tcpipSocket/Chat/Client/ChatRoomForm.cs

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

namespace Client
{
	public partial class ChatRoomForm : Form
	{
		public ChatRoomForm()
		{
			InitializeComponent();
			InitInstance();
		}

		private void InitInstance()
		{
			lbxUser.Items.Add(Singleton.Instance.Nickname);
			Singleton.Instance.UserEnterResponsed += UserEnterResponsed;
			Singleton.Instance.UserLeaveResponsed += UserLeaveResponsed;
		}

		private void btmSend_Click(object sender, EventArgs e)
		{
			if (string.IsNullOrEmpty(tbxMsg.Text))
				return;

			lbxMsg.Items.Add(tbxMsg.Text);
			tbxMsg.Text = null;

			ScrollMsgToEnd();
		}

		private void ScrollMsgToEnd()
		{
			lbxMsg.SelectedIndex = lbxMsg.Items.Count - 1;
			lbxMsg.SelectedIndex = -1;
		}

		private void InvokeMethod(InvokedMethod method)
		{
			if (this.InvokeRequired)
			{
				this.Invoke(new MethodInvoker(() =>
				{
					method();
				}));
			}
			else
			{
				method();
			}
		}

		private void UserEnterResponsed(object? sender, EventArgs e)
		{
			if (sender == null)
				return;

			UserEnterPacket packet = (UserEnterPacket)sender;
			InvokeMethod(() =>
			{
				lbxUser.Items.Add(packet.Nickname);
			});
		}

		private void UserLeaveResponsed(object? sender, EventArgs e)
		{
			if (sender == null)
				return;

			UserLeavePacket packet = (UserLeavePacket)sender;
			InvokeMethod(() =>
			{
				lbxUser.Items.Remove(packet.Nickname);
			});
		}

		private async void ChatRoomForm_FormClosing(object sender, FormClosingEventArgs e)
		{
			Singleton.Instance.UserEnterResponsed -= UserEnterResponsed;
			Singleton.Instance.UserLeaveResponsed -= UserLeaveResponsed;
			
			UserLeavePacket packet = new UserLeavePacket(Singleton.Instance.Nickname);
			await Singleton.Instance.SendAsync(packet.Serialize(), SocketFlags.None);
		}
	}
}