Question

我有2个变量声明为mtn和atn，其值根据API ajax响应填充。

现在，我正在使用API响应返回的值分配mtn和atn变量，在我的情况下，因为mtn将为null，而atn具有10位数字。所以我使用atn的子字符串分配atn1，atn2，atn3，而mtn1，mtn2和mtn3不受影响，如下面的代码片段所示。

var ViewModel = {
mtn: null,
atn: null,
mtn1: ko.observable(null),
mtn2: ko.observable(null),
mtn3: ko.observable(null),
atn1: ko.observable(null),
atn2: ko.observable(null),
atn3: ko.observable(null)
}
// Ajax API call happens and assigns ViewModel.mtn and ViewModel.atn
if (ViewModel.mtn != null && ViewModel.mtn.length == 10) { //This condition is not true because ViewModel.mtn is coming as null in case and so mtn1, mtn2 and mtn3 observables are untouched
ViewModel.mtn1 = ViewModel.mtn.substring(0, 3);
ViewModel.mtn2 = ViewModel.mtn.substring(3, 6);
ViewModel.mtn3 = ViewModel.mtn.substring(6, 10);
}
if (ViewModel.atn != null && ViewModel.atn.length == 10) {
ViewModel.atn1 = ViewModel.atn.substring(0, 3);
ViewModel.atn2 = ViewModel.atn.substring(3, 6);
ViewModel.atn3 = ViewModel.atn.substring(6, 10);
}
ko.applyBindings(ViewModel);

// Click event happens from View and Business logic UI validations take place below
processClick: function() {
     .var strmtn = ViewModel.mtn1 + ViewModel.mtn2 + ViewModel.mtn3; // This is not working and throwing error and only ViewModel.mtn1() is working
      var stratn = ViewModel.atn1 + ViewModel.atn2 + ViewModel.atn3; // This is working fine but ViewModel.atn1() is not working.

我认为访问atn1作为ViewModel.atn1的方法正在工作，而访问mtn1作为ViewModel.mtn1的方法不起作用是因为为atn1重新分配了observable，而没有触及mtn1。

那么我怎么知道调用可观察值的访问方法，因为我不知道我的可观察量是否被触及了？：（

P.S：我正在使用的Knockout 3.x版本中出现此问题。我刚刚添加了2.x版本。

Answer 1

observable是一个getter-setter函数。要设置其内容，请执行

ViewModel.mtn1(ViewModel.mtn.substring(0, 3));

要获取其内容，请执行

value = ViewModel.mtn1();

在设置值之前和之后访问可观察变量不起作用

1 个答案: