我想要一個(gè)帶有2種狀態(tài)的html數(shù)字文本框,當(dāng)聚焦時(shí),它必須顯示所有小數(shù)位,而當(dāng)聚焦丟失時(shí),僅顯示2個(gè)小數(shù).我?guī)缀鯇?shí)現(xiàn)了.
HTML:
<input data-bind="attr: { 'data-numericvalue': valueToRound}" class="numerictextbox" type="number"/>
Javascript:
var viewModel = { valueToRound: ko.observable(7.4267),};//NUMERIC TEXTBOX BEHAVIOUR$('.numerictextbox').focusout(function () { $(this).attr("data-numericvalue", this.value); //this line does not update the viewModel this.value = parseFloat($(this).attr("data-numericvalue")).toFixed(2);});$('.numerictextbox').focusin(function () { if ($(this).attr("data-numericvalue") !== undefined) this.value = $(this).attr("data-numericvalue");});ko.applyBindings(viewModel);
Jsfiddle:https://jsfiddle.net/7zzt3Lbf/64/
但是我的問題是,發(fā)生聚焦時(shí),它不會(huì)更新綁定屬性(在這種情況下為viewModel).這是我的代碼的簡(jiǎn)化版本,因此我希望它對(duì)我的實(shí)際場(chǎng)景中的許多屬性通用.
解決方法:
您混入了太多的jQuery ??
淘汰賽具有事件綁定和hasFocus綁定以處理UI輸入.
在下面的示例中,我創(chuàng)建了一個(gè)視圖模型,該模型具有可觀察到的隱藏realValue,該值存儲(chǔ)未修改的輸入.當(dāng)showDigits為false時(shí),displayValue將此數(shù)字限制為2位數(shù)字.
我使用過hasFocus來跟蹤我們是否要顯示整數(shù):它鏈接到showDigits.
var ViewModel = function() { this.showDigits = ko.observable(true); var realValue = ko.observable(6.32324261); this.displayValue = ko.computed({ read: function() { return this.showDigits() ? realValue() : parseFloat(realValue()).toFixed(2); }, write: realValue }, this);};ko.applyBindings(new ViewModel());
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script><input data-bind="value: displayValue, hasFocus: showDigits" type="number"/>
編輯:在注釋中,計(jì)算式的代碼過多了:這是將計(jì)算式的邏輯包裝在可重用的擴(kuò)展器中的方法:
ko.extenders.digitInput = function(target, option) { var realValue = target, showRealValue = ko.observable(false), displayValue = ko.computed({ read: function() { return showRealValue() ? realValue() : parseFloat(realValue()).toFixed(2); }, write: realValue }, this); displayValue.showRealValue = showRealValue; return displayValue;};var ViewModel = function() { this.value1 = ko.observable(6.452345).extend({ digitInput: true }); this.value2 = ko.observable(4.145).extend({ digitInput: true });};ko.applyBindings(new ViewModel());
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script><input data-bind="value: value1, hasFocus: value1.showRealValue" type="number"/><input data-bind="value: value2, hasFocus: value2.showRealValue" type="number"/>
來源:https://www.icode9.com/content-1-522901.html
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