AJAX不太懂,帮忙解释下
//设置显示位置
function setOffsets() {
completeTable.style.width = inputField.offsetWidth; + "px";
var left = calculateOffset(inputField, "offsetLeft");
// var left = inputField(offsetLeft);
var top = calculateOffset(inputField, "offsetTop") + inputField.offsetHeight;
alert(left);
alert(top);
completeDiv.style.border = "black 1px solid";
completeDiv.style.left = left + "px";
completeDiv.style.top = top + "px";
}
//计算显示位置
function calculateOffset(field, attr) {
var offset = 0;
while(field) {
offset += field[attr];
field = field.offsetParent;
}
return offset;
}
计算显示位置,为什么要写个函数来计算了,
while(field)是什么意思,为什么要用循环,他代表什么
还要 offset += field[attr];
field = field.offsetParent;
都是什么意思,今天刚看这代码,有点摸不着头绪
请大家赐教