使用onreadystatechange的JQuery

Question

有人可以解释为什么我的所有JQuery尝试使用此事件都无法正常工作吗？

function readyStateChanged() {
    alert(document.readyState);
}

document.onreadystatechange = readyStateChanged;            // works 
$(document).on('onreadystatechange', readyStateChanged);    // doesn't work
$(document).bind('onreadystatechange', readyStateChanged);  // doesn't work
$(document).onreadystatechange(readyStateChanged);          // doesn't work

Answer 1

function readyStateChanged() {
    alert(document.readyState);
}

$(document).on('readystatechange', readyStateChanged);