jQuery新手：如何将参数传递给事件处理函数？

I'm looking at the example for the "click" event in the jQuery documentation here. I can refactor the two anonymous functions as follows and it still works:

我在这里查看jQuery文档中“click”事件的示例。我可以按如下方式重构两个匿名函数,它仍然有效:

$(document).ready(function(){
    $("p").hover(hilite, remove_hilite);
  });

  function hilite()
  {
    $(this).addClass("hilite");
  }

  function remove_hilite()
  {
    $(this).removeClass("hilite");
  }

However, what if I want to pass an argument to hilite? My first guess was that I should use an anonymous function like this. However, this does not seem to work, even when I'm using it without arguments:

但是,如果我想将一个参数传递给hilite怎么办?我的第一个猜测是我应该使用这样的匿名函数。但是,即使我在没有参数的情况下使用它,这似乎也不起作用:

$("p").hover(
    function()
    {
        hilite();
    }
    ,
    function()
    {
        remove_hilite();
    }
);

I also tried refactoring as follows, but this did not work either:

我也尝试重构如下,但这也不起作用:

$(document).ready(function(){
    $("p").hover(hilite2, remove_hilite);
  });

  function hilite2(){
     return hilite();
  }

What is the proper way to do this? I feel like I have a big conceptual misunderstanding. In particular, I am unclear about how in my first refactoring, the this object is passed to the hilite function.

这样做的正确方法是什么?我觉得我有一个很大的概念误解。特别是,我不清楚在我的第一次重构中,这个对象是如何传递给hilite函数的。

3 个解决方案

#1

You can encapsulate your hover function call into another function that accepts the 'className' parameter:

您可以将悬停函数调用封装到另一个接受'className'参数的函数中:

$.fn.hoverClass = function(className){
    return this.hover(function(){
        $(this).addClass(className);
    }, function(){
        $(this).removeClass(className);
    });
}

Then you can use it simply by this:

然后你可以简单地使用它:

$('p').hoverClass('hilite');

#2

I think that what you want is a partial function application.

我认为你想要的是一个部分功能应用程序。

function partial(func /*, 0..n args */) {
  var args = Array.prototype.slice.call(arguments, 1);
  return function() {
    var allArguments = args.concat(Array.prototype.slice.call(arguments));
    return func.apply(this, allArguments);
  };
}

With the above function, you can now do the following:

使用上述功能,您现在可以执行以下操作:

$(document).ready(function(){
    var f = partial(hilite, "arg1", "arg2" /*etc...*/);
    $("p").hover(f, remove_hilite);
  });

Reference: How can I pre-set arguments in JavaScript function call? (Partial Function Application)

参考:如何在JavaScript函数调用中预先设置参数? (部分功能应用)

#3

Why can't you simply call the $(this).addClass() method within the anonymous functions?

为什么不能简单地在匿名函数中调用$(this).addClass()方法?

$("p").hover(
  function () {
    $(this).addClass("hilight");
  },
  function () {
    $(this).removeClass("hilight");
  }
);

#1