将'this'对象传递给$ http服务的'then'回调函数 [英] Passing 'this' object to the 'then' callback function of $http service

问题描述

我在将'this'对象传递给$ http服务的'then'回调函数时遇到问题，如下所示

I am having problems passing 'this' object to the 'then' callback function of $http service as shown below

var Product = function(){
    this.name = "putty";
    this.price = 760;
    $http.post(url, data).then.call(this, function(){
        this.saved = true;
    });
};

当我在语句this.saved = true中检查 this对象时，我意识到这是指向全局对象而不是预期的Product实例，因为我可以使用 then.call（this，function（）{...）代替 then（this，function（）{...

When I inspect 'this' object in the statement this.saved = true, I realise that it is pointing to the global object and not to an instance of Product as expected since I have "then.call(this, function(){..." instead of "then(this, function(){..." as can be seen in my code. Any help please???

推荐答案

在使用 then.call（this， function（）{}）; ，您正在调用 then 函数作为 this ，但这不会影响您传递的实际回调函数的 this 值。

When using then.call(this, function(){}); you're calling the then function as this, but that will not affect the this value of the actual callback function that you are passing.

如果要将 this 绑定到回调，可以使用 bind ：

If you want to bind this to the callback, you can use bind:

$http.post(url, data).then(function(){
    this.saved = true;
}.bind(this));

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