使用knockout.js將兩個數組綁定到彼此

Question

我有一個ViewModel包含兩個數組：arr1和arr2。我想arr2準確地包含arr1包含的內容。我怎樣才能做到這一點？

var myViewModel = function() { 
    this.arr1 = ko.observableArray([]); 
    this.arr2 = ko.observableArray(this.arr1); //Doesn't work - I need to bind arr2 to changes in arr1 
} 

Answer 1

如果你想存儲參考數組元素使用時應拆開包裝觀察到：

var myViewModel = function() { 
    this.arr1 = ko.observableArray([]); 
    this.arr2 = ko.observableArray(this.arr1()); 
} 

如果要克隆數組使用數組Slice功能：如果你想先複製

var myViewModel = function() { 
    this.arr1 = ko.observableArray([]); 
    this.arr2 = ko.observableArray(this.arr1.slice(0)); 
} 

Answer 2

陣列到第二個一次您可以打包arrya的副本，使用函數ko.toJS或ko.toJSON

var myViewModel = function() { 
    this.arr1 = ko.observableArray([]); 
    this.arr2 = ko.observableArray(ko.toJS(this.arr1)); 
} 

如果你想每次更改第二個數組，首當是改變了使用用戶

var myViewModel = function() { 
    this.arr1 = ko.observableArray([]); 
    this.arr2 = ko.observableArray([]); 
    this.arr2.subscribe(function(newValue) { 
     this.arr2(ko.toJS(this.arr1)); 
    }); 
}