我在html页面上有很多输入框。我想限制用户输入2位小数后的任何数字。
目前尝试应用html 5输入Step =＆＃34; 0.00＆＃34;但是没有用。
任何打字稿解决方案也没问题
答案 0 :(得分：3)
我使用@pipe
获得了解决方案import { Directive,Input,Inject, HostListener, ElementRef, OnInit } from "@angular/core";
const PADDING = "000000";
@Pipe({ name: "CurrencyPipe" })
export class CurrencyPipe implements PipeTransform {
transform(value: any, args: string[]): any {
var clean = value.replace(/[^-0-9\.]/g, '');
var negativeCheck = clean.split('-');
var decimalCheck = clean.split('.');
if (negativeCheck[1] != undefined) {
negativeCheck[1] = negativeCheck[1].slice(0, negativeCheck[1].length);
clean = negativeCheck[0] + '-' + negativeCheck[1];
if (negativeCheck[0].length > 0) {
clean = negativeCheck[0];
}
}
if (decimalCheck[1] != undefined) {
decimalCheck[1] = decimalCheck[1].slice(0, 2);
clean = decimalCheck[0] + '.' + decimalCheck[1];
}
return clean;
}
parse(value: string, fractionSize: number = 2): string {
var clean = value.replace(/[^-0-9\.]/g, '');
var negativeCheck = clean.split('-');
var decimalCheck = clean.split('.');
if (negativeCheck[1] != undefined) {
negativeCheck[1] = negativeCheck[1].slice(0, negativeCheck[1].length);
clean = negativeCheck[0] + '-' + negativeCheck[1];
if (negativeCheck[0].length > 0) {
clean = negativeCheck[0];
}
}
if (decimalCheck[1] != undefined) {
decimalCheck[1] = decimalCheck[1].slice(0, 2);
clean = decimalCheck[0] + '.' + decimalCheck[1];
}
return clean;
}
}
和管道在我的指令中延伸。
import { Directive, Input, Inject, HostListener, OnChanges, ElementRef, Renderer, AfterViewInit, OnInit } from "@angular/core";
import { CurrencyPipe } from '../../shared/pipe/orderby';
@Directive({ selector: "[CurrencyFormatter]" })
export class CurrencyFormatterDirective {
private el: HTMLInputElement;
constructor(
private elementRef: ElementRef,
private currencyPipe: CurrencyPipe
) {
this.el = this.elementRef.nativeElement;
}
ngOnInit() {
this.el.value = this.currencyPipe.parse(this.el.value);
}
@HostListener("focus", ["$event.target.value"])
onFocus(value) {
this.el.value = this.currencyPipe.parse(value); // opossite of transform
}
@HostListener("blur", ["$event.target.value"])
onBlur(value) {
this.el.value = this.currencyPipe.parse(value);
}
@HostListener("keyup", ["$event.target.value"])
onKeyUp(value) {
this.el.value = this.currencyPipe.parse(value);
}
}
组件的导入指令
import { CurrencyFormatterDirective } from '../../shared/directive/showOnRowHover';
import { CurrencyPipe } from '../../shared/pipe/orderby';
providers: [CurrencyPipe,
CurrencyFormatterDirective]
关于你的html输入的指令
<input type="text" [(ngModel)]="invoiceDetail.InvoiceAmount" class="form-control" placeholder="Enter invoice amount"
CurrencyFormatter>
答案 1 :(得分：3)
请参阅Plnkr中的以下指令演示。
您可以使用以下指令实现此目的：
import { Directive, ElementRef, HostListener, Input } from '@angular/core';
@Directive({
selector: '[OnlyNumber]'
})
export class OnlyNumber {
elemRef: ElementRef
constructor(private el: ElementRef) {
this.elemRef = el
}
@Input() OnlyNumber: boolean;
@Input() DecimalPlaces: string;
@Input() minValue: string;
@Input() maxValue: string;
@HostListener('keydown', ['$event']) onKeyDown(event) {
let e = <KeyboardEvent> event;
if (this.OnlyNumber) {
if ([46, 8, 9, 27, 13, 110, 190].indexOf(e.keyCode) !== -1 ||
// Allow: Ctrl+A
(e.keyCode == 65 && e.ctrlKey === true) ||
// Allow: Ctrl+C
(e.keyCode == 67 && e.ctrlKey === true) ||
// Allow: Ctrl+X
(e.keyCode == 88 && e.ctrlKey === true) ||
// Allow: home, end, left, right
(e.keyCode >= 35 && e.keyCode <= 39)) {
// let it happen, don't do anything
return;
}
// Ensure that it is a number and stop the keypress
if ((e.shiftKey || (e.keyCode < 48 || e.keyCode > 57)) && (e.keyCode < 96 || e.keyCode > 105)) {
e.preventDefault();
}
}
}
@HostListener('keypress', ['$event']) onKeyPress(event) {
let e = <any> event
let valInFloat: number = parseFloat(e.target.value)
if(this.minValue.length) {
// (isNaN(valInFloat) && e.key === "0") - When user enters value for first time valInFloat will be NaN, e.key condition is
// because I didn't want user to enter anything below 1.
// NOTE: You might want to remove it if you want to accept 0
if( valInFloat < parseFloat(this.minValue) || (isNaN(valInFloat) && e.key === "0") ) {
e.preventDefault();
}
}
if(this.maxValue.length) {
if(valInFloat > parseFloat(this.maxValue)) {
e.preventDefault();
}
}
if (this.DecimalPlaces) {
let currentCursorPos: number = -1;
if (typeof this.elemRef.nativeElement.selectionStart == "number") {
currentCursorPos = this.elemRef.nativeElement.selectionStart;
} else {
// Probably an old IE browser
console.log("This browser doesn't support selectionStart");
}
let dotLength: number = e.target.value.replace(/[^\.]/g, '').length
// If user has not entered a dot(.) e.target.value.split(".")[1] will be undefined
let decimalLength = e.target.value.split(".")[1] ? e.target.value.split(".")[1].length : 0;
// (this.DecimalPlaces - 1) because we don't get decimalLength including currently pressed character
// currentCursorPos > e.target.value.indexOf(".") because we must allow user's to enter value before dot(.)
// Checking Backspace etc.. keys because firefox doesn't pressing them while chrome does by default
if( dotLength > 1 || (dotLength === 1 && e.key === ".") || (decimalLength > (parseInt(this.DecimalPlaces) - 1) &&
currentCursorPos > e.target.value.indexOf(".")) && ["Backspace", "ArrowLeft", "ArrowRight"].indexOf(e.key) === -1 ) {
e.preventDefault();
}
}
}
}
HTML用法如下：
<input type="text" OnlyNumber="true" DecimalPlaces="2" minValue="1.00" maxValue="999999999.00">
如果您发现任何错误，请在下面的评论中告诉我。
P.S：该指令改进了answer以验证小数点的工作。
答案 2 :(得分：-1)
<input type='number' step='0.01' value='0.00' placeholder='0.00' />
请勿使用Step使用step，如果您仍然需要旧浏览器的支持，则可以选择相同的javascript代码