函数未被调用，使用jquery .delegate

Question

I want to use jquery delegate to call a function, and this works fine:

$("body").delegate("div", "mouseover", function(){
alert("it works");
});

But I also want to be able to use the same function elsewhere. So rather than writing the same function out several times, I can just declare it separately, and call it by name, right?

But written this way, I never see the alert.

function alertMe(){
alert("it works");
};

$("body").delegate("div", "mouseover", alertMe());

Answer 1

Drop the parenthisis while defining delegate. just give the function-name

$("body").delegate("div", "mouseover", alertMe);

Answer 2

jQuery .delegate has been superseded by the .on method. I would recommend you change your code to use it.

function alertMe(){
    alert("it works");
}

$("body").on("mouseover", "div", alertMe);
//$("body").delegate("div", "mouseover", alertMe) -- old method
//Note the change in postion of selector and event

Answer 3

it's better to do this:

$("body").delegate("div", "mouseover", function(){
   alertMe();
   //plug more code down here
});

it has advantages, mainly:

• if you want other stuff done after the event, just add it in
• you can call more functions in this form (rather than that single alertMe() )

Answer 4

Creating the common event handler is easy

function alertMe(event){
    //you also need to include the event object, for various actions like stopPropagation()
    alert("it works");
};

$("body").delegate("div", "mouseover", alertMe);