javascript – 为什么即使调用成功,Jquery $.ajax也会在函数调用时触发所有statusCode

嘿家伙我有一个简单的Jquery ajax函数调用,看起来像这样.

function getUsers(){
    var jqxhr = $.ajax({
        url: "../assets/js/data/users.json",
        type: "GET",
        cache: true,
        dataType: "json",
        statusCode: { 
            404: handleError404("Error at getUsers();"),
            500: handleError500("Error at getUsers();")
        },
        success: function (data) {
            $.each(data, function(index, element) {
                console.log(element.name);
            });
        }
    });
}

错误句柄函数看起来像这样.

function handleError500(customMsg){
    alert("Oops, there was an error: 500");
    console.log("ERROR: 500 | "+customMsg);
}

function handleError404(customMsg){
    alert("Oops, there was an error: 404");
    console.log("ERROR: 404 | "+customMsg);
}

由于一些奇怪的原因,即使成功调用没有任何错误500或404,statusCode函数也会被触发.

有任何想法吗？谢谢.

解决方法:

这是一个常见的Javascript问题,但你实际上是在解雇这些功能！

()之后名称将实际调用该函数.

404: handleError404() // <-- it calls it immidiately

你需要做的是创建一个匿名函数,它将在错误实际发生时稍后调用,其中的内部函数将调用你的函数.

    statusCode: { 
        404: function () { // <-- anonymous function won't get called until it needs to
            handleError404("Error at getUsers();")
        },
        500: function () { 
            handleError500("Error at getUsers();")
        }
    },

Side note: If you weren’t passing in parameters to your function,
you Could actually ommit the anonymous function function () { /*
function call */ } part, and just call your function!

statusCode: {
    404: handleErrors, // since no parameters are passed, this Could be done
    500: handleErrors
}