Angular PrimeNG表懒加载

Angular PrimeNG是一个开源框架，拥有丰富的原生Angular UI组件，可用于出色的造型，该框架可用于制作响应式网站，非常方便。这篇文章将向我们展示如何在Angular PrimeNG中使用表延迟加载。

Angular PrimeNG Table Lazy Loading是用来懒惰地加载TreeTable组件的数据。它在需要的时候加载数据，使TreeTable更具互动性和用户友好性。

语法:

// In app.component.html
<p-table
    [columns]="cols"
    [value]="tableData"
    [lazy]="true"
    (onLazyLoad)="loadNodes($event)"
    [loading]="loading">
</p-table>

// In app.component.ts 
loadNodes(event) {
    // lazy function
}

创建Angular应用程序和模块安装。

第1步：使用以下命令创建一个Angular应用程序。

ng new appname

第2步：创建你的项目文件夹即appname后，使用以下命令移动到它。

cd appname

第3步在你给定的目录中安装PrimeNG。

npm install primeng --save
npm install primeicons --save

项目结构：它将看起来像如下。

Angular PrimeNG表懒散加载

例子1：下面是一个简单的例子，演示了Angular PrimeNG表懒惰加载的使用。

<h2 style="color: green">GeeksforGeeks</h2>
<h4>Angular PrimeNG Table Lazy Loading</h4>
  
<p-table 
    [value]="tableData" 
    [lazy]="true" 
    (onLazyLoad)="loadNodes($event)" 
    [loading]="loading">
    <ng-template pTemplate="header">
        <tr>
            <th>First Name</th>
            <th>Last Name</th>
            <th>Age</th>
        </tr>
    </ng-template>
  
    <ng-template pTemplate="body" let-people>
        <tr>
            <td>{{ people.firstname }}</td>
            <td>{{ people.lastname }}</td>
            <td>{{ people.age }}</td>
        </tr>
    </ng-template>
</p-table>

import { Component } from '@angular/core';
import { NodeService } from './nodeservice';
  
interface People {
    firstname?: string;
    lastname?: string;
    age?: string;
}
  
@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
})
export class AppComponent {
    tableData: People[] = [];
    cols: any[] = [];
    loading: boolean = false;
    constructor(private nodeService: NodeService) { }
  
    ngOnInit() {
        this.cols = [
            { field: 'firstname', header: 'First Name' },
            { field: 'lastname', header: 'Last Name' },
            { field: 'age', header: 'Age' },
        ];
        this.loading = true;
    }
    loadNodes(event: any) {
        this.loading = true;
        setTimeout(() => {
            this.loading = false;
            this.tableData = [
                {
                    firstname: 'David',
                    lastname: 'ace',
                    age: '40',
                },
                {
                    firstname: 'AJne',
                    lastname: 'west',
                    age: '40',
                },
                {
                    firstname: 'Mak',
                    lastname: 'Lame',
                    age: '40',
                },
                {
                    firstname: 'Peter',
                    lastname: 'raw',
                    age: '40',
                },
                {
                    firstname: 'Kane',
                    lastname: 'James',
                    age: '40',
                },
            ];
        }, 1000);
    }
}

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';
import { BrowserAnimationsModule } 
    from '@angular/platform-browser/animations';
import { RouterModule } from '@angular/router';
  
import { AppComponent } from './app.component';
import { NodeService } from './nodeservice';
  
import { TreeTableModule } from 'primeng/treetable';
import { ButtonModule } from 'primeng/button';
import { DialogModule } from 'primeng/dialog';
import { MultiSelectModule } from 'primeng/multiselect';
import { InputTextModule } from 'primeng/inputtext';
import { ToastModule } from 'primeng/toast';
import { ContextMenuModule } from 'primeng/contextmenu';
import { TableModule } from 'primeng/table';
  
@NgModule({
    imports: [
        BrowserModule,
        BrowserAnimationsModule,
        TreeTableModule,
        ToastModule,
        TableModule,
        DialogModule,
        ButtonModule,
        MultiSelectModule,
        InputTextModule,
        ContextMenuModule,
        HttpClientModule,
        FormsModule,
        RouterModule.forRoot([{ path: '', component: AppComponent }]),
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [NodeService],
})
export class AppModule { }

输出:

Angular PrimeNG表懒散加载

例子2：下面是另一个例子，演示Angular PrimeNG表懒惰加载的使用。在这个例子中，我们懒惰地加载了5秒钟的数据。

<h2 style="color: green">GeeksforGeeks</h2>
<h4>Angular PrimeNG Table Lazy Loading</h4>
  
<p-table 
    [value]="tableData" 
    [lazy]="true" 
    (onLazyLoad)="loadNodes($event)" 
    [loading]="loading">
    <ng-template pTemplate="header">
        <tr>
            <th>First Name</th>
            <th>Last Name</th>
            <th>Age</th>
        </tr>
    </ng-template>
  
    <ng-template pTemplate="body" let-people>
        <tr>
            <td>{{ people.firstname }}</td>
            <td>{{ people.lastname }}</td>
            <td>{{ people.age }}</td>
        </tr>
    </ng-template>
</p-table>

import { Component, OnInit } from '@angular/core';
import { NodeService } from './nodeservice';
  
interface People {
    firstname?: string;
    lastname?: string;
    age?: string;
}
  
@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
})
export class AppComponent {
    tableData: People[] = [];
    cols: any[] = [];
    loading: boolean = false;
    constructor(private nodeService: NodeService) { }
  
    ngOnInit() {
        this.cols = [
            { field: 'firstname', header: 'First Name' },
            { field: 'lastname', header: 'Last Name' },
            { field: 'age', header: 'Age' },
        ];
        this.loading = true;
    }
    loadNodes(event: any) {
        this.loading = true;
        setTimeout(() => {
            this.loading = false;
            this.tableData = [
                {
                    firstname: 'David',
                    lastname: 'ace',
                    age: '40',
                },
                {
                    firstname: 'AJne',
                    lastname: 'west',
                    age: '40',
                },
                {
                    firstname: 'Mak',
                    lastname: 'Lame',
                    age: '40',
                },
                {
                    firstname: 'Peter',
                    lastname: 'raw',
                    age: '40',
                },
                {
                    firstname: 'Kane',
                    lastname: 'James',
                    age: '40',
                },
            ];
        }, 5000);
    }
}

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';
import { BrowserAnimationsModule } 
    from '@angular/platform-browser/animations';
import { RouterModule } from '@angular/router';
  
import { AppComponent } from './app.component';
import { NodeService } from './nodeservice';
  
import { TreeTableModule } from 'primeng/treetable';
import { ButtonModule } from 'primeng/button';
import { DialogModule } from 'primeng/dialog';
import { MultiSelectModule } from 'primeng/multiselect';
import { InputTextModule } from 'primeng/inputtext';
import { ToastModule } from 'primeng/toast';
import { ContextMenuModule } from 'primeng/contextmenu';
import { TableModule } from 'primeng/table';
  
@NgModule({
    imports: [
        BrowserModule,
        BrowserAnimationsModule,
        TreeTableModule,
        ToastModule,
        TableModule,
        DialogModule,
        ButtonModule,
        MultiSelectModule,
        InputTextModule,
        ContextMenuModule,
        HttpClientModule,
        FormsModule,
        RouterModule.forRoot([{ path: '', component: AppComponent }]),
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [NodeService],
})
export class AppModule { }