Xamarin.Forms GestureRecognizers无法在Command上运行

问题描述

xaml页面中的代码:

Code in the xaml page:

  <StackLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand">
            <CollectionView ItemsSource="{Binding MeniElementi}">
                <CollectionView.ItemsLayout>
                    <GridItemsLayout Orientation="Vertical"
                        Span="2" />
                </CollectionView.ItemsLayout>
                <CollectionView.ItemTemplate>
                    <DataTemplate>
                        <Frame Padding="10" WidthRequest="140" HeightRequest="140">
                            <Frame BackgroundColor="AliceBlue" WidthRequest="120" HeightRequest="120" HasShadow="True" CornerRadius="10" Padding="10" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand" >
                                <StackLayout>
                                    <Image Source="http://www.clker.com/cliparts/l/u/5/P/D/A/arrow-50x50-md.png"  WidthRequest="70" HeightRequest="70"  >
                                        <Image.GestureRecognizers>
                                            <TapGestureRecognizer
                                                     Command="{Binding LoadElements}"

                                                       />
                                        </Image.GestureRecognizers>
                                    </Image>
                                    <Label Text="{Binding Title}" HeightRequest="50" WidthRequest="100" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" />
                                </StackLayout>
                            </Frame>
                        </Frame>
                    </DataTemplate>
                </CollectionView.ItemTemplate>
            </CollectionView>

        </StackLayout>

xaml.cs中的代码:

Code in xaml.cs:

[XamlCompilation(XamlCompilationOptions.Compile)] 公共局部类菜单:ContentPage {

[XamlCompilation(XamlCompilationOptions.Compile)] public partial class Menu: ContentPage {

    MenuViewModel viewModel = new MenuViewModel();
    public Menu()
    {
        InitializeComponent();
        BindingContext = viewModel;
    }



}

viewmodel.cs中的代码

Code in viewmodel.cs

 public class MenuViewModel :BaseViewModel, INotifyPropertyChanged
    {
        public Command LoadElements { get; set; }

        public ObservableCollection<Meni> MeniElementi { get; set; }
        public MenuViewModel()
        {

            LoadElements= new Command(execute: async () => await ExecuteElements());
            MeniElementi = new ObservableCollection<Meni>() {

            new Meni(){Title="Transatcions" ,Picture="xxx"},
            new Meni(){Title="Transatcions" ,Picture="xxx"},
       };
        }
        async Task ExecuteElements()
        {
            try
            {
                await Application.Current.MainPage.Navigation.PushAsync(new InfoPage());
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex);
            }
            finally
            {
            }
        }

LoadElements命令未触发.正在加载开始菜单，显示菜单元素只是命令无法导航到另一个页面.使用Xamarin.Forms.Command.在其他可以正常使用Command的页面上

LoadElements Command not fired. Loading starting menu , showing menu elements just command not working to navigate to another page. Using Xamarin.Forms.Command. On other pages working normal with Command

推荐答案

您可以重置水龙头的绑定路径.这样您就可以在同一命令中处理逻辑.

You could reset the binding path of the tap . So that you can handle the logic in the same command .

<?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:d="http://xamarin.com/schemas/2014/forms/design"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             mc:Ignorable="d"
             x:Name="Page"   //set the name of page
             x:Class="xxx.xxxPage">

<TapGestureRecognizer Command="{Binding Source={x:Reference Page},Path=BindingContext.LoadElements}"

这篇关于Xamarin.Forms GestureRecognizers无法在Command上运行的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！