我有这段代码，它显示了用户在屏幕上拖动手指时触摸的坐标。问题是，如果我触摸屏幕的时间过长，它会选择整个 Canvas 并显示“复制”气泡，这是默认行为。我该如何摆脱它？
<html>
<head>
<script type="application/javascript">
function drawCross(color,x,y){
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
ctx.beginPath();
ctx.strokeStyle=color;
ctx.lineWidth=4;
ctx.moveTo(x,0);
ctx.lineTo(x,480);
ctx.moveTo(0,y);
ctx.lineTo(320,y);
ctx.stroke();
}
document.addEventListener('touchmove', function(event) {
event.preventDefault();
var touch = event.touches[0];
drawCross('#ffffff', document.getElementById('oldX').value,
document.getElementById('oldY').value);
drawCross('#cc0000',touch.pageX,touch.pageY);
document.getElementById('oldX').value=touch.pageX;
document.getElementById('oldY').value=touch.pageY;
}, false);
document.addEventListener('touchend', function(event) {
event.preventDefault();
drawCross('#ffffff', document.getElementById('oldX').value,
document.getElementById('oldY').value);
document.getElementById('oldX').value=0;
document.getElementById('oldY').value=0;
}, false);
</script>
</head>
<body>
<input id="oldX" type="hidden" value="0">
<input id="oldY" type="hidden" value="0">
<div>
<canvas id="canvas" width="320" height="480"></canvas>
</div>
</body>
</html>
最佳答案
刚刚为 touchstart 添加了一个监听器，它起作用了:)
// listener for the touch
document.addEventListener('touchstart', function(event) {
event.preventDefault();
}, false);
关于iphone - HTML5 iPhone preventDefault() 不会从 "copy"停止以在触摸时出现，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/3597181/