O atributo onclick = “function ()” não está funcionando conforme o esperado?
Tentei resolver o problema e não consigo encontrar a solução. Algumas horas depois, descobri que o problema está na tag button ou no atributo onclick (me corrija se estiver errado).
Meu objetivo é fazer o ponto branco se mover através de botões
<!DOCTYPE html>
<html>
<head>
<title></title>
<script type="text/javascript">
window.onload = function()
{
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
canvas.width = 345;
canvas.height = 410;
canvas.style.border = "1px solid white";
var left = document.getElementById("left");
left.onclick = "playerLeft()";
var x = Math.round(canvas.width/2);
var y = Math.round(canvas.width/2);
var rectWidth = 5, rectHeight = 5;
var fps = 30, frames = 1000/fps;
var colour = "white";
var trailColour = "blue";
ctx.fillStyle = colour;
ctx.fillRect(x,y,rectWidth,rectHeight);
function playerLeft() {
ctx.fillStyle = trailColour;
ctx.fillRect(x,y,rectWidth,rectHeight);
x -= 6;
ctx.fillStyle = colour;;
ctx.fillRect(x,y,rectWidth,rectHeight);
}
function playerRight() {
ctx.fillStyle = trailColour;
ctx.fillRect(x,y,rectWidth,rectHeight);
x += 6;
ctx.fillStyle = colour;
ctx.fillRect(x,y,rectWidth,rectHeight);
}
function playerUp() {
ctx.fillStyle = trailColour;
ctx.fillRect(x,y,rectWidth,rectHeight);
y -= 6;
ctx.fillStyle = colour;
ctx.fillRect(x,y,rectWidth,rectHeight);
}
function playerDown() {
ctx.fillStyle = trailColour;
ctx.fillRect(x,y,rectWidth,rectHeight);
y += 6;
ctx.fillStyle = colour;
ctx.fillRect(x,y,rectWidth,rectHeight);
}
}
</script>
</head>
<body style="background-color: black">
<canvas id="canvas"></canvas>
<div style="text-align: center; padding: 5px">
<button id="left">Left</button>
<button id="up">Up</button>
<button id="down">Down</button>
<button id="right">Right</button>
</div>
</body>
</html>