小编fer*_*lde的帖子

我的方法从Firebase返回一个Observable数组.我决定过滤客户端而不是服务器中的数据.我的问题是,如果属性"atte = true",我只想获取数据.任何帮助或其他方法都非常感谢.非常感谢你.

下面的方法从firebase实时数据库中获取数据

userEvents: Observable<any[]>;

getUserEvents(uid: string) {
this.userEvents = this.db.list(this.basePatheventsSaved, ref=> 
 ref.orderByChild('uid').equalTo(uid)).snapshotChanges().map((actions) => {
  return actions.map((a) => {
    const data = a.payload.val();
    const $key = a.payload.key;
    return { $key, ...data };
  });
});
return this.userEvents;
} 

下面的代码用于确定templaTe中使用的数据:

 userEvents: Observable<any[]>;
 constructor(public auth: AuthService, private upSvc: FilesServiceService) { 
this.userEvents = this.upSvc.getUserEvents(this.auth.currentUserId);
 }

我的目标是确保用户在提交表单之前输入有效数据（无数字）并且输入字段不应为空。帮助！！！

ts文件代码如下：

import { Routes, RouterModule, Router, ActivatedRoute } from "@angular/router";
import { Component, NgModule, Input, Output, EventEmitter } from '@angular/core';
import { Environments } from './Environment-class';
import { FormBuilder, FormsModule, ReactiveFormsModule, FormGroup, FormControl, Validators } from '@angular/forms';

@Component({
selector: 'addenvironment-form',
templateUrl: './add-environment-form.component.html'
  })
 export class AddEnvironmentComponent {

@Output() EnvironementCreated = new EventEmitter<Environments>();
createNewEnv(EnvironmentNames: string) {
    this.EnvironementCreated.emit(new Environments(EnvironmentNames));
}

}

和 HTML 文件

<br />
<div class="card">
<h4 class="card-header">Add a New Environment</h4>
<div class="card-body mx-auto  ">
    <form class="form-inline ">
        <div …

我正在创建一个存储到arraylist(项目键,数量和项目的价格)的篮子.如何仅更新数量而不是使用相同的Item键创建另一行.以下是该程序的结果.

Java Book                 1   £48.90

Samsung Galaxy S7         1   £639.50


Speakers                  3   £59.80


Java Book                 2   £48.90


Samsung Galaxy S7         2   £639.50

//////////////////////////////////////////////////

private void ItemsBasket(String name, int qty, String key) throws HeadlessException {

        if (name == null) {
            JOptionPane.showMessageDialog(null, "Please Selecet a key");
            String imageFileName = "./images/" + key + ".png";
            File imageFile = new File(imageFileName);

            if (!imageFile.exists()) {
                imageFileName = "./images/empty.png";
            }

        } else if (qty <= StockData.getQuantity(key)) {


            arList.add(StockData.getName(key) + "\t\t  " + qty + "   " …