我試圖理解一個代碼,一個帆布例如:帆布,觸發鼠標事件
爲什麼在事件處理程序代碼中的第三個參數「假」?它代表什麼?
這裏的完整代碼
function init() {
// ...
// Attach the mousemove event handler.
canvas.addEventListener('mousemove', ev_mousemove, false);
}
// The mousemove event handler.
var started = false;
function ev_mousemove (ev) {
var x, y;
// Get the mouse position relative to the canvas element.
if (ev.layerX || ev.layerX == 0) { // Firefox
x = ev.layerX;
y = ev.layerY;
}
非常感謝你,有很大的幫助! – user1477955 2013-03-22 14:48:39