话不多说，请看代码：
<!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 表示画布节点
//staX 表示开始x坐标
//staY 表示开始y坐标
//len表示终点坐标，
//timing表示运行的间隔时间，
//num表示坐标增长的大小
/https://img.qb5200.com/download-x/direc表示判断绘制线条的方向，false表示X轴，ture表示Y轴
//lw表示线宽的大小
//color 表示绘制线条颜色
Anim.prototype.draw = function() { //绘制直线的线条
var opt = this.opt; //设置对象的属性
var adx = opt.staX;
var ady = opt.staY;
var that = {
x: opt.staX,
y: opt.staY
};
var Time = setInterval(function() {
opt.direc //判断绘制方向
?
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) { //停止循环
clearInterval(Time);
}
opt.Node.beginPath(); // 开始绘制线条
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) {//绘制文字
cvs.beginPath();
cvs.fillStyle = "rgba(255,255,255,"+opc+")";
cvs.font = "200px arial";
cvs.fillText("L", 100, 200);
};
var line1 = new Anim({ //实例
Node: cvs,
color: "#fff",
staX: 114,
staY: 58,
len: 134,
timing: 50,
num: 1,
direc: false,
lw: 2
});
line1.draw(); //执行绘制
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();//绘制文字实例
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内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，同时也希望多多支持！
