【发布时间】：2019-06-20 21:40:57
【问题描述】：
我正在尝试使用 Knockout 实现自动完成，自动完成示例取自：https://www.w3schools.com/howto/howto_js_autocomplete.asp
我正在尝试将所有 JavaScript/knockout 保存在一个单独的文件中，这是迄今为止在 Knockout 文件中的样子：
var ViewModel = function () {
var self = this;
this.counties = ko.observableArray([]);
this.getCounties = function () {
self.counties([]);
$.ajax({
url: '/Search/ByCounty',
type: 'GET',
success: function (data) {
if (data && data.length > 0) {
for (var i = 0; i < data.length; i++) {
var obj = data[i];
self.counties.push(obj);
}
}
},
error: function (error) {
console.log(error);
}
});
};
function autocomplete(inp, arr) {
/*the autocomplete function takes two arguments,
the text field element and an array of possible autocompleted values:*/
var currentFocus;
/*execute a function when someone writes in the text field:*/
inp.addEventListener("input", function (e) {
var a, b, i, val = this.value;
/*close any already open lists of autocompleted values*/
closeAllLists();
if (!val) { return false; }
currentFocus = -1;
/*create a DIV element that will contain the items (values):*/
a = document.createElement("DIV");
a.setAttribute("id", this.id + "autocomplete-list");
a.setAttribute("class", "autocomplete-items");
/*append the DIV element as a child of the autocomplete container:*/
this.parentNode.appendChild(a);
/*for each item in the array...*/
for (i = 0; i < arr.length; i++) {
/*check if the item starts with the same letters as the text field value:*/
if (arr[i].substr(0, val.length).toUpperCase() == val.toUpperCase()) {
/*create a DIV element for each matching element:*/
b = document.createElement("DIV");
/*make the matching letters bold:*/
b.innerHTML = "<strong>" + arr[i].substr(0, val.length) + "</strong>";
b.innerHTML += arr[i].substr(val.length);
/*insert a input field that will hold the current array item's value:*/
b.innerHTML += "<input type='hidden' value='" + arr[i] + "'>";
/*execute a function when someone clicks on the item value (DIV element):*/
b.addEventListener("click", function (e) {
/*insert the value for the autocomplete text field:*/
inp.value = this.getElementsByTagName("input")[0].value;
/*close the list of autocompleted values,
(or any other open lists of autocompleted values:*/
closeAllLists();
});
a.appendChild(b);
}
}
});
/*execute a function presses a key on the keyboard:*/
inp.addEventListener("keydown", function (e) {
var x = document.getElementById(this.id + "autocomplete-list");
if (x) x = x.getElementsByTagName("div");
if (e.keyCode === 40) {
/*If the arrow DOWN key is pressed,
increase the currentFocus variable:*/
currentFocus++;
/*and and make the current item more visible:*/
addActive(x);
} else if (e.keyCode === 38) { //up
/*If the arrow UP key is pressed,
decrease the currentFocus variable:*/
currentFocus--;
/*and and make the current item more visible:*/
addActive(x);
} else if (e.keyCode === 13) {
/*If the ENTER key is pressed, prevent the form from being submitted,*/
e.preventDefault();
if (currentFocus > -1) {
/*and simulate a click on the "active" item:*/
if (x) x[currentFocus].click();
}
}
});
function addActive(x) {
/*a function to classify an item as "active":*/
if (!x) return false;
/*start by removing the "active" class on all items:*/
removeActive(x);
if (currentFocus >= x.length) currentFocus = 0;
if (currentFocus < 0) currentFocus = (x.length - 1);
/*add class "autocomplete-active":*/
x[currentFocus].classList.add("autocomplete-active");
}
function removeActive(x) {
/*a function to remove the "active" class from all autocomplete items:*/
for (var i = 0; i < x.length; i++) {
x[i].classList.remove("autocomplete-active");
}
}
function closeAllLists(elmnt) {
/*close all autocomplete lists in the document,
except the one passed as an argument:*/
var x = document.getElementsByClassName("autocomplete-items");
for (var i = 0; i < x.length; i++) {
if (elmnt !== x[i] && elmnt !== inp) {
x[i].parentNode.removeChild(x[i]);
}
}
}
/*execute a function when someone clicks in the document:*/
document.addEventListener("click", function (e) {
closeAllLists(e.target);
});
}
/*initiate the autocomplete function on the "myInput" element, and pass along the countries array as possible autocomplete values:*/
autocomplete(document.getElementById("myInput"), self.counties());
};
ko.applyBindings(new ViewModel());
使用上面我使用函数 getCounties 调用的 ajax 调用是可以的，因为这会带回我的 json 并将其放入数组中。但是，在我看来，这些值不会出现在自动完成输入中，也没有错误。我认为的 html 位于一个单独的页面上，如下所示：
<div style="margin-top:10px;" class="row">
<div class="col">
<form autocomplete="off">
<div class="autocomplete" style="width:300px;">
<input id="myInput" type="text" name="myCounty" placeholder="County">
</div>
<button type="button" class="btn btn-primary" onclick="search('county')">Go</button>
</form>
</div>
</div>
我猜我的 Knockout 文件中的这一行一定不正确？...或者我的绑定在某处关闭了？..
autocomplete(document.getElementById("myInput"), self.counties());
【问题讨论】：
标签： javascript model-view-controller data-binding knockout.js autocomplete