在aurelia js中的回调函数(Callback function in aurelia js)

在aurelia js中的回调函数(Callback function in aurelia js)

我是aurelia js的新手。 在这里，我需要在aurelia js中进行回调。 这是我试过的代码， file.js

this.commonFunctions.get_alrdyShrdUser(this.alrdyshardAry,function(err,result){ if(!err){ console.log("err,result",err,result); this.sharedAlrdy = result; }else{ } });

commonFunctions

get_alrdyShrdUser(docids,callback){ this.httpValueConverter.call_http('sharing/users/list','POST',docids,'test') .then(data => { if(data.meta && data.meta.statusCode == 200) { return callback(null,data.sharedUsers) } }); }

这里一切正常，回调函数也返回值，但我不能赋值给aurelia varibale （ this.sharedAlrdy ）。它抛出错误， 无法设置未定义属性'sharedAlrdy' 。 那是否有其他方法可以实现？

Am new to aurelia js. Here, i need to do callback in aurelia js . Here is the code i tried, file.js

this.commonFunctions.get_alrdyShrdUser(this.alrdyshardAry,function(err,result){ if(!err){ console.log("err,result",err,result); this.sharedAlrdy = result; }else{ } });

commonFunctions

get_alrdyShrdUser(docids,callback){ this.httpValueConverter.call_http('sharing/users/list','POST',docids,'test') .then(data => { if(data.meta && data.meta.statusCode == 200) { return callback(null,data.sharedUsers) } }); }

Here all works fine, callback function also returned value, but i can't assign value to a aurelia varibale(this.sharedAlrdy).It throws error, Cannot set property 'sharedAlrdy' of undefined. Is that any other way to achieve?

最满意答案

这与Aurelia无关。 这只是一个典型的JavaScript问题。

由于您使用的是Aurelia，因此我认为这是ES6代码，并且您有箭头功能支持。 在函数回调中使用箭头函数，并且在捕获时不会遇到问题：

this.commonFunctions.get_alrdyShrdUser(this.alrdyshardAry, (err, result) => {
    if (!err) {
        console.log("err, result", err, result);
        this.sharedAlrdy = result;
    } else {

    }
});
 
 有关箭头函数和更多细节，请看一下MDN 。 
This has nothing to do with Aurelia. You are just having a typical JavaScript problem with this.
 
Since you are using Aurelia, I assume that is ES6 code and you have arrow function support. Use arrow function in function callbacks and you won't have problems with capturing this:
 
this.commonFunctions.get_alrdyShrdUser(this.alrdyshardAry, (err, result) => {
    if (!err) {
        console.log("err, result", err, result);
        this.sharedAlrdy = result;
    } else {

    }
});
 
For more details on arrow functions and this, take a look at MDN.