話不多說，請看代碼：
<!DOCTYPE html><html> <head> <meta charset="UTF-8"> <title>first line</title> <style type="text/css"> body{ background: #456E89; } .canvas { height: 300px; width: 300px; margin: 0 auto; font-family: arial; } </style> </head> <body> <div class="canvas"> <canvas id="cvs" width="300" height="300"></canvas> </div> <script type="text/javascript"> var cvs = document.getElementById("cvs").getContext("2d"); function Anim(opt) { //初始化值 this.opt = opt; } //node 表示畫布節點 //staX 表示開始x坐標 //staY 表示開始y坐標 //len表示終點坐標， //timing表示運行的間隔時間， //num表示坐標增長的大小 //direc表示判斷繪制線條的方向，false表示X軸，ture表示Y軸 //lw表示線寬的大小 //color 表示繪制線條顏色 Anim.prototype.draw = function() { //繪制直線的線條 var opt = this.opt; //設置對象的屬性 var adx = opt.staX; var ady = opt.staY; var that = { x: opt.staX, y: opt.staY }; var Time = setInterval(function() { opt.direc //判斷繪制方向 ? opt.len > ady ? ady += opt.num : ady -= opt.num : opt.len > adx ? adx += opt.num : adx -= opt.num; if(adx == opt.len || ady == opt.len) { //停止循環 clearInterval(Time); } opt.Node.beginPath(); // 開始繪制線條 opt.Node.moveTo(that.x, that.y); opt.Node.lineTo(adx, ady); opt.Node.lineWidth = opt.lw || 1; opt.Node.strokeStyle = opt.color; opt.Node.stroke(); }, opt.timing); }; Anim.prototype.txt = function(opc) {//繪制文字 cvs.beginPath(); cvs.fillStyle = "rgba(255,255,255,"+opc+")"; cvs.font = "200px arial"; cvs.fillText("L", 100, 200); }; var line1 = new Anim({ //實例 Node: cvs, color: "#fff", staX: 114, staY: 58, len: 134, timing: 50, num: 1, direc: false, lw: 2 }); line1.draw(); //執行繪制 var line2 = new Anim({ Node: cvs, color: "#fff", staX: 115, staY: 58, len: 200, timing: 20, num: 1, direc: true, lw: 2 }); line2.draw(); var line3 = new Anim({ Node: cvs, color: "#fff", staX: 133, staY: 184, len: 58, timing: 20, num: 1, direc: true, lw: 2 }); line3.draw(); var line4 = new Anim({ Node: cvs, color: "#fff", staX: 132, staY: 184, len: 203, timing: 35, num: 1, direc: false, lw: 2 }); line4.draw(); var line5 = new Anim({ Node: cvs, color: "#fff", staX: 203, staY: 199, len: 115, timing: 35, num: 1, direc: false, lw: 2 }); line5.draw(); var line6 = new Anim({ Node: cvs, color: "#fff", staX: 203, staY: 199, len: 184, timing: 50, num: 1, direc: true, lw: 2 }); line6.draw(); var test = new Anim();//繪制文字實例 setTimeout(function () { var num = 0; var times = setInterval(function () { num++; var t = num/100; if(t === 1){ clearInterval(times); } test.txt(t); },50) },3000) </script> </body></html>以上就是本文的全部內容，希望本文的內容對大家的學習或者工作能帶來一定的幫助，同時也希望多多支持VeVb武林網！
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