Question

我正在通过xamarin.Forms中的pubnub尝试聊天应用程序，我可以通过保留断点登录到我理解的频道。现在我正在尝试获取登录到我的频道的人员列表。< / p>

<ContentPage.Content>
    <StackLayout HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
        <Label Text="Welcome" TextColor="Blue" HorizontalOptions="Center" VerticalOptions="Center">
            <Label.FontSize>
                <OnIdiom x:TypeArguments="x:Double">
                    <OnIdiom.Phone>
                        <OnPlatform x:TypeArguments="x:Double" iOS="20" Android="20" WinPhone="20" />
                    </OnIdiom.Phone>
                    <OnIdiom.Tablet>
                        <OnPlatform x:TypeArguments="x:Double" iOS="30" Android="30" WinPhone="30" />
                    </OnIdiom.Tablet>
                </OnIdiom>
            </Label.FontSize>
        </Label>
        <ListView x:Name="LoginUserList" ItemsSource="{Binding LoginUserList}"ItemSelected="LoginUserList_OnItemSelected">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>
                        <StackLayout Orientation="Horizontal">
                            <Label Text="{Binding UserName}" TextColor="SkyBlue" FontSize="20" HorizontalOptions="Center" VerticalOptions="Center"></Label>
                        </StackLayout>
                    </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>
    </StackLayout>
</ContentPage.Content>

这里如何显示登录用户列表。

public class ChatListViewModel : INotifyPropertyChanged
{
    private List<UserDto> _loginUserList;
    private string _offlineImageSource;
    private bool _offlineVisibility;
    private string _userName;

    public ChatListViewModel()
    {
        InitializeData();
        GetAllUsersFromServer();
    }

    public event PropertyChangedEventHandler PropertyChanged;

    public List<UserDto> LoginUserList
    {
        get { return _loginUserList; }
        set
        {
            _loginUserList = value;
            OnPropertyChanged();
        }
    }

    public string OfflineImageSource
    {
        get { return _offlineImageSource; }
        set
        {
            _offlineImageSource = value;
            OnPropertyChanged();
        }
    }

    public string UserName
    {
        get { return _userName; }
        set
        {
            _userName = value;
            OnPropertyChanged();
        }
    }

    public bool OfflineVisibility
    {
        get { return _offlineVisibility; }
        set
        {
            _offlineVisibility = value;
            OnPropertyChanged();
        }
    }

    private async void GetAllUsersFromServer()
    {
       LoginUserList = await UserService.Instance.GetAllUsers();
    }

            protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    private void InitializeData()
    {
        OfflineImageSource = "BlackCircle.png";
    }
}

这是用于列表显示目的的ViewModel。

Answer 1

您可以使用on＆＃34; connect＆＃34;来获取PubNub频道上的活跃订阅者/用户列表。打回来。您将提供on＆＃34; connect＆＃34;当新用户或现有用户连接时要调用的函数。发生这种情况时，您会将此信息转发到最终需要的位置。

我将向您展示一些示例代码：

PUBNUB.subscribe({
    channel    : "hello_world",      // CONNECT TO THIS CHANNEL.
    callback   : function(message){} // RECEIVED A MESSAGE.
    connect    : function() {        // CONNECTION ESTABLISHED.
        // A new user or existing user has
        // connected.  Send details to your server.

        // ---------------------------------------
        // This is a psudo-code example function:
        // ---------------------------------------
        psudo_post_url( "http://www.mywebsite.com/pubnub-user-connected", {
            "user_id" : 123456789,
            "channel" : "hello_word"
        } );
    }
})

如何获取登录用户列表-pubnub

1 个答案: