为什么在使用点击事件处理程序时执行非匿名函数？ [英] Why are non-anonymous functions being executed when using click event handler?

问题描述

我一直在探索使用自定义函数来处理事件处理程序。在这个简单的例子中，我试图在用户点击一个按钮时弹出一个提示。

I've been exploring the use of custom functions for event handlers. In this stripped down example, I'm trying to get an alert to pop up when the user clicks a button.

但是，当页面加载时，警告框会立即弹出！我究竟做错了什么？ （注释的部分完全相同）

But the alert box pops up immediately as the page loads! What am I doing wrong? ( the commented portion does the exact same thing).

如果我定义bclick（）函数，如

If I define the bclick() function like

function bclick(foo, bar){ ... }

结果也是一样的。

标题中的JS：

<script type="text/javascript">

var bclick = function(foo, bar){alert( foo + "  " + bar + "\n");}

//$(document).ready(function(){
//    $("button").click(bclick("Button","Clicked"));
//    });

$("button").click(bclick("Button","Clicked"));

</script>

正文中的相关HTML：

Relevant HTML in the body:

<button>Click Me!</button> 

推荐答案

您在评估您的功能之前，甚至通过它。

You're evaluating your function before you even pass it.

$("button").click(bclick("Button","Clicked"));

这里，使用这些参数调用 bclick ，而结果正在传递给点击方法。你想像普通变量一样传递它，如下所示：

Here, bclick is called with those arguments, and the result is being passed to the click method. You want to pass it like a normal variable, like this:

$("button").click(bclick);

然而，显而易见的问题是您无法传入自定义参数。

The obvious problem with this, though, is the fact that you can't pass in custom arguments.

您还可以传入一个调用函数的匿名函数：

You could also pass in an anonymous function that calls your function:

$("button").click(function() { bclick("Button", "Clicked"); });

这篇关于为什么在使用点击事件处理程序时执行非匿名函数？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！