Javascript 移动并清除画布标记中的行

Javascript 移动并清除画布标记中的行,javascript,jquery,css,html5-canvas,html5-audio,Javascript,Jquery,Css,Html5 Canvas,Html5 Audio,var-isInc=true; var canvas=document.getElementById('myCanvas'); var context=canvas.getContext('2d'); var计数器=0; setInterval(函数(){ context.beginPath(); 上下文。移动到(10+计数器,10); lineTo(40,40); context.lineWidth=1; closePath(); stroke(); 控制台日志(计数器); 如果(计数器==5

var-isInc=true;
var canvas=document.getElementById('myCanvas');
var context=canvas.getContext('2d');
var计数器=0;
setInterval(函数(){
context.beginPath();
上下文。移动到(10+计数器,10);
lineTo(40,40);
context.lineWidth=1;
closePath();
stroke();
控制台日志(计数器);
如果(计数器==50)isInc=false;
如果(计数器==0)isInc=true,则为else;
如果(isInc)计数器=计数器+10;
else计数器=计数器-10;
}, 1000);
var-isInc=true;
var canvas=document.getElementById('myCanvas');
var context=canvas.getContext('2d');
var计数器=0;
setInterval(函数(){
clearRect(0,0578200);
context.beginPath();
上下文。移动到(10+计数器,10);
lineTo(40,40);
context.lineWidth=1;
closePath();
stroke();
控制台日志(计数器);
如果(计数器==50){
isInc=假;
}else if(计数器==0){
isInc=真;
}
计数器=isInc?计数器+10:计数器-10;
}, 1000);