Question

我试图通过Event SwipeEnded从刷过的行中获取数据但SwipeEnded事件返回没有数据的选择项

xaml代码

    <?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:prism="clr-namespace:Prism.Mvvm;assembly=Prism.Forms"
             prism:ViewModelLocator.AutowireViewModel="True"
             xmlns:sfgrid="clr-namespace:Syncfusion.SfDataGrid.XForms;assembly=Syncfusion.SfDataGrid.XForms"
             xmlns:b="clr-namespace:Xamarin.Behaviors;assembly=Xamarin.Behaviors"
             x:Class="PrismUnityApp2.Views.Hovedside"
             xmlns:sys="clr-namespace:System;assembly=mscorlib"
             Title="test">

  <ContentPage.Content>
    <Grid>
      <Grid.RowDefinitions>
        <RowDefinition Height="20" />
        <RowDefinition Height="50"/>
        <RowDefinition  Height="*" />
        <RowDefinition Height="50" />
        <RowDefinition Height="50" />
      </Grid.RowDefinitions>

      <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
        <ColumnDefinition Width="*"/>
        <ColumnDefinition Width="*"/>
      </Grid.ColumnDefinitions>

      <DatePicker Date="{Binding SelectedDate,Mode=TwoWay}" MinimumDate="{Binding MinimumSelectedDate,Mode=TwoWay}" Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="3" HorizontalOptions="Center">
        <DatePicker.Format>dd-MM-yyyy</DatePicker.Format>
      </DatePicker>

      <sfgrid:SfDataGrid x:Name="dataGrid"
                  AutoGenerateColumns="False"
                  AllowSwiping="true"
                  ColumnSizer="Star"
                  SelectedIndex="1"
                  SelectionMode="Single"
                 ItemsSource="{Binding ToemmeListe}"
                   AllowSorting="True"
                          Grid.Row="2"
                          Grid.Column="0" Grid.ColumnSpan="3"
                         >
        <b:Interaction.Behaviors>
          <b:BehaviorCollection>
            <b:EventToCommand Command="{Binding SelectionCommand}"
                              CommandParameter="{x:Reference Name=dataGrid}"
                              EventName="SelectionChanged" />
          <b:EventToCommand Command="{Binding SwipeCommand}"
                             CommandParameter="{x:Reference Name=dataGrid}"
                             EventName="SwipeEnded" />
          </b:BehaviorCollection>
        </b:Interaction.Behaviors>
        <sfgrid:SfDataGrid.Columns x:TypeArguments="syncfusion:Columns">
          <sfgrid:GridTextColumn HeaderText="Fraktion"
                                     MappingName="Fraktion" />
          <!--Fraktion-->
          <sfgrid:GridTextColumn HeaderText="Type"
                                     MappingName="Type" />
          <!--Type-->
          <sfgrid:GridTextColumn HeaderText="Vaegt"
                                   MappingName="Vaegt" />
          <!--vægt-->
        </sfgrid:SfDataGrid.Columns>

        <sfgrid:SfDataGrid.LeftSwipeTemplate>
          <DataTemplate>
            <ContentView BackgroundColor="#1AAA87" >
              <Grid IsVisible="True">
                <Grid.ColumnDefinitions>
                  <ColumnDefinition Width ="20" />
                  <ColumnDefinition Width ="*" />
                </Grid.ColumnDefinitions>

                <Label Grid.Column="1"
                    Text ="Slet"
                    HorizontalTextAlignment="Start"
                    VerticalTextAlignment="Center"
                    LineBreakMode ="NoWrap"
                    BackgroundColor="Red"
                    TextColor ="White"/>


              </Grid>
            </ContentView>
          </DataTemplate>
        </sfgrid:SfDataGrid.LeftSwipeTemplate>

      </sfgrid:SfDataGrid>


      <Button Text="Menu" FontSize="24" Grid.Row="4" Grid.Column="0" Grid.ColumnSpan="3" HorizontalOptions="Center" Command="{Binding popup}"/>

    </Grid>


  </ContentPage.Content>

</ContentPage>

主视图模型

using Prism.Commands;
using Prism.Mvvm;
using Prism.Navigation;
using Syncfusion.SfDataGrid.XForms;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;
using System.ServiceModel;
using System.Threading.Tasks;
using Xamarin.Forms;

namespace PrismUnityApp2.ViewModels
{


    public class HovedsideViewModel : BindableBase, INotifyPropertyChanged, INavigationAware
    {
        MobileService.VaksServiceClient ws = new MobileService.VaksServiceClient();
        INavigationService _navigationService;
        public event PropertyChangedEventHandler PropertyChanged;


        #region Properties
        private DateTime selectedDate;
        public DateTime SelectedDate
        {
            get { return selectedDate; }
            set
            {
                if (selectedDate != value)
                {
                    selectedDate = value;

                    if (PropertyChanged != null)
                    {
                        PropertyChanged(this,
                            new PropertyChangedEventArgs("SelectedDate"));

                    }
                }
            }
        }

        private DateTime minimumSelectedDate;
        public DateTime MinimumSelectedDate
        {
            get { return minimumSelectedDate; }
            set
            {
                if (minimumSelectedDate != value)
                {
                    minimumSelectedDate = value;

                    if (PropertyChanged != null)
                    {
                        PropertyChanged(this,
                            new PropertyChangedEventArgs("MinimumSelectedDate"));
                    }
                }
            }
        }

        public DelegateCommand Navigatetest { get; private set; }
        public DelegateCommand NavigateToBestilling { get; private set; }
        public DelegateCommand popup { get; private set; }

        public string latitude { get; set; }
        private string _longitude;

        public string longitude
        {
            get { return _longitude; }
            set { _longitude = value; }
        }

        public String PladsID { get; set; }

        private ObservableCollection<ToemningData> toemmeListe;

        public ObservableCollection<ToemningData> ToemmeListe
        {
            get { return toemmeListe; }
            set { this.toemmeListe = value; }
        }
        #endregion



        public HovedsideViewModel(INavigationService navigationService)
        {

            SetRowData(); // initialize the grid


            SelectedDate = DateTime.Today.AddDays(1);


            _navigationService = navigationService;
            Navigatetest = new DelegateCommand(Navigate);
            NavigateToBestilling = new DelegateCommand(_NavigateToBestilling);
            popup = new DelegateCommand(_popup);

            selectionCommand = new Command<SfDataGrid>(onSelectionChanged);
            swipeCommand = new Command<SfDataGrid>(onSwipeChanged);
            selectedItems = new ObservableCollection<object>();
        }

        private Command<SfDataGrid> selectionCommand;
        public Command<SfDataGrid> SelectionCommand
        {
            get { return selectionCommand; }
            set { selectionCommand = value; }
        }

        private Command<SfDataGrid> swipeCommand;
        public Command<SfDataGrid> SwipeCommand
        {
            get { return swipeCommand; }
            set { swipeCommand = value; }
        }

        private ObservableCollection<object> selectedItems;

        public ObservableCollection<object> SelectedItems
        {
            get { return selectedItems; }
            set { selectedItems = value; }
        }

        private void onSelectionChanged(SfDataGrid obj)
        {
            //gets the selected items in the datagrid
            selectedItems = obj.SelectedItems;
        }

        private void onSwipeChanged(SfDataGrid obj)
        {

            selectedItems = obj.SelectedItems;  // returns null on all properties
        }




        async void _popup()
        {
            Xamarin.Forms.Device.BeginInvokeOnMainThread(async () =>
            {
                var action = await App.Current.MainPage.DisplayActionSheet("ActionSheet: SavePhoto?", null, null, "Manuel bestilling", "Scan", "Send", "Fortryd");
                switch (action)
                {
                    case "Manuel bestilling":
                        _NavigateToBestilling();
                        break;
                    case "Scan":
                        Navigate();
                        break;
                    case "Send":
                        // TODO make webservice that sends recipe
                        break;
                    case "Fortryd":
                        // Nothing
                        break;
                    default:
                        break;
                }
            });


        }

        MobileService.Toemning ToWCFServiceTodoItem(MobileService.Toemning item)
        {
            return new MobileService.Toemning
            {
                Fraktion = item.Fraktion,
                ToemmeId = item.ToemmeId,
                Type = item.Type,
                date = item.date,
                Latitude = item.Latitude,
                Longitude = item.Longitude,
                Weight = item.Weight,
                PladsId = item.PladsId
            };
        }


        public async Task<ObservableCollection<MobileService.Toemning>> CallService(MobileService.Toemning item)
        {
            var todoItem = ToWCFServiceTodoItem(item);
            MobileService.VaksServiceClient client = new MobileService.VaksServiceClient(new BasicHttpBinding(), new EndpointAddress("http://kss.vestfor.dk/Vaks2Svc/VaksService.svc?singleWsdl"));
            var t = Task<ObservableCollection<MobileService.Toemning>>.Factory.FromAsync(
                    ((MobileService.IVaksService)client.InnerChannel).BeginGetToemmeDatasByPladsId,
                    ((MobileService.IVaksService)client.InnerChannel).EndGetToemmeDatasByPladsId,
                     todoItem, TaskCreationOptions.None);
            return await t;
        }

        public void SetRowData()
        {

            try
            {
                toemmeListe = new ObservableCollection<ToemningData>();
            }
            catch (Exception ex)
            {

                throw;
            }

            ToemningData _ToemningData = new ToemningData();
            _ToemningData.Parent = this;
            ToemmeListe.Add(_ToemningData);
        }



        #region Navigation
        private void _NavigateToBestilling()
        {
            var p = new NavigationParameters();
            p.Add("pladsid", PladsID);
            var ttttt = DateTime.Today;
            if (SelectedDate.Date > DateTime.Now.Date)
            {
                p.Add("selecteddate", SelectedDate);
            }
            _navigationService.NavigateAsync("Bestilling", p);

        }

        private void Navigate()
        {
            var p = new NavigationParameters();
            p.Add("pladsid", PladsID);
            p.Add("selecteddate", SelectedDate);
            _navigationService.NavigateAsync("Scanner", p);
        }

        public void OnNavigatedFrom(NavigationParameters parameters)
        {

        }

        public async void OnNavigatedTo(NavigationParameters parameters)
        {
            PladsID = parameters["pladsid"].ToString();


            if (parameters.ContainsKey("selecteddate"))   
            {

                SelectedDate = DateTime.Parse(parameters["selecteddate"].ToString());
            }
            GridUpdate();
        }
        #endregion

        public void GridUpdate()
        {
            Xamarin.Forms.Device.BeginInvokeOnMainThread(async () =>
            {
                // if the phone inst near latitude "55,7070631" and longitude "12,4235393" then remove the part where it gets data from parameters
                // and use the two lines under this
                //latitude = "55,7070631";
                //longitude = "12,4235393";
                var ggg = await CallService(new MobileService.Toemning { PladsId = Convert.ToInt32(PladsID), date = new DateTime(2016, 11, 1) });  // the date is set to a day where there is data  // TODO set date = DateTime.Today.AddDays(1);

                ToemmeListe.Clear();
                foreach (var toemming in ggg)
                {

                    ToemningData _ToemningData = new ToemningData();
                    _ToemningData.Parent = this;
                    _ToemningData.Fraktion = toemming.Fraktion;
                    _ToemningData.ToemmeID = toemming.ToemmeId;
                    _ToemningData.Type = toemming.Type;
                    _ToemningData.Vaegt = toemming.Weight;
                    ToemmeListe.Add(_ToemningData);
                }

            });

        }

        public void GridDelete()
        {

        }

    }
}

行使用的ViewModel会被发送到主ViewModel

using Prism.Commands;
using System;
using System.ComponentModel;
using Xamarin.Forms;

namespace PrismUnityApp2.ViewModels
{
    public class ToemningData : INotifyPropertyChanged
    {

        public DelegateCommand DeleteRow { get; private set; }

        public ToemningData()
        {
            DeleteRow = new DelegateCommand(_DeleteRow);
        }



        private void _DeleteRow() // Do not delete anything from yesterday or before
        {
            // TODO get the ID of the selected(swiped) ROW
            // TODO sendt it to GridDelete() where it will make a WS call and remove that row of data
            //Parent.GridDelete();
            Parent.GridUpdate();

        }


        private int toemmeID { get; set; }
        public int ToemmeID
        {
            get
            {
                return toemmeID;
            }
            set
            {
                this.toemmeID = value;
                RaisePropertyChanged("ToemmeID");
            }
        }

        private string fraktion { get; set; }
        public string Fraktion
        {
            get
            {
                return fraktion;
            }
            set
            {
                this.fraktion = value;
                RaisePropertyChanged("Fraktion");
            }
        }

        private string type { get; set; }
        public string Type
        {
            get
            {
                return type;
            }
            set
            {
                this.type = value;
                RaisePropertyChanged("Type");
            }

        }

        private string vaegt { get; set; }
        public string Vaegt
        {
            get
            {
                return vaegt;
            }
            set
            {
                this.vaegt = value;
                RaisePropertyChanged("Vaegt");
            }
        }

        private string transportType { get; set; }
        public string TransportType
        {
            get
            {
                return transportType;
            }
            set
            {
                this.transportType = value;
                RaisePropertyChanged("TransportType");
            }
        }

        private int transportTypeID { get; set; }
        public int TransportTypeID
        {
            get
            {
                return transportTypeID;
            }
            set
            {
                this.transportTypeID = value;
                RaisePropertyChanged("TransportTypeID");
            }
        }

        private string pickerfraktion { get; set; }
        public string PickerFraktion
        {
            get
            {
                return pickerfraktion;
            }
            set
            {
                this.pickerfraktion = value;
                RaisePropertyChanged("PickerFraktion");
            }
        }

        private int pickerfraktionID { get; set; }
        public int PickerFraktionID
        {
            get
            {
                return pickerfraktionID;
            }
            set
            {
                this.pickerfraktionID = value;
                RaisePropertyChanged("PickerFraktionID");
            }
        }

        public HovedsideViewModel Parent { get; internal set; }

        #region INotifyPropertyChanged implementation

        public event PropertyChangedEventHandler PropertyChanged;

        private void RaisePropertyChanged(String Name)
        {
            if (PropertyChanged != null)
                this.PropertyChanged(this, new PropertyChangedEventArgs(Name));
        }

        #endregion
    }
}

有什么方法可以通过滑动而不是从行中获取数据使用SelectionChanged事件？

即时通讯使用visual studio 2015社区，xamarin.Forms 2.3.3.168，prism v6.2.0 Syncfusion 14.4.0.15。主要是在Android版6.0.1和使用API 23的sony xperia z3上运行它我也在虚拟iphone 6s和IOS 10.0上使用它进行测试

非常感谢任何帮助

Answer 1

您可以通过处理RowData事件来获取SwipeEnded。 SwipeEndedEventArgs有RowData。请参考下面的代码示例。

private void dataGrid_SwipeEnded(object sender, SwipeEndedEventArgs e)
{
   var rowdata = e.RowData;
}

Answer 2

问题是您需要创建一个转换器，以将事件args放入视图模型。如果您查看here的源代码，您会发现您需要一个转换器来获取值。我将SwipeEnded事件的EventToCommand行为更改为此：

<b:EventToCommand 
    EventName="SwipeEnded"
    Command="{Binding SwipeCommand}"
    EventArgsConverter="{StaticResource swipeEndedEventArgsConverter}" />

然后使用这样的转换器：

public class SwipeEndedEventArgsConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var itemSwipeEndedEventArgs = value as SwipeEndedEventArgs;
        if (itemSwipeEndedEventArgs == null)
        {
            throw new ArgumentException($"Expected value to be of type {nameof(SwipeEndedEventArgs)}", nameof(value));
        }
        return itemSwipeEndedEventArgs;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

请记住将其添加到资源字典中，以便您可以在XAML中使用它，例如，从内容页面资源中使用它：

<ContentView.Resources>
    <ResourceDictionary>
        <converters:SwipeEndedEventArgsConverter x:Key="swipeEndedEventArgsConverter" />
    </ResourceDictionary>
</ContentView.Resources>

并将命名空间也添加到xaml：

xmlns:converters="clr-namespace:Project.Converters;assembly=Project"

从syncfusion datagrid获取Swiped Row id

2 个答案: