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我嘗試繪製我的鼠標在畫布上的路徑，但我不知道什麼是錯的，但它不畫任何東西。它適用於context.fillRect()，但不是惠普ImageData。這是我的代碼：onmouse畫布HTML5
<!DOCTYPE HTML>
<html>
<head>
</head>
<body>
<canvas id="myCanvas" width="600" height="600" style=" border-style: solid;"></canvas>
<script>
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
var canvasWidth = canvas.width;
var canvasHeight = canvas.height;
var canvasData = context.getImageData(0, 0, canvasWidth, canvasHeight);
function drawPixel(x, y) {
var index = (x + y * canvasWidth) * 4;
canvasData.data[index] = 0; //Red
canvasData.data[index + 1] = 255; //Green
canvasData.data[index + 2] = 0; //Blue
canvasData.data[index + 3] = 1; //Alpha
}
function updateCanvas() {
context.putImageData(canvasData, 0, 0);
}
function getMousePos(canvas, evt) {
var rect = canvas.getBoundingClientRect();
return {
x: Math.round((evt.clientX-rect.left)/(rect.right-rect.left)*canvas.width),
y: Math.round((evt.clientY-rect.top)/(rect.bottom-rect.top)*canvas.height)
};
}
canvas.addEventListener('mousemove', function(evt) {
var mousePos = getMousePos(canvas, evt);
drawPixel(mousePos.x, mousePos.y);
updateCanvas();
}, false);
</script>
</body>
</html>