Angular material 如何使用自定义管道在angular中的“自动完成”下拉列表中对（asc顺序）数据（来自数据库）进行排序

app.component.html

{{option.name}

应用程序组件.ts

1. import { SortPipe } from "../../../pipes/sort.pipe";
2. private sortPipe: SortPipe,

1. import { SortPipe } from '../../pipes/sort.pipe';
2.@NgModule({
  declarations: [
        SortPipe
  ], 
   providers: [SortPipe]

import { Injectable, Pipe, PipeTransform } from '@angular/core';
export type SortOrder = 'asc' | 'desc';

@Injectable()
@Pipe({
  name: 'sort',
})
export class SortPipe implements PipeTransform {
  transform(value: any, sortOrder: SortOrder | string = 'asc', sortKey?: string): any {
    sortOrder = sortOrder && (sortOrder.toLowerCase() as any);

    if (!value || (sortOrder !== 'asc' && sortOrder !== 'desc')) return value;

    let numberArray = [];
    let stringArray = [];

    if (!sortKey) {
      numberArray = value.filter(item => typeof item === 'number').sort();
      stringArray = value.filter(item => typeof item === 'string').sort();
    } else {
      numberArray = value.filter(item => typeof item[sortKey] === 'number').sort((a, b) => a[sortKey] - b[sortKey]);
      stringArray = value
        .filter(item => typeof item[sortKey] === 'string')
        .sort((a, b) => {
          if (a[sortKey] < b[sortKey]) return -1;
          else if (a[sortKey] > b[sortKey]) return 1;
          else return 0;
        });
    }
    const sorted = numberArray.concat(stringArray);
    return sortOrder === 'asc' ? sorted : sorted.reverse();
  }
}

应用程序模块.ts

1. import { SortPipe } from "../../../pipes/sort.pipe";
2. private sortPipe: SortPipe,

1. import { SortPipe } from '../../pipes/sort.pipe';
2.@NgModule({
  declarations: [
        SortPipe
  ], 
   providers: [SortPipe]

import { Injectable, Pipe, PipeTransform } from '@angular/core';
export type SortOrder = 'asc' | 'desc';

@Injectable()
@Pipe({
  name: 'sort',
})
export class SortPipe implements PipeTransform {
  transform(value: any, sortOrder: SortOrder | string = 'asc', sortKey?: string): any {
    sortOrder = sortOrder && (sortOrder.toLowerCase() as any);

    if (!value || (sortOrder !== 'asc' && sortOrder !== 'desc')) return value;

    let numberArray = [];
    let stringArray = [];

    if (!sortKey) {
      numberArray = value.filter(item => typeof item === 'number').sort();
      stringArray = value.filter(item => typeof item === 'string').sort();
    } else {
      numberArray = value.filter(item => typeof item[sortKey] === 'number').sort((a, b) => a[sortKey] - b[sortKey]);
      stringArray = value
        .filter(item => typeof item[sortKey] === 'string')
        .sort((a, b) => {
          if (a[sortKey] < b[sortKey]) return -1;
          else if (a[sortKey] > b[sortKey]) return 1;
          else return 0;
        });
    }
    const sorted = numberArray.concat(stringArray);
    return sortOrder === 'asc' ? sorted : sorted.reverse();
  }
}

定制管道

共享-->管道-->排序.pipe.ts

1. import { SortPipe } from "../../../pipes/sort.pipe";
2. private sortPipe: SortPipe,

1. import { SortPipe } from '../../pipes/sort.pipe';
2.@NgModule({
  declarations: [
        SortPipe
  ], 
   providers: [SortPipe]

import { Injectable, Pipe, PipeTransform } from '@angular/core';
export type SortOrder = 'asc' | 'desc';

@Injectable()
@Pipe({
  name: 'sort',
})
export class SortPipe implements PipeTransform {
  transform(value: any, sortOrder: SortOrder | string = 'asc', sortKey?: string): any {
    sortOrder = sortOrder && (sortOrder.toLowerCase() as any);

    if (!value || (sortOrder !== 'asc' && sortOrder !== 'desc')) return value;

    let numberArray = [];
    let stringArray = [];

    if (!sortKey) {
      numberArray = value.filter(item => typeof item === 'number').sort();
      stringArray = value.filter(item => typeof item === 'string').sort();
    } else {
      numberArray = value.filter(item => typeof item[sortKey] === 'number').sort((a, b) => a[sortKey] - b[sortKey]);
      stringArray = value
        .filter(item => typeof item[sortKey] === 'string')
        .sort((a, b) => {
          if (a[sortKey] < b[sortKey]) return -1;
          else if (a[sortKey] > b[sortKey]) return 1;
          else return 0;
        });
    }
    const sorted = numberArray.concat(stringArray);
    return sortOrder === 'asc' ? sorted : sorted.reverse();
  }
}

从'@angular/core'导入{Injectable，Pipe，PipeTransform}；
导出类型排序器='asc'|'desc'；
@可注射（）
@烟斗({
名称：'排序'，
})
导出类SortPipe实现PipeTransform{
转换（值：any，sortOrder:sortOrder | string='asc'，sortKey？：string）：any{
sortOrder=sortOrder&（sortOrder.toLowerCase（）如有）；
if（！value | |（sortOrder！='asc'&&sortOrder！=='desc'））返回值；
设numberArray=[]；
设stringArray=[]；
if（！sortKey）{
numberArray=value.filter（item=>typeof item=='number'）.sort（）；
stringArray=value.filter（item=>typeof item==='string'）.sort（）；
}否则{
numberArray=value.filter（item=>typeof item[sortKey]==“number”）.sort（（a，b）=>a[sortKey]-b[sortKey]）；
stringArray=值
.filter（项=>typeof项[sortKey]==“string”）
.排序（（a，b）=>{
if（a[sortKey]b[sortKey]）返回1；
否则返回0；
});
}
const sorted=numberArray.concat（字符串数组）；
return sortOrder=='asc'？排序：sorted.reverse（）；
}
}

---

问题：它不按升序显示。有什么我没有输入的吗？

请为具有方向的

排序管道提供适当的参数，并在app.component.html中为其应用排序的字段名，如下所示：

<mat-option *ngFor="let option of filteredOptions| async | sort: 'asc':'name'" [value]="option"> {{option.name}}

{{option.name}

请参考以下示例：