如何在角度中将搜索过滤器添加到选择选项 [英] How to add a search filter to a select option in angular

问题描述

我试图在我的选择选项列表中添加搜索过滤器，因为有很多选项，而且我认为如果没有搜索，用户将很难找到他想要选择的选项.

I'm trying to add to add a search filter in my select option list because there are many options and I think that without a search, it will not be easy for the user to find the option that he wants to select.

我希望你能理解我，因为我不会英语.

I hope you will understand me because I'm not good at English.

这是我的代码(这只是表的一部分)

Here's my code (it's just a part of my table)

<ng-container *ngFor="let menaceProcessus of menaceProcessusTab">
    <tr>
         <td colspan="4" bgcolor="#f1f1f1"><b>{{menaceProcessus?.processus?.nom}}</b></td>
    </tr>
    <ng-container *ngFor="let actif of menaceProcessus?.actifs">
        <tr>
            <td [rowSpan]="actif?.menaces?.length+1">{{actif?.actif?.nom}}</td>
        </tr>
     <ng-container *ngFor="let mnVuln of actif?.menaces">
        <tr>
             <td>{{mnVuln?.vulnerabilite?.nom}}</td>
             <td>
                 <select class="form-control" 
                  (change)="mnVuln?.menaceActif?.menace.id = $event.target.value; 
                            updateMenaceProcessus()">
                      <option></option>
                      <option *ngFor="let menace of menaces" 
                          [value]="menace.id" 
                          [selected]="menace.id === mnVuln?.menaceActif?.menace.id">
                        {{menace.nom}}</option>
                  </select>
              </td>
              <td>
                 <input class="form-control" 
                    type="text" [value]="mnVuln?.menaceActif?.probabilite"> 
              </td>
          </tr>
      </ng-container>
    </ng-container>
 </ng-container>

推荐答案

如果要通过在第一个字母上键入来过滤数组威胁，则可以像这样过滤数组:

If you want to filter your array menaces by typing on the first letter, then it is possible to filter your array like this:

HTML:

<select class="form-control" 
     (change)="mnVuln?.menaceActif?.menace.id = $event.target.value; 
               updateMenaceProcessus();
               filterMenaces($event)">
    <option></option>
    <option *ngFor="let menace of menaces" 
        [value]="menace.id" 
        [selected]="menace.id === mnVuln?.menaceActif?.menace.id">
        {{menace.nom}}</option>
</select>

TypeScript:

TypeScript:

origMenaces = [];

methodAPIToGetMenaces() {
   this.yourService()
       .subscribe(s=> {
           this.menaces = s;
           this.origMenaces = s;
       });
}

filterMenaces(str: string) {
    if (typeof str === 'string') {
        this.menaces = this.origMenaces.filter(a => a.toLowerCase()
                                             .startsWith(str.toLowerCase())); 
    }
}

更新1:

如果要按 input 值进行过滤:

HTML:

<input type="text"         
    (ngModelChange)="filterItem($event)" 
    [(ngModel)]="filterText">
    <br>
<select 
     #selectList
     [(ngModel)]="myDropDown" 
    (ngModelChange)="onChangeofOptions($event)">
    <option value="empty"></option>
    <option *ngFor="let item of items">         
        {{item}}
    </option>    
</select>
<p>items {{ items | json }}</p>

TypeScript:

TypeScript:

import { Component, ViewChild, ElementRef, AfterViewInit } from '@angular/core';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  name = 'Angular 4';
  myDropDown : string;
  items = ['one', 'two', 'three'];
  origItems = ['one', 'two', 'three'];
  @ViewChild('selectList', { static: false }) selectList: ElementRef;

  onChangeofOptions(newGov) {
     console.log(newGov);
  }

  filterItem(event){
      if(!event){
          this.items = this.origItems;
      } // when nothing has typed*/   
      if (typeof event === 'string') {
          console.log(event);
          this.items = this.origItems.filter(a => a.toLowerCase()
                                             .startsWith(event.toLowerCase())); 
      }
      console.log(this.items.length);
      this.selectList.nativeElement.size = this.items.length + 1 ;       
   }      
}

请在stackblitz上查看工作示例

这篇关于如何在角度中将搜索过滤器添加到选择选项的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！