如何再次选择已经选择的gridview项目

Question

我需要选择一个已经选择的 Gridview 项目。但是一旦选择它就不会第二次触发 PropertyChanged。我尝试将 SelectedIndex 重置为 -1 并将 SelectedItem 重置为 null。没有运气。 任何帮助将不胜感激。

<GridView
            x:Name="OrganizationsGridView"
            HorizontalAlignment="Center"
            ItemContainerStyle="{StaticResource GridViewItemStyle11}"
            ItemsSource="{Binding OrganizationsList}"
            SelectedIndex="{Binding SelectedIndex, Mode=Twoway}"
            SelectedItem="{Binding SelectedOrganization, Mode=Twoway, UpdateSourceTrigger=PropertyChanged}"
            Tag="{Binding OrganizationsList}">

Answer 1

您可以在 SelectionChanged 事件发生之前将 SelectedIndex 设置为 -1，这可以触发所选项目的 PropertyChanged 事件。同时，使用该方法会导致在选择item的过程中多次触发PropertyChanged事件。

请参考以下代码。

XAML 代码：

<Page
   ..>
    <Grid>
            <GridView x:Name="gridview" ItemsSource="{x:Bind persons}"
                      SelectedIndex="{x:Bind SelectedIndex, Mode=TwoWay}"
                      IsItemClickEnabled="True"
                      ItemClick="gridview_ItemClick">
                <GridView.ItemTemplate>
                    <DataTemplate x:DataType="local:Person">
                        <TextBlock Text="{x:Bind name}" FontWeight="Bold"  />
                    </DataTemplate>
                </GridView.ItemTemplate>
            </GridView>           
    </Grid>
</Page> 

后面的代码：

namespace SelectedGridview
{
    public sealed partial class MainPage : Page,INotifyPropertyChanged
    {
        public ObservableCollection<Person> persons { get; set; }
        private int _SelectedIndex;
        public int SelectedIndex
        {
            get { return _SelectedIndex; }
            set
            {
                _SelectedIndex = value;
                RaisePropertyChanged("SelectedIndex");
            }
        }
        public MainPage()
        {
            this.InitializeComponent();
            persons = new ObservableCollection<Person>
            {
                new Person(){name="Lily",age=45},
                new Person(){name="tom",age=21},
                new Person(){name="jack",age=37},
                new Person(){name="loean",age=26},
                new Person(){name="jojo",age=18}      
            
            };
         
        }

        public event PropertyChangedEventHandler PropertyChanged;
        public void RaisePropertyChanged([CallerMemberName] string propertyname = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyname));
            
        }     

        private void gridview_ItemClick(object sender, ItemClickEventArgs e)
        {
            SelectedIndex = -1;
        }    
    }
    public class Person
    {
        public string name { get; set; }
        public int age { get; set; }
    }
}