如何在所有ajax请求完成后调用alert？

Question

我在代码中用jQuery和get做了几个请求。它看起来像：

$.get('address1', function() { ... }); 
$.get('address2', function() { ... }); 
$.get('address3', function() { ... }); 

// This code should be runned when all 3 requests are finished 
alert('Finished'); 

那么，还有检测是否还有处理请求和运行，只有当所有3个请求完成后标记代码的任何方式。

谢谢。

Answer 1

您可以使用deferred objects^[docs]在jQuery的1.5介绍：

$.when(
    $.get('address1', function() { ... }), 
    $.get('address2', function() { ... }), 
    $.get('address3', function() { ... }) 
).then(function() { 
    alert('Finished'); 
}); 

参考：jQuery.when

jQuery的学习中心有一个很好的introduction to deferred objects/promises。

Answer 2

var fin1 = false; 
var fin2 = false; 
var fin3 = false; 

$.ajax({ 
    url: "address1", 
    success: function(){ 
    fin1 = true; 
    fnUpdate(); 
    } 
}); 

$.ajax({ 
    url: "address2", 
    success: function(){ 
    fin2 = true; 
    fnUpdate(); 
    } 
}); 

$.ajax({ 
    url: "address3", 
    success: function(){ 
    fin3 = true; 
    fnUpdate(); 
    } 
}); 

function fnUpdate(){ 
    if(fin1 && fin2 && fin3){ 
    alert('fin'); 
    } 
} 

Answer 3

var count = 0; 
$.get('address1', function() { count++; ... }); 
$.get('address2', function() { count++; ... }); 
$.get('address3', function() { count++; ... }); 

var int = setInterval(function() { 
    if (count === 3) { 
     clearInterval(int); 
     alert('done'); 
    } 
}, 10); 

Answer 4

var isFinished = []; 

$.get('address1', function() { isFinshed.push["address1"]; allDone(); }); 
$.get('address2', function() { isFinshed.push["address2"]; allDone(); }); 
$.get('address3', function() { isFinshed.push["address3"]; allDone();}); 

var allDone = function(){ 
    if(isFinished.length < 3)return 

    alert('Finished'); 
};