当我进入函数时,如何保持`this`的值？

Question

this当我进入函数时,如何保留我丢失之前值的值this

例如,在这种情况下,我如何才能访问testFunction.

admin = function()
{
    this.testFunction = function()
    {
    alert('hello');
    }

    this.test2Function = function()
    {
        $.ajax({
            url:'',
            success: function()
            {
                 this.testFunction();
                 // here I got an error undefined 
            }
        });
     }
}

我试图将这个值保持在这样的自变量上

this.self = this;

但不行

Answer 1

你需要使用一个闭包.在JavaScript中执行此操作的惯用方法是:

function foo(){
   //Store this in outer scoped variable.
   // It will be available to anything within this scope
   var that = this;

   innerCall(function(){
      that.doSomething();
   });
}