极客教程Angular PrimeNG TreeTable 懒加载
Angular PrimeNG是一个开源框架，拥有丰富的原生Angular UI组件，可用于出色的风格设计，该框架可用于制作响应式网站，非常方便。本文将向我们展示如何在Angular PrimeNG中使用树表懒惰加载。
Angular PrimeNG TreeTable 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-treeTable
[columns]="cols"
[value]="tableData"
**[lazy]="true"**
**(onLazyLoad)="loadNodes($event)"**
[loading]="loading">
...
</p-treeTable>
// In app.component.ts
loadNodes(event) {
// lazy function
}
创建Angular应用程序和模块安装。
第1步：使用以下命令创建一个Angular应用程序。
ng new appname
第2步：创建你的项目文件夹即appname后，使用以下命令移动到它。
cd appname
步骤3：在你给定的目录中安装PrimeNG。
npm install primeng --save
npm install primeicons --save
项目结构：它将看起来像如下。
Project Structure
例子1：下面是一个简单的例子，演示Angular PrimeNG TreeTable Lazy Loading的使用。
<h2 style="color: green">GeeksforGeeks</h2>
<h4>Angular PrimeNG TreeTable Lazy Loading</h4>
<p-treeTable
[columns]="cols"
[value]="tableData"
[lazy]="true"
(onLazyLoad)="loadNodes($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-rowNode
let-rowData="rowData">
<tr>
<td>
<p-treeTableToggler
[rowNode]="rowNode">
</p-treeTableToggler>
{{ rowData.firstname }}
</td>
<td>{{ rowData.lastname }}</td>
<td>{{ rowData.age }}</td>
</tr>
</ng-template>
</p-treeTable>
import { Component, OnInit } from '@angular/core';
import { NodeService } from './nodeservice';
import { TreeNode } from 'primeng/api';
@Component({
selector: 'app-root',
templateUrl: './app.component.html'
})
export class AppComponent {
tableData: TreeNode[] = [];
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.tableData = [
{
data: {
firstname: 'David',
lastname: 'ace',
age: '40',
},
children: [
{
data: {
firstname: 'Nathan',
lastname: 'ace',
age: '16',
},
children: [
{
data: {
firstname: 'Abe',
lastname: 'ace',
age: '12',
},
},
{
data: {
firstname: 'Ksi',
lastname: 'ace',
age: '12',
},
},
],
},
{
data: {
firstname: 'Shane',
lastname: 'ace',
age: '14',
},
},
],
},
{
data: {
firstname: 'Warner',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
lastname: 'ace',
firstname: 'Michelle',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'Max',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'Willy',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'Miley',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'Sam',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'James',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
lastname: 'ace',
firstname: 'Charlie',
age: '24',
},
},
],
},
];
this.loading = false;
}, 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 { AppComponent } from './app.component';
import { NodeService } from './nodeservice';
import { TreeTableModule } from 'primeng/treetable';
import { ButtonModule } from 'primeng/button';
import { InputTextModule } from 'primeng/inputtext';
@NgModule({
imports: [
BrowserModule,
BrowserAnimationsModule,
TreeTableModule,
ButtonModule,
InputTextModule,
HttpClientModule,
FormsModule,
],
declarations: [AppComponent],
bootstrap: [AppComponent],
providers: [NodeService],
})
export class AppModule { }
输出:
实例2：下面是另一个演示Angular PrimeNG TreeTable Lazy Loading的例子。在这个例子中，我们懒惰地加载了5秒钟的数据。
app.component.ts
<h2 style="color: green">GeeksforGeeks</h2>
<h4>Angular PrimeNG TreeTable Lazy Loading</h4>
<p-treeTable
[columns]="cols"
[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-rowNode
let-rowData="rowData">
<tr>
<td>
<p-treeTableToggler
[rowNode]="rowNode">
</p-treeTableToggler>
{{ rowData.firstname }}
</td>
<td>{{ rowData.lastname }}</td>
<td>{{ rowData.age }}</td>
</tr>
</ng-template>
</p-treeTable>
import { Component, OnInit } from '@angular/core';
import { NodeService } from './nodeservice';
import { TreeNode } from 'primeng/api';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
})
export class AppComponent {
tableData: TreeNode[] = [];
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.tableData = [
{
data: {
firstname: 'David',
lastname: 'ace',
age: '40',
},
children: [
{
data: {
firstname: 'Nathan',
lastname: 'ace',
age: '16',
},
children: [
{
data: {
firstname: 'Abe',
lastname: 'ace',
age: '12',
},
},
{
data: {
firstname: 'Ksi',
lastname: 'ace',
age: '12',
},
},
],
},
{
data: {
firstname: 'Shane',
lastname: 'ace',
age: '14',
},
},
],
},
{
data: {
firstname: 'Warner',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
lastname: 'ace',
firstname: 'Michelle',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'Max',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'Willy',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'Miley',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'Sam',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
firstname: 'Charlie',
lastname: 'ace',
age: '24',
},
},
],
},
{
data: {
firstname: 'James',
lastname: 'ace',
age: '55',
},
children: [
{
data: {
firstname: 'Michelle',
lastname: 'ace',
age: '20',
},
},
{
data: {
lastname: 'ace',
firstname: 'Charlie',
age: '24',
},
},
],
},
];
this.loading = false;
}, 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 { AppComponent } from './app.component';
import { NodeService } from './nodeservice';
import { TreeTableModule } from 'primeng/treetable';
import { ButtonModule } from 'primeng/button';
import { InputTextModule } from 'primeng/inputtext';
@NgModule({
imports: [
BrowserModule,
BrowserAnimationsModule,
TreeTableModule,
ButtonModule,
InputTextModule,
HttpClientModule,
FormsModule,
],
declarations: [AppComponent],
bootstrap: [AppComponent],
providers: [NodeService],
})
export class AppModule { }
输出:
