Javascript 在HTML5中水平绘制多个圆
如何绘制多个与此代码水平对齐的圆?我试过打圈,但没用Javascript 在HTML5中水平绘制多个圆,javascript,html,Javascript,Html,如何绘制多个与此代码水平对齐的圆?我试过打圈,但没用 <!doctype html> <html> <head> <title> Draw circle </title> <body> <canvas id="myCanvas" width="500" height="300" style="border:solid 2px white;"> <
<!doctype html>
<html>
<head>
<title> Draw circle </title>
<body>
<canvas id="myCanvas" width="500" height="300" style="border:solid 2px white;">
</canvas>
<script>
var canvas = document.getElementById("myCanvas");
var context = canvas.getContext("2d");
function draw_circle (circleX, circleY, radius, fill) {
context.fillStyle = "black";
context.fillRect(0, 0, 500, 300);
context.strokeStyle = "red";
context.strokeRect(5, 5, 490, 290);
context.fillStyle = fill;
context.arc(circleX, circleY, radius, 0, Math.PI*2);
context.fill();
}
draw_circle(100, 100, 30 , "cyan");
</script>
</body>
</html>
画圈
var canvas=document.getElementById(“myCanvas”);
var context=canvas.getContext(“2d”);
函数绘制圆(圆、圆、半径、填充){
context.fillStyle=“黑色”;
fillRect(0,0500300);
context.strokeStyle=“红色”;
strokeRect(5,5490290);
context.fillStyle=fill;
弧(圆,圆,半径,0,数学π*2);
context.fill();
}
画一个圆圈(100,100,30,“青色”);
var canvas=document.getElementById(“myCanvas”);
var context=canvas.getContext(“2d”);
函数drawWindow(){
context.fillStyle=“黑色”;
fillRect(0,0500300);
context.strokeStyle=“红色”;
strokeRect(5,5490290);
}
函数绘制圆(圆、圆、半径、填充){
context.fillStyle=fill;
弧(圆,圆,半径,0,数学π*2);
context.fill();
}
拉窗();
对于(var i=0;i您的draw_circle
函数每次调用时都会用黑色填充画布。您应该只运行该代码一次。明白了,感谢您的更正:)感谢您的回答,并发布用户3087839,它可以工作:)
<canvas id="myCanvas" width="500" height="300" style="border:solid 2px white;">
</canvas>
<script>
var canvas = document.getElementById("myCanvas");
var context = canvas.getContext("2d");
function drawWindow(){
context.fillStyle = "black";
context.fillRect(0, 0, 500, 300);
context.strokeStyle = "red";
context.strokeRect(5, 5, 490, 290);
}
function draw_circle (circleX, circleY, radius, fill) {
context.fillStyle = fill;
context.arc(circleX, circleY, radius, 0, Math.PI*2);
context.fill();
}
drawWindow();
for(var i = 0; i <= 3 ; i++){
draw_circle((i*60)+100,100, 30 , "cyan");
}
</script>