Javascript jQuery ajax，等到 beforeSend 动画完成

jQuery ajax, wait until beforeSend animation finishes

提问by James

HTML & CSS:

HTML 和 CSS：

<a href="#">link</a>
<img src="http://2.bp.blogspot.com/_OIHTbzY7a8I/TOaiTKLqszI/AAAAAAAAAHM/eb3iiOqxzKg/s640/Auto_Audi_Audi_concept_car_005130_.jpg" />
<div></div>

img { display: none; }
a { display: block; }

JS:

JS：

$("a").click(function(){
    $.ajax({
        url: "test.php",
        contentType: "html",
        beforeSend: function(){
            $("img").fadeIn(600, function(){
                $("div").append(" | beforeSend finished | ");
            });
        },
        error: function(){
            $("div").append(" | error | ");
        }
    });
    return false
});

The problem is, errorfunction starts, before animation in beforeSendfunction finishes.

问题是，error函数开始之前，函数中的动画beforeSend完成。

Here is working example http://jsfiddle.net/H4Jtk/2/

这是工作示例http://jsfiddle.net/H4Jtk/2/

errorshould begin to work only when beforeSendis finished. How to do this?

error应该在beforeSend完成后才开始工作。这该怎么做？

I use beforeSendfunction to start animation of the blocks when ajax starts. I can't remove it.

beforeSend当ajax启动时，我使用函数来启动块的动画。我无法删除它。

Thanks.

谢谢。

回答by eyelidlessness

You can use a custom event to wait until the animation is complete, like this:

您可以使用自定义事件等待动画完成，如下所示：

$("a").click(function(){
    var img = $("img"),
        div = $("div");
    $.ajax({
        url: "test.php",
        contentType: "html",
        beforeSend: function(){
            img.fadeIn(600, function(){
                div.append(" | beforeSend finished | ");
                div.trigger("animationComplete");
            });
        },
        error: function(){
            if(img.is(':animated')) {
                div.one("animationComplete", function() {
                    div.append(" | error | ");
                });
            } else {
                div.append(" | error | ");
            }
        }
    });
    return false
});

Notes:

笔记：

1. jQuery.one()attaches an event handler that fires once and is then removed.
2. jQuery.is(':animated')is a custom selector provided by jQuery to determine if an element is animated using jQuery's built-in animation methods (eg fadeIn).

1. jQuery.one()附加一个事件处理程序，该事件处理程序触发一次然后被删除。
2. jQuery.is(':animated')是 jQuery 提供的自定义选择器，用于确定元素是否使用 jQuery 的内置动画方法（例如fadeIn）进行动画处理。

New jsFiddle: http://jsfiddle.net/pgjHx/

新的 jsFiddle：http: //jsfiddle.net/pgjHx/

---

---

In the comments, Happy has asked how to handle multiple animations. One way would be to add a condition to the animationCompleteevent handler to see if animation is ongoing. For example:

在评论中，Happy 询问了如何处理多个动画。一种方法是向animationComplete事件处理程序添加条件以查看动画是否正在进行。例如：

$("a").click(function(){
    var img = $("img"),
        div = $("div");

    $.ajax({
        url: "test.php",
        contentType: "html",
        beforeSend: function(){
            img.fadeIn(600, function(){
                div.append(" | beforeSend finished | ");
                div.trigger("animationComplete");
            });

            // Add another animation just to demonstrate waiting for more than one animation
            img.animate({
                marginTop: '-=5',
                opacity: '-=.5'
            }, 700, function() {    
                div.trigger("animationComplete");
            });
        },
        error: function(){
            if(img.is(":animated")) {
                // Note I've switched to bind, because it shouldn't be unbound
                // until all animations complete
                div.bind("animationComplete", function() {
                    if(img.is(":animated")) {
                        return;
                    }
                    div.append(" | error | ");
                    div.unbind("animationComplete");
                });
            } else {
                div.append(" | error | ");
            }
        }
    });
    return false
});

回答by Praveen Prasad

you can do this

你可以这样做

//run your animation on link click, and when animation gets completed, // then start your ajax request.

//在链接点击时运行你的动画，当动画完成时，//然后开始你的ajax请求。

$("a").click(function () {
    $("img").fadeIn(600, function () {
        $("div").append(" | beforeSend finished | ");
         $.ajax({
                    url: "test.php",
                    contentType: "html",
                    error: function () {
                        $("div").append(" | error | ");
                    }
                });
                return false
            });
    });
});

回答by Pointy

The thing is that "beforeSend" isfinished - it will exit long before that "fadeIn" finishes. I don't know what you're trying to accomplish so it's hard to offer a solution. You'd have to wait to start the ajax operation until afterthe animation sequence (the "fadeIn") completes if you wanted to guarantee that to happen first.

问题是，“beforeSend”是成品-长则退出前的“淡入”结束。我不知道您要完成什么，因此很难提供解决方案。如果您想确保首先发生，则必须等到动画序列（“淡入淡出”）完成后才能开始 ajax 操作。