在UWP中从数据库中检索数据

Question

I'm trying to retrieve a list of data from SQLDatabase on Azure and bind it on a listview in my universal application for windows 10. What I've done is creating a WCF service for retrieving the data, then publish on azure, after that calling this service on my application.

There are errors in my current code. This is my code for IService1.cs

namespace WcfService2
{
    // NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService1" in both code and config file together.
    [ServiceContract]
    public interface IService1
    {
        // TODO: Add your service operations here
        [OperationContract]
        List<NYPUnlocking> NYP_GetLockerStatus();
    }


    // Use a data contract as illustrated in the sample below to add composite types to service operations.
    [DataContract]
    public class NYPUnlocking
    {
        [DataMember]
        public int lockerID { get; set; }
        [DataMember]
        public string lockStatus { get; set; }
    }

}

Service1.svc.cs:

namespace WcfService2
{
    // NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service1" in code, svc and config file together.
    // NOTE: In order to launch WCF Test Client for testing this service, please select Service1.svc or Service1.svc.cs at the Solution Explorer and start debugging.
    public class Service1 : IService1
    {
       public List<NYPUnlocking> NYP_GetLockerStatus()
        {
            SqlConnection conn = new SqlConnection("Copy ADO.net connection string");
            string sqlStr = "SELECT * FROM dbo.lockerStatus";
            SqlCommand cmd = new SqlCommand(sqlStr, conn);
            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            List<NYPUnlocking> ret = new List<NYPUnlocking>();
            while (dr.Read())
            {
                NYPUnlocking unlock = new NYPUnlocking()
                {
                    lockerID = Int32.Parse(dr["lockerID"].ToString()),
                    lockStatus = dr["lockStatus"].ToString()
                };

                ret.Add(unlock);
            }
            conn.Close();

            return ret;
        }
    }
}

I then publish it on Azure and add a service reference to the azure website on my UWP application. The following codes are my XAML and cs codes.

I'm having error at x:DataType="data:NYPUnlocking", the error saying "The name "NYPUnlocking" does not exist in the namespace "using:NYPUnlock.ServiceReference1".

<Page.Resources>
    <DataTemplate x:DataType="data:NYPUnlocking" x:Key="UserTemplate">
        <StackPanel Orientation="Horizontal" Padding="0,0,0,0">
            <TextBlock FontSize="12" Text="{x:Bind lockerID}" HorizontalAlignment="Left" Width="200" />
            <TextBlock FontSize="12" Text="{x:Bind lockStatus}" HorizontalAlignment="Right" Width="200" />
        </StackPanel>
    </DataTemplate>
</Page.Resources>

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Width="354">
        <ListView x:Name="lvLocker" ItemTemplate="{StaticResource UserTemplate}"/>
        <TextBox x:Name="tbError" TextWrapping="Wrap" Text="Error"/>
    </StackPanel>
</Grid>

And my cs file is having error at await task1 saying "Cannot implicitly convert type 'System.Collections.ObjectModel.ObservableCollection' to 'NYPUnlock.ServiceReference1.NYPUnlocking[]'

namespace NYPUnlock
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();
            getStatus();
        }
        public async void getStatus()
        {
            try
            {
                ServiceReference1.Service1Client client = new ServiceReference1.Service1Client(ServiceReference1.Service1Client.EndpointConfiguration.BasicHttpBinding_IService1);
                var task1 = client.NYP_GetLockerStatusAsync();
                ServiceReference1.NYPUnlocking[] returnResult = await task1;
                lvLocker.ItemsSource = returnResult;
            }
            catch(Exception ex)
            {
                tbError.Text = ex.Message;
            }
        }
    }
}

I think I am doing everything correctly, what could be causing the problem? Any help is greatly appreciated, thanks!

Answer 1

Try that:

• Add a reference called "whatevername" to the namespace WcfService2 in your XAML file and use this prefix instead of "data:" in x:DataType="data:NYPUnlocking"

• Replace the declaration of returnResult with var type instead of ServiceReference1.NYPUnlocking[] type