Question

我创建了一个仅接受数字和带小数的数字的指令。我的代码是

import { Directive, ElementRef, HostListener } from '@angular/core';

@Directive({
    selector: '[number-only]'
})
export class NumberOnlyDirective {
    // Allow decimal numbers and negative values
    private regex: RegExp = new RegExp(/^-?[0-9]+(\.){0,1}([0-9]*){0,1}$/g);
    // Allow key codes for special events. Reflect :
    // Backspace, tab, end, home
    private specialKeys: Array<string> = ['Backspace', 'Tab', 'End', 'Home', '-', "ArrowLeft", "ArrowRight", "ArrowUp", "ArrowDown", "Delete"];

    constructor(private el: ElementRef) {
    }
    @HostListener('keydown', ['$event'])
    onKeyDown(event: KeyboardEvent) {
        // Allow Backspace, tab, end, and home keys
        if (this.specialKeys.indexOf(event.key) !== -1) {
            return;
        }
        let current: string = this.el.nativeElement.value;
        let next: string = current.concat(event.key);
        if (next && !String(next).match(this.regex)) {
            event.preventDefault();
        }
    }

}

我将此指令用作

<input type="number" min="0" class="form-control" number-only />

问题是此输入元素接受两个小数，例如 5..35 。我已经测试过正则表达式here。很好。

Answer 1

尝试使用此RegEx：（/ ^ \ d *。？\ d {0,2} $ / g）

仅限角度数字的指令，接受两个小数点（0 ..）

1 个答案: