如何知道所有 ajax 调用何时完成

问题描述

我有一个带有行的表格样式页面.每行都有一个复选框.我可以选择所有/许多复选框并单击提交"，然后对每一行进行 Jquery ajax 调用.

I have a table style page with rows. Each row has a checkbox. I can select all/many checkboxes and click "submit" and what is does is a Jquery ajax call for each row.

基本上我每行都有一个表单，我遍历所有选中的行并提交执行 jquery ajax 调用的表单.

Basically I have a form for each row and I iterate over all the checked rows and submit that form which does the jquery ajax call.

所以我有一个按钮:

       $("input:checked").parent("form").submit();

那么每一行都有:

            <form name="MyForm<%=i%>" action="javascript:processRow(<%=i%>)" method="post" style="margin:0px;">
                <input type="checkbox" name="X" value="XChecked"/>
                <input type="hidden" id="XNumber<%=i%>" name="X<%=i%>" value="<%=XNumber%>"/>
                <input type="hidden" id="XId<%=i%>" name="XId<%=i%>" value="<%=XNumber%>"/>
                <input type="hidden" id="XAmt<%=i%>" name="XAmt<%=i%>" value="<%=XAmount%>"/>
                <input type="hidden" name="X" value="rXChecked"/>
            </form>

此表单提交给 processRow:

This form submits to processRow:

   function processRow(rowNum)
   {
        var Amount = $('#XAmt'+rowNum).val();
        var XId = $('#XId'+rowNum).val();
        var XNum = $('#OrderNumber'+rowNum).val();
        var queryString = "xAmt=" + "1.00" + "&xNumber=" + OrdNum + "&xId=" + xId;


        $('#coda_'+rowNum).removeClass("loader");
        $('#coda_'+rowNum).addClass("loading");


        $.ajax({
          url: "x.asp",
          cache: false,
          type:  "POST",
          data:  queryString,
          success: function(html){
            $('#result_'+rowNum).empty().append(html);
            $('#coda_'+rowNum).removeClass("loading");
            $('#coda_'+rowNum).addClass("loader");
          }
        });
   }

我想知道的是，有没有一种方法可以判断我的所有 Ajax 调用是否已完成.原因是想要在所有这些调用发生时启用/禁用提交按钮.

What I wanted to know is, from this is there a way I can tell if all my Ajax calls are complete. Reason being that want to enable/disable the submit button while all these calls are taking place.

谢谢，请注意，由于应用程序的敏感性，我不得不修改我的变量名称，因此其中很多可能会重复.

Thanks and please note that I had to mangle my variable names due to the sensitivity of the application, so many of them may be duplicated.

推荐答案

简单的方法

最简单的方法是使用 .ajaxStop() 事件处理程序:

The easy way

The easiest way is to use the .ajaxStop() event handler:

$(document).ajaxStop(function() {
  // place code to be executed on completion of last outstanding ajax call here
});

艰难的道路

您还可以手动检测是否有任何 ajax 调用仍处于活动状态:

The hard way

You can also manually detect if any ajax call is still active:

创建一个包含活动 Ajax 连接数的变量:

Create a variable containing number of active Ajax connections:

var activeAjaxConnections = 0;

就在打开新的 Ajax 连接之前增加那个变量

just before opening new Ajax connection increment that variable

$.ajax({
  beforeSend: function(xhr) {
    activeAjaxConnections++;
  },
  url (...)

在 success 部分检查该变量是否为零(如果是，则最后一个连接已完成)

in success part check if that variable equals to zero (if so, the last connection has finished)

success: function(html){
  activeAjaxConnections--;
  $('#result_'+rowNum).empty().append(html);
  $('#coda_'+rowNum).removeClass("loading");
  $('#coda_'+rowNum).addClass("loader");
  if (0 == activeAjaxConnections) {
    // this was the last Ajax connection, do the thing
  }
},
error: function(xhr, errDesc, exception) {
  activeAjaxConnections--;
  if (0 == activeAjaxConnections) {
    // this was the last Ajax connection, do the thing
  }
}

如您所见，我还添加了错误返回检查

As you can see, I've added also checking for return with error

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