【C#】TcpClientでクライアントの通信処理を作成

using System.Net.Sockets;

public async Task<string> StartClient(string ipaddress, int port, string request)
{
    var buffer = new byte[1024];
    var response = "";

    // サーバーへ接続
    try
    {
        // クライアント作成
        using (var tcpclient = new TcpClient())
        {
            // 送受信タイムアウト設定
            tcpclient.SendTimeout = 1000;
            tcpclient.ReceiveTimeout = 1000;

            // サーバーへ接続開始
            await tcpclient.ConnectAsync(ipaddress, port);
            Debug.WriteLine("サーバーと通信確立");
            using (var stream = tcpclient.GetStream())
            {
                // サーバーへリクエストを送信
                buffer = System.Text.Encoding.ASCII.GetBytes(request);
                await stream.WriteAsync(buffer);
                Debug.WriteLine($"サーバーへ[{request}]を送信");

                // サーバーからレスポンスを受信
                var length = await stream.ReadAsync(buffer, 0, buffer.Length);
                response = System.Text.Encoding.ASCII.GetString(buffer, 0, length);
                Debug.WriteLine($"サーバーから[{response}]を受信");
            }
        }
    }
    catch (Exception ex)
    {
        Debug.WriteLine(ex.ToString());
    }

    return response;
}

<Window
    x:Class="TcpClinet.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Title="TCP/IP (Server)"
    Width="500"
    Height="370"
    WindowStyle="None"
    mc:Ignorable="d">
    <Grid>
        <!--  ヘッダー  -->
        <materialDesign:ColorZone
            Height="50"
            Padding="12"
            Mode="PrimaryMid">
            <DockPanel>
                <materialDesign:PopupBox DockPanel.Dock="Right" PlacementMode="BottomAndAlignRightEdges">
                    <ListBox>
                        <ListBoxItem Content="Close" />
                    </ListBox>
                </materialDesign:PopupBox>
                <StackPanel Orientation="Horizontal">
                    <materialDesign:PackIcon
                        Width="26"
                        Height="26"
                        Kind="AccessPoint" />
                    <TextBlock
                        Margin="16,0,0,0"
                        VerticalAlignment="Center"
                        Text="TCP/IP SAMPLE" />
                </StackPanel>
            </DockPanel>
        </materialDesign:ColorZone>

        <Label
            Margin="15,61,0,0"
            HorizontalAlignment="Left"
            VerticalAlignment="Top"
            Content="TCP/IP通信のクライアント側のサンプル画面です。" />

        <!--  IPアドレス入力欄  -->
        <Label
            x:Name="lblIpaddress"
            Margin="15,99,0,0"
            HorizontalAlignment="Left"
            VerticalAlignment="Top"
            Content="IP アドレス：" />
        <TextBox
            x:Name="txtIpaddress"
            Width="280"
            Margin="90,86,0,0"
            HorizontalAlignment="Left"
            VerticalAlignment="Top"
            materialDesign:HintAssist.Hint="IPアドレスを入力してください。"
            Style="{StaticResource MaterialDesignFloatingHintTextBox}" />

        <!--  ポート番号入力欄  -->
        <Label
            x:Name="lblPort"
            Margin="15,141,0,0"
            HorizontalAlignment="Left"
            VerticalAlignment="Top"
            Content="ポート番号：" />
        <TextBox
            x:Name="txtPort"
            Width="280"
            Margin="90,128,0,0"
            HorizontalAlignment="Left"
            VerticalAlignment="Top"
            materialDesign:HintAssist.Hint="ポート番号を入力してください。"
            Style="{StaticResource MaterialDesignFloatingHintTextBox}" />

        <!--  送信するデータ入力欄  -->
        <Label
            x:Name="lblSendData"
            Margin="15,183,0,0"
            HorizontalAlignment="Left"
            VerticalAlignment="Top"
            Content="送信データ：" />
        <TextBox
            x:Name="txtSendData"
            Width="280"
            Margin="90,170,0,0"
            HorizontalAlignment="Left"
            VerticalAlignment="Top"
            Text="Hello"
            materialDesign:HintAssist.Hint="送信するデータを入力してください。"
            Style="{StaticResource MaterialDesignFloatingHintTextBox}" />

        <!--  送信開始ボタン  -->
        <Button
            x:Name="btnStart"
            Width="90"
            Height="30"
            Margin="0,177,10,0"
            HorizontalAlignment="Right"
            VerticalAlignment="Top"
            Click="BtnStart_Click"
            Content="送信開始"
            Foreground="Black"
            Style="{StaticResource MaterialDesignOutlinedButton}" />

        <!--  ログ出力欄  -->
        <TextBox
            x:Name="txtLog"
            Margin="10,215,10,10"
            AcceptsReturn="True"
            IsEnabled="{Binding ElementName=MaterialDesignOutlinedTextBoxEnabledComboBox}"
            Style="{StaticResource MaterialDesignOutlinedTextBox}"
            TextWrapping="Wrap"
            VerticalScrollBarVisibility="Auto" />
    </Grid>
</Window>

public partial class MainWindow : Window
{
    tcpclient tcp = new tcpclient();

    public MainWindow()
    {
        InitializeComponent();
    }

    private async void btnStart_Click(object sender, RoutedEventArgs e)
    {
        var responce = await tcp.StartClient(txtIpaddress.Text, int.Parse(txtPort.Text), txtSendData.Text);
        MessageBox.Show(responce);
    }
}