对象中的函数指针 [英] Function pointers in objects

问题描述

我有一个javascript函数，它将一个对象作为参数。我希望传递对象的一个​​属性是一个函数指针。但该功能已执行，我不想发生。

I have a javascript function that takes an object as a parameter. I want one of the properties of passed object to be a function pointer. But the function is executed which I don't want to happen.

示例：

var myFuncPtr = function(){alert("Done");};

function myFunc(o){
  // do something with passed object
  // then call the function pointed at in the passed object
}

myFunc( {foo:"bar", onDone: myFuncPtr} );

我确信有专家可以指导我朝着正确的方向前进。我是以错误的方式来做这件事的。如果有快速解决方案，则首选。

I'm sure there's an expert out there who can guide me in the right direction. Am I going about this the wrong way. The quick solution is preferred if there is one.

以下是实际代码：

$(document).ready(function() {
    imageCropper({
        id:"imageBox",
        editWidth:400,
        cropWidth:0,
        maxFileSize:3000000,
        croppedId:"croppedBox",
        onCrop:whenImageCropped
    });
});

function whenImageCropped(o)
{
    alert("done");
}

function imageCropper(options)
{
    divId = options.id;
    croppedDivId = (options.croppedId)?options.croppedId:divId+"_croppedPic";

    $("#"+divId).load("/modules/imageCropper.asp", options, function(){

/* if i remove this bit, then no probs */
        $("#"+divId+"_imgToCrop").Jcrop({
            },function(){jcrop_api = this;}
        );
/* end of - if i remove this bit, then no probs */

    });
}

推荐答案

我希望传递对象的一个​​属性是一个函数指针。但是执行该功能我不想发生。

I want one of the properties of passed object to be a function pointer. But the function is executed which I don't want to happen.

这听起来不是传递对函数的引用，而是正在执行该函数并传递返回值。

That sounds like instead of passing a reference to the function, you are executing the function and passing the return value.

也许在您的原始代码中

myFunc( {foo:"bar", onDone: myFuncPtr()} );

调用 myFuncPtr 并指定返回值到 onDone 。

which calls myFuncPtr and assigns the return value to onDone.

问题中的代码很好，只需在 o.onDone（） > myFunc 。

The code in the question is fine though, just call o.onDone() inside myFunc.

如前所述，没有指针在JavaScript中，它比这简单得多。函数只是数据类型，如字符串，数字，数组等，它们恰好是可调用的。

As already said, there are no pointers in JavaScript, it's much simpler than that. Functions are just data types such as strings, numbers, arrays etc, which happen to be callable.

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