等, //f:纵称，default：0 ,取值：-53,52等, var c = getRandom(trans['c'][0],trans['c'][1]); var b = getRandom(trans['b'][0],trans['b'][1]); //alert(c+','+b); //ctx.transform(1,b, c, 1, 0, 0); start+=11;}//参考下面链接；可发送给客户端console.log('code:'+code);console.log('
");//输出文件到out.png.可方便使用var buf = canvas.toDataURL();var base64Data = buf.replace(/^data:image/w+;base64,/, "");var dataBuffer = new Buffer(base64Data, 'base64');var fs = require("fs");fs.writeFile("out.png", dataBuffer, function(err) { if(err){ console.log("errro！"); }else{ console.log("保存成功！"); } });