自从我在Xamarin中编写应用程序以来，我一直在努力解决这个问题。问题是当我想从ContentPage的Main方法之外更改标签的文本值时，它不会在用户界面上更新。

public partial class MainPage : ContentPage
{
int command = 0;
SimpleTcpServer server1 = null;
SimpleTcpServer server2 = null;
System.Timers.Timer timer = null;
string iPPort = null;
public string Data { get; set; } = "getting data";

public MainPage()
{
    InitializeComponent();
    NetworkAccess accessType = Connectivity.Current.NetworkAccess;
    if (accessType == NetworkAccess.Internet)
    {
        server1 = new SimpleTcpServer("10.0.0.9:10000");
        server2 = new SimpleTcpServer("10.0.0.9:11000");
        timer = new System.Timers.Timer(150);
        timer.Elapsed += Tick;
        timer.AutoReset = true;
        server1.Events.ClientConnected += ClientConnected;
        server1.Events.ClientDisconnected += ClientDisconnected;
        server2.Events.ClientConnected += ClientConnected2;
        server2.Events.ClientDisconnected += ClientDisconnected2;
        server2.Events.DataReceived += DataReceived2;
        label.Text = Data;
        server1.Start();
        server2.Start();
        
    }
}

public void DataReceived2(object sender, SuperSimpleTcp.DataReceivedEventArgs e)
{
    ArraySegment<byte> buffer = e.Data;
    Data = Encoding.Default.GetString(buffer);
    label.Text = Data;
}

private void ClientDisconnected2(object sender, ConnectionEventArgs e)
{
    throw new NotImplementedException();
}

private void ClientConnected2(object sender, ConnectionEventArgs e)
{
}

private void Tick(object sender, ElapsedEventArgs e)
{
    server1.Send(iPPort, command.ToString());
}



private void ClientDisconnected(object sender, ConnectionEventArgs e)
{
    throw new NotImplementedException();
}

private void ClientConnected(object sender, ConnectionEventArgs e)
{
    iPPort = e.IpPort;
    timer.Start();
}

private void Forward(object sender, EventArgs e)
{
    command = 1;
}

private void Backward(object sender, EventArgs e)
{
    command = 2;
}

private void Left(object sender, EventArgs e)
{
    command = 3;
}

private void Right(object sender, EventArgs e)
{
    command = 4;
}

private void Released(object sender, EventArgs e)
{
    command = 0;
}

}

这是我的. NETMaui C#程序，它基本上创建了两个Tcp侦听器，侦听两个端口-一个用于发送，一个用于接收（由于项目的第二部分，因此在两个不同的端口上很重要）。当从第二个端口接收到数据时（接收端口）引发方法DataReceived2，它获取数据并使用数据更改标签文本值。当我调试程序时，我看到标签的值被更改为它应该是什么，但它没有在ContentPage上更改。我也尝试了数据绑定，但结果是一样的。

<StackLayout>
    <Grid x:Name="grid">
        <StackLayout VerticalOptions="CenterAndExpand" Margin="10,290,0,0">
            <StackLayout Orientation="Horizontal">
                <StackLayout Margin="0,120,0,60">
                    <Button VerticalOptions="CenterAndExpand" BackgroundColor="Green"  Pressed="Forward" Released="Released" CornerRadius="50" Margin="0,0,0,-20" HeightRequest="100" WidthRequest="100"></Button>
                    <Button HeightRequest="100" Pressed="Backward" BackgroundColor="Green" Released="Released" WidthRequest="100" CornerRadius="50"></Button>
                </StackLayout>
                <StackLayout Margin="20,200,0,120" Orientation="Horizontal">
                    <Button CornerRadius="100" Pressed="Left" BackgroundColor="Green" Released="Released" HeightRequest="100" WidthRequest="100"></Button>
                    <Button HeightRequest="100" Pressed="Right" BackgroundColor="Green" Released="Released" Margin="10,0,0,0" WidthRequest="100" CornerRadius="60"></Button>
                </StackLayout>
            </StackLayout>
        </StackLayout>
        <StackLayout x:Name="stack">
            <Label x:Name="label" Text="" HorizontalOptions="CenterAndExpand" VerticalOptions="CenterAndExpand"/>
        </StackLayout>
    </Grid>

</StackLayout>

这是我的xaml代码。有人能帮我解决这个问题吗？