Question

迫切需要回答。我正在尝试检索下面附带的快照中标记的单个学校名称，并从我的firebase-database

填充到我的android spinner

connectedCallback() { 
  super.connectedCallback();
  this.addEventListener('custom-event', () => { console.log('a');});
}

Answer 1

所以我想回答我的问题..我在@Alex Mamo视频的帮助下工作了

所以一切都保持不变......我所做的就是调整我的代码

而不是

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace DM_Config_Tool
{
    public partial class Form_FW_Upload : Form
    {
        int form_Height1 = 379;
        int form_Width = 276;
        int form_Height2 = 419;
        string RX_DATA = null;
        Timer Timer = new Timer();
        Program Program = new Program();

        public Form_FW_Upload()
        {
            InitializeComponent();
        }

        private void Form_FW_Upload_Load(object sender, EventArgs e)
        {


            Timer.Interval = 1000;
            Timer.Enabled = true;
            this.Height = form_Height1;
            button2.Enabled = false;
            button3.Enabled = false;
            //Timer.Start();
            //Timer.Tick += new EventHandler(timer_tick);
        }
        private void timer_tick(object sender, EventArgs e)
        {
            RX_DATA = Program.Serial_Receive_Data();
            if(RX_DATA != null)
            {
                Timer.Stop();
                textBox3.Text = RX_DATA;
            }
        }

        private void Form_FW_Upload_FormClosed(object sender, FormClosedEventArgs e)
        {
            Form_Connect form_Connect = new Form_Connect();
            this.Hide();

            //form_Connect.Show();
            Application.Exit();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.Height = form_Height2;
            Program.Serial_Connect("COM4");
            Program.Serial_Send_Cmd("BLM\n\r",false);

        }

        private void button1_Click(object sender, EventArgs e)
        {
            button2.Enabled = true;
        }
    }
}

相反，我做了

fireBaseConnection.reg_schools.child(key).child("school_name").addValueEventListener(){
    //Then my codes here
}

所以基本上我用快照来引用我在onDataChange方法中寻找的节点“school_name”

Android从FireBase-RealTime数据库中检索单值

1 个答案: