Angular 6 在选择选项中显示过去 12 个月的年份倒序 [英] Angular 6 show last 12 months with year reverse order in select option
问题描述
我将尝试在 select
选项中动态显示过去 12 个月和年份.
例如:
<块引用>如果当前月份是 March
和年份 2021
,我需要显示 March-2021
是过去 12 个月之后的第一个选项下一个选项以相反的顺序.如果当前月份是 April
,则将第一个选项显示为April-2021"
appcomponent.ts
import { Component, VERSION } from '@angular/core';@成分({选择器:'我的应用',templateUrl: './app.component.html',styleUrls: ['./app.component.css']})导出类 AppComponent {名称 = '角度' + VERSION.major;月 = [{id:'01', name:'Jan'}, {id:'02', name:'Feb'},{id:'03', name:'Mar'},{id:'04', name:'Apr'},{id:'05', name:'May'},{id:'06', name:'Jun'},{id:'07', name:'Jul'},{id:'08', name:'Aug'},{id:'09', name:'Sep'},{id:'10', name:'Oct'},{id:'11',name:'Nav'},{id:'12', name:'Dec'},];
appcomponent.html
请试试这个.您可以轻松地从日期对象中一一减去月份,日期对象会相应地更新,如下所示
app.component.ts
import { Component, VERSION } from "@angular/core";@成分({选择器:我的应用程序",templateUrl: "./app.component.html",styleUrls: [./app.component.css"]})导出类 AppComponent {日期 = [];构造函数(){for (var i = 0; i <12; i++) {var d = 新日期();d.setMonth(d.getMonth() - i);var month = d.toLocaleString("default", { month: "long" });var 年 = d.getFullYear();var monthNo=d.getMonth();如果(月号<9){this.dates.push( {month:"0"+(monthNo+1),date:month+"-"+year});}别的{this.dates.push( {month:(monthNo+1),date:month+"-"+year});}}}名称=角度"+ VERSION.major;月 = [{ id:01",姓名:Jan";},{ id: 02", name: Feb";},{ id:03",名称:Mar";},{ id: 04", name: Apr";},{ id: 05", name: May";},{ id: "06", name: "Jun";},{ id:07",名称:Jul";},{ id: 08", name: Aug";},{ id:09",名称:Sep";},{ id:10",名称:Oct";},{ ID:11",名称:导航";},{ id:12",名称:Dec";}];选择更改(e){console.log(e.target.value);}}
app.component.html
I will try to show last 12 months with year in select
option dynamically.
Eg:
If current month is
March
and year2021
, I need to showMarch-2021
is first option after last previous 12 months next options in reverse order. If current month isApril
, show first option as 'April-2021'
https://stackblitz.com/edit/angular-ivy-oxoblx?file=src%2Fapp%2Fapp.component.html
Please check bellow image for example
appcomponent.ts
import { Component, VERSION } from '@angular/core';
@Component({
selector: 'my-app',
templateUrl: './app.component.html',
styleUrls: [ './app.component.css' ]
})
export class AppComponent {
name = 'Angular ' + VERSION.major;
months = [{id:'01', name:'Jan'}, {id:'02', name:'Feb'},{id:'03', name:'Mar'},{id:'04', name:'Apr'},{id:'05', name:'May'},{id:'06', name:'Jun'},{id:'07', name:'Jul'},{id:'08', name:'Aug'},{id:'09', name:'Sep'},{id:'10', name:'Oct'},{id:'11', name:'Nav'},{id:'12', name:'Dec'},];
appcomponent.html
<select>
<option *ngFor="let month of months" value="{{month.id}}">{{month.name}}</option>
</select>
<h3>Expected formate</h3>
<select>
<option value="03">Mar-2021</option>
<option value="02">Feb-2021</option>
<option value="01">Jan-2021</option>
<option value="12">Dec-2020</option>
<option value="11">Nav-2020</option>
<option value="10">Oct-2020</option>
<option value="09">Sep-2020</option>
<option value="08">Aug-2020</option>
<option value="07">Jul-2020</option>
<option value="06">Jun-2020</option>
<option value="05">May-2020</option>
<option value="04">Apr-2020</option>
</select>
Please try this. You can easily subtract months from date object one by one and the date object gets updated accordingly as seen below
app.component.ts
import { Component, VERSION } from "@angular/core";
@Component({
selector: "my-app",
templateUrl: "./app.component.html",
styleUrls: ["./app.component.css"]
})
export class AppComponent {
dates = [];
constructor() {
for (var i = 0; i < 12; i++) {
var d = new Date();
d.setMonth(d.getMonth() - i);
var month = d.toLocaleString("default", { month: "long" });
var year = d.getFullYear();
var monthNo=d.getMonth();
if(monthNo<9){
this.dates.push( {month:"0"+(monthNo+1),date:month+"-"+year});
}else{
this.dates.push( {month:(monthNo+1),date:month+"-"+year});
}
}
}
name = "Angular " + VERSION.major;
months = [
{ id: "01", name: "Jan" },
{ id: "02", name: "Feb" },
{ id: "03", name: "Mar" },
{ id: "04", name: "Apr" },
{ id: "05", name: "May" },
{ id: "06", name: "Jun" },
{ id: "07", name: "Jul" },
{ id: "08", name: "Aug" },
{ id: "09", name: "Sep" },
{ id: "10", name: "Oct" },
{ id: "11", name: "Nav" },
{ id: "12", name: "Dec" }
];
selectChange(e) {
console.log(e.target.value);
}
}
app.component.html
<select>
<option *ngFor="let month of months" value="{{month.id}}">{{month.name}}</option>
</select>
<h3>Expected formate</h3>
<select (change)="selectChange($event)">
<option value="{{date.month}}" *ngFor="let date of dates;index as i;">{{date.date}}</option>
</select>
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