Question

$.each(data, function (index, info) {
                    var a = info.notes;
                    var b = info.permission;
                    //var c = null;
                    var c = null;
                    $.ajax({
                        url: "assets/getExpiration.php?expiry=" + info.expiration,
                        type: "GET",
                        dataType: "text"
                    }, function(data){
                        c = data;
                    });
                    var z = null;
                    switch(info.stars) {
                        case 0: z = "<img src='assets/img/0star.png'/>"; break;
                        case 1: z = "<img src='assets/img/1star.png'/>"; break;
                        case 2: z = "<img src='assets/img/2star.png'/>"; break;
                        case 3: z = "<img src='assets/img/3star.png'/>"; break;
                        default: z = "<label class='label label-danger'>" + c + "</label>"; break; 
                    }

                    var notes = a.length > 0 ? "<i class='fa fa-file'></i>" : "";
                    var permission = b.length > 0 ? "<i class='fa fa-warning'></i>" : "";
                    if (info.status == 'EXPIRED') {
                        $("#pendingCall" + info.callNum).append("<button onclick=\"loadPlayer('" + info.playerTag+ "', '" + info.status + "', "+ info.callNum +")\"class='btn btn-danger disabled'>" + info.username  + " " + permission + " " + notes + "</button>");
                    } else {
                        $("#pendingCall" + info.callNum).append("<button onclick=\"loadPlayer('" + info.playerTag+ "', '" + info.status + "', "+ info.callNum +")\"class='btn btn-primary'>" + info.username + " " + permission + " " + notes + "<br> " + z + "</button>");

                    }
                });

c未被编辑。但是当我在console.log(c)内$.ajax()时，它给了我正确的价值。但是，当我console.log()之外的$.ajax()时，它会给我'null'。我查了许多很多很多stackoverflow类似的问题，但所有的答案都没有用，或者我可能只是遗漏了一些东西。

Answer 1

您是否假设代码来自：

var z = null;
switch(info.stars) {....

会等待你的ajax请求完成吗？如果是这样，那就不太合适了。

Ajax将异步激活请求，而其余代码继续执行（假设您没有指定它应该同步运行＆lt; - 这不是一个好主意。）

如果你想使用AJAX返回的值，你需要将这个代码添加到ajax选项成功属性或类似的属性，它将在完成时执行。

Answer 2

$ .ajax是一种即时返回的异步方法，但会在后台完成HTTP请求后运行成功和错误函数。

您需要将代码移动到$ .ajax方法中调用的自己的函数中。以下是一个例子。

$.ajax({
    url: "assets/getExpiration.php?expiry=" + info.expiration,
    type: "GET",
    dataType: "text"
}, function (data) {
    c = data;
    var z = null;
    switch(info.stars) {
        case 0: z = "<img src='assets/img/0star.png'/>"; break;
        case 1: z = "<img src='assets/img/1star.png'/>"; break;
        case 2: z = "<img src='assets/img/2star.png'/>"; break;
        case 3: z = "<img src='assets/img/3star.png'/>"; break;
        default: z = "<label class='label label-danger'>" + c + "</label>"; break; 
    }

    var notes = a.length > 0 ? "<i class='fa fa-file'></i>" : "";
    var permission = b.length > 0 ? "<i class='fa fa-warning'></i>" : "";
    if (info.status == 'EXPIRED') {
        $("#pendingCall" + info.callNum).append("<button onclick=\"loadPlayer('" + info.playerTag+ "', '" + info.status + "', "+ info.callNum +")\"class='btn btn-danger disabled'>" + info.username  + " " + permission + " " + notes + "</button>");
    } else {
        $("#pendingCall" + info.callNum).append("<button onclick=\"loadPlayer('" + info.playerTag+ "', '" + info.status + "', "+ info.callNum +")\"class='btn btn-primary'>" + info.username + " " + permission + " " + notes + "<br> " + z + "</button>");

    }
});

AJAX不会覆盖全局变量JQUERY

2 个答案: