Javascript 为什么此角度材质表不渲染？

我正在使用Angular 9和Angular材质制作一个Contacts应用程序。对于每个联系人，列表组件应在表行中显示一些信息和图像

在我的

app.module.ts

中，我导入了

MatTableModule

在

app\services\contacts list.service.ts

中，我有：

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { map } from 'rxjs/operators';

import { Contact } from '../models/Contact';

const httpOptions = {
  headers: new HttpHeaders({
    'Content-Type': 'application/json'
  })
}

@Injectable({
  providedIn: 'root'
})

export class ContactsListService {

  contactsUrl = 'https://randomuser.me/api/?&results=20&inc=name,location,email,cell,picture';

  constructor(private http:HttpClient) { }

  getContcts():Observable<Contact[]> {
    return this.http.get<Contact[]>(`${this.contactsUrl}`)
      .pipe(map(response => response['results']));
  }

  getOneContact():Observable<Contact[]> {
    return this.http.get<Contact[]>(`${this.contactsUrl}`)
      .pipe(map(response => response['results']));
  }

}

import { Component, OnInit } from '@angular/core';
import { MatTableDataSource } from '@angular/material/table';
import { from } from 'rxjs';
import { ContactsListService } from '../../services/contacts-list.service';
import { Contact } from '../../models/Contact';

@Component({
  selector: 'app-list',
  templateUrl: './list.component.html',
})

export class ListComponent implements OnInit {

  pageTitle = 'My Contacts';

  contactsList:Contact[];

  constructor(private ContactsListService:ContactsListService) { }

  contactsTableData: MatTableDataSource<any>;
  displayedColumns: string[] = ['fullName', 'photo', 'email', 'city', 'country'];

  ngOnInit(): void  {
    // Contact list
    this.ContactsListService.getContcts().subscribe(
      contactsList => { 
        this.contactsList = contactsList; console.log(contactsList);
        this.contactsTableData = new MatTableDataSource(contactsList);
      },
      error => { }
    );
  }
}

I上述组件的模板：

<div class="container">
    <h2 class="mat-display-1 page-title">{{pageTitle}}</h2>
    <div class="mat-elevation-z8">
        <mat-table [data-source]="contactsTableData">

            <ng-container matColumnDef="fullName">
                <mat-header-cell *matHeaderCellDef> Full Name </mat-header-cell>
                <mat-cell *matCellDef="let element"> {{element.name.first}} {{element.name.last}} </mat-cell>
            </ng-container>

            <ng-container matColumnDef="photo">
                <mat-header-cell *matHeaderCellDef> Photo </mat-header-cell>
                <mat-cell *matCellDef="let element"> {{element.picture.large}} </mat-cell>
            </ng-container>

            <ng-container matColumnDef="email">
                <mat-header-cell *matHeaderCellDef> Email address </mat-header-cell>
                <mat-cell *matCellDef="let element"> {{element.email}} </mat-cell>
            </ng-container>

            <ng-container matColumnDef="city">
                <mat-header-cell *matHeaderCellDef> City </mat-header-cell>
                <mat-cell *matCellDef="let element"> {{element.location.city}} </mat-cell>
            </ng-container>

            <ng-container matColumnDef="phone">
                <mat-header-cell *matHeaderCellDef> Phone </mat-header-cell>
                <mat-cell *matCellDef="let element"> {{element.cell}} </mat-cell>
            </ng-container>

            <ng-container matColumnDef="country">
                <mat-header-cell *matHeaderCellDef> Country </mat-header-cell>
                <mat-cell *matCellDef="let element"> {{element.location.country}} </mat-cell>
            </ng-container>

            <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row>
            <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>
        </mat-table>
    </div>
</div>

---

缺少什么？

在卫生棉条上，

垫表

应使用

[dataSource]

而不是

[dataSource]

。这会解决你的问题

---

另外，快速提示，您的响应不会返回一个

ContactAM

数组，而是返回一个名为

results

的属性的对象，该属性的值为

ContactAM

数组。因此，在您的

服务上

，您执行

HTTP GET呼叫

并将其键入

ContactAM[]

，您应该实际将其键入

{results:ContactAM[]}

以下是问题的解决方法，以防其他人使用此信息：

在

app\components\list\list.component.ts

文件中，我有：

import { Component, OnInit, ViewChild } from '@angular/core';
import { MatTableDataSource } from '@angular/material/table';
import { MatPaginator } from '@angular/material/paginator';
import { from } from 'rxjs';
import { ContactsListService } from '../../services/contacts-list.service';
import { Contact } from '../../models/Contact';

@Component({
  selector: 'app-list',
  templateUrl: './list.component.html',
})

export class ListComponent implements OnInit {

  pageTitle = 'My Contacts';

  contactsList:Contact[];

  constructor(private ContactsListService:ContactsListService) { }

  contactsTableData: MatTableDataSource<any>;
  displayedColumns: string[] = ['fullName', 'photo', 'email', 'phone', 'city', 'country'];

  @ViewChild(MatPaginator) paginator: MatPaginator;

  ngOnInit(): void  {
    // Contact list
    this.ContactsListService.getContcts().subscribe(
      contactsList => { 
        this.contactsList = contactsList;
        this.contactsTableData = new MatTableDataSource(contactsList);
        this.contactsTableData.paginator = this.paginator;
      },
      error => { }
    );
  }
}

---

似乎使用了

，而不是

？（编辑：不考虑我的猜测，他们也使用

th mat header单元格

，但你说你的header代码确实有效）文档似乎也使用

数据源

，而不是

数据源

。你可以试着改变它。@AkashBhardwaj这确实是个问题。是的，我在看一本旧的（er）教程。谢谢

import { Component, OnInit, ViewChild } from '@angular/core';
import { MatTableDataSource } from '@angular/material/table';
import { MatPaginator } from '@angular/material/paginator';
import { from } from 'rxjs';
import { ContactsListService } from '../../services/contacts-list.service';
import { Contact } from '../../models/Contact';

@Component({
  selector: 'app-list',
  templateUrl: './list.component.html',
})

export class ListComponent implements OnInit {

  pageTitle = 'My Contacts';

  contactsList:Contact[];

  constructor(private ContactsListService:ContactsListService) { }

  contactsTableData: MatTableDataSource<any>;
  displayedColumns: string[] = ['fullName', 'photo', 'email', 'phone', 'city', 'country'];

  @ViewChild(MatPaginator) paginator: MatPaginator;

  ngOnInit(): void  {
    // Contact list
    this.ContactsListService.getContcts().subscribe(
      contactsList => { 
        this.contactsList = contactsList;
        this.contactsTableData = new MatTableDataSource(contactsList);
        this.contactsTableData.paginator = this.paginator;
      },
      error => { }
    );
  }
}

<div class="container">
    <div class="mat-elevation-z8">
        <table mat-table [dataSource]="contactsTableData" class="w-100">
            <ng-container matColumnDef="fullName">
                <th mat-header-cell *matHeaderCellDef>Full Name</th>
                <td mat-cell *matCellDef="let element">{{element.name.first}} {{element.name.last}}</td>
            </ng-container>

            <ng-container matColumnDef="photo">
                <th mat-header-cell *matHeaderCellDef>Photo</th>
                <td mat-cell *matCellDef="let element">
                    <img src="{{element.picture.large}}" alt="{{element.name.first}} {{element.name.last}}" class="thumbnail rounded-circle">
                </td>
            </ng-container>

            <ng-container matColumnDef="email">
                <th mat-header-cell *matHeaderCellDef>Email address</th>
                <td mat-cell *matCellDef="let element">
                    <a href="mailto:{{element.email}}">{{element.email}}</a>
                </td>
            </ng-container>

            <ng-container matColumnDef="phone">
                <th mat-header-cell *matHeaderCellDef>Phone</th>
                <td mat-cell *matCellDef="let element">
                    <a href="tel:{{element.phone}}">{{element.cell}}</a>
                </td>
            </ng-container>

            <ng-container matColumnDef="city">
                <th mat-header-cell *matHeaderCellDef>City</th>
                <td mat-cell *matCellDef="let element">{{element.location.city}}</td>
            </ng-container>

            <ng-container matColumnDef="country">
                <th mat-header-cell *matHeaderCellDef>Country</th>
                <td mat-cell *matCellDef="let element">{{element.location.country}}</td>
            </ng-container>

            <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
            <tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
        </table>
        <mat-paginator [pageSizeOptions]="[10, 20, 50]" [pageSize]="10" showFirstLastButtons></mat-paginator>
    </div>
</div>

.rounded-circle {
    border-radius: 50%!important;
}

.thumbnail {
    padding: 2px;
    line-height: 1;
    background-color: #fff;
    border: 1px solid #ddd;
    height: 40px;
    width: auto;
}