javascript - 嵌套的javascript函数丢失 "this"

Question

我有一个嵌套函数，它失去了“this”的正确范围

if(tabNav === true){

$("." + tabNavClass).show();
tabNavItem.first().addClass("active");//active class on first li
tabNavItem.each(function(i){
    $(this).attr("rel",(i + 1));
});                         

tabNavItem.on("click", function(e){

    tabNavClick();
    //this works, but i don't want it defined here. i want it in the tabNavClick() function
    //var data = $(this).attr("rel");
    //console.log(data);
    e.preventDefault();

});             

}           


//tab nav function          
function tabNavClick(){

// REGISTERS UNDEFINED HERE B/C LOSES SCOPE OF "THIS". FIX?!                    
var that = $(this);
var data = that.attr("rel");
console.log(data);

tabNavItem.removeClass("active");//remove existing active class

};

我已经尝试过 var that = $(this)，但这不起作用，而且我认为 .call 在这种情况下不起作用。我如何让 $(this).attr("rel"); 返回我想要的 rel # 值而不是 undefined？

Answer 1

将 $(this) 传递给函数

  tabNavClick($(this));

  function tabNavClick(obj){
     var that = obj;
     ....

此外，您可以将函数 tabNavClick 作为点击处理程序传递并获取事件

  tabNavItem.on("click",tabNavClick)

  function tabNavClick(e){
      e.preventDefault();
      var that=$(this);
   }