Titanium Javascript:“那个".不起作用 [英] Titanium Javascript: "that." does not work

问题描述

这个和那个都不行.有人知道这是怎么回事吗??

Neither this nor that works. Does anyone know what is going on??

qwerty 简称为qwerty();"在其他代码段中时.它应该是独立的.

qwerty is simply called as "qwerty();" when in other pieces of code. It is supposed to be indepedent.

我意识到出了什么问题.问题在于我...

I realize what is wrong. The problem lies with the i...

function qwerty () {
..... for loop that changes i ......

var that = this;
this.chara[i] = createlabel.....

this.chara[i].addEventListener('click', function(e) {
    var j = e.source.id;
    alert("hello word");
    alert(this.chara[j].width); // I get the error here
});

this.chara[i].addEventListener('doubleclick', function(e) {
    alert("hello word");
    alert(that.chara[i].width); // I get the error here too.
});
}

推荐答案

任何与 this 相关的 JS 问题很可能是由于函数使用 this 被调用.在您的 that 变量中存储对 this 的引用应该可以让您从嵌套函数中引用它，这正是您已经在做的方式 - 假设 qwerty() 的调用方式是首先将 this 设置为正确的对象.(我个人喜欢称这样的变量为 self，因为它更准确地反映了变量在做什么.)

Any JS problem relating to this is likely due to the way the function using this is called. Storing a reference to this in your that variable should let you reference it from within your nested functions, exactly the way you are doing it already - assuming that qwerty() is called in a way that sets this to the correct object in the first place. (Personally I like to call such a variable self since it more accurately reflects what the variable is doing.)

但是，在您的函数中，您说在这一行出现错误:

However, in your function you say you get the error on this line:

that.chara[i].width

鉴于您说 this.chara[i].addEventListener(...) 我猜 chara[i] 变量持有对DOM 元素.如果是这种情况，我猜它是一种没有 width 属性的元素类型.试试这个:

Given that you say this.chara[i].addEventListener(...) I'm guessing that the chara[i] variable holds a reference to a DOM element. If that is the case I'm guessing it is an element type that doesn't have a width property. Try this:

that.chara[i].style.width

https://developer.mozilla.org/en/CSS/width

这是我能为你做的最好的事情，但没有更多关于你得到什么错误以及如何调用 qwerty() 函数的信息......

That's the best I can do for you without more information about what error you're getting and how the qwerty() function is called...

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