说到底, pageY, clientY, screenY的计算,就是要找到参考点, 它们的值就是: 鼠标点击的点----------- 和参考点指点----------的直角坐标系的距离 stackoverflow上面有个回答,讲解的非常清晰. offsetX and offsetY are relative to the parent container, whereas pageX and pageY are relative to the document // rect is a DOM…