问等待，直到使用$.when()执行所有操作(即使失败)

EN

$.when(deferred1, deferred2).then(function() {
    // Called only after both deferred are resolved
}, function() {
    // Called immediately after one of the deferreds is rejected
});

var deferred1Complete = false;
var deferred2Complete = false;

function callback() {
    if (deferred1Complete && deferred2Complete) {
        // Execute after both deferred are either resolved or rejected
    }
}

deferred1.always(function() {
    deferred1Complete = true;
    callback();
});

deferred2.always(function() {
    deferred2Complete = true;
    callback();
});