Question

如果我使用此代码，为什么“doStuff”警报的范围已更改？有没有办法可以确保范围是我的对象而不是Window对象？

以下是jsfiddle中的相同代码。

(function ($) {
    var c$ = {};

    c$.TestScope = function () {

        this.doAjax = function (onComplete) {
            var self = this;
            $.ajax({
                url: 'badurl',
                complete: function (data) {
                    alert('doAjax2 self === c$.oTestScope: ' + (self === c$.oTestScope).toString());
                    onComplete(data);
                }
            });
            alert('doAjax1 self === c$.oTestScope: ' + (self === c$.oTestScope).toString());  
        };

        this.doStuff = function (data) {
            var self = this;
            alert('doStuff self === c$.oTestScope: ' + (self === c$.oTestScope).toString());
        }

    };

    c$.oTestScope = new c$.TestScope();
    c$.oTestScope.doAjax(c$.oTestScope.doStuff);
})(jQuery);

Answer 1

您应该能够将this值指定为$.ajax()参数中的上下文：

var c$ = {};

c$.TestScope = function() {

    this.doAjax = function(onComplete) {

        alert('doAjax1 this === c$.oTestScope: ' + (this === c$.oTestScope).toString());

        $.ajax({
            url: 'badurl',
            context: this,
            complete: function(data) {
                alert('doAjax2 this === c$.oTestScope: ' + (this === c$.oTestScope).toString());
                onComplete.call(this, data);
            }
        });
    };

    this.doStuff = function(data) {
        alert('doStuff this === c$.oTestScope: ' + (this === c$.oTestScope).toString());
    }

};

c$.oTestScope = new c$.TestScope();
c$.oTestScope.doAjax(c$.oTestScope.doStuff);

修改我为此做了fiddle并验证它是否正常运行。有一个额外的self参数，或者不得不用闭包来保存你的变量。

您缺少的部分内容是调用onComplete.call(this, data)来调用doStuff()。

Answer 2

我已修改您的代码以将对this的引用传递到doStuff（）代码。

(function ($) {
    var c$ = {};

    c$.TestScope = function () {

        this.doAjax = function (onComplete) {
            var self = this;
            $.ajax({
                url: 'badurl',
                complete: function (data) {
                    alert('doAjax2 self === c$.oTestScope: ' + (self === c$.oTestScope).toString());
                    onComplete(data,self);
                }
            });
            alert('doAjax1 self === c$.oTestScope: ' + (self === c$.oTestScope).toString());  
        };

        this.doStuff = function (data,thisRef) {
            var self = thisRef;
            alert('doStuff self === c$.oTestScope: ' + (self === c$.oTestScope).toString());
        }

    };

    c$.oTestScope = new c$.TestScope();
    c$.oTestScope.doAjax(c$.oTestScope.doStuff);
})(jQuery);

$ .ajax回调函数中的范围

2 个答案: