Question

我的儿童认为,我收集了资料。

 <CollectionView  SelectionMode="Single" SelectedItem="{Binding Source={Reference sideview}, Path=myViewModel.SelectedItem.FileName}"
                     ItemsSource="{Binding Source={x:Reference sideview}, Path=myViewModel.Items }" >
            <CollectionView.ItemTemplate>
            <DataTemplate >
                <Grid>
                <Label Text="{Binding FileName}"   VerticalOptions="Center"/>
                </Grid>
            </DataTemplate>
        </CollectionView.ItemTemplate>
    </CollectionView>

I want to delete selected item My parent view where I have delete button

      <Button x:Name="BTN_REMOVE_FILE"  Text="Remove" Command="{Binding DeleteCommand}" CommandParameter="{Binding SelectedItem}" >

I have created delete command in my viewmodel

   [RelayCommand]
    public void Delete(Data s)
    {
        if (Items.Contains(s)) {
            Items.Remove(s);
        }  
    }

从我看来,我已经从指挥参数的角度来看待了。

我还在我看来建立了选定项目模式。

 public Data selectedItem;
    public Data SelectedItem
    {
        get
        {
            return selectedItem;
        }
        set
        {
            if(selectedItem != value)
            {
                selectedItem = value;
            }
        }
    }`public MyViewModel()
    {

        Items = new ObservableCollection<Data>();
        selectedItem = new Data();
    }
    `

它表明我有例外,例如“直径”的“直径”(目标)不能是类型。 DemoApp.MVVM.ViewModel.MyViewModel,因为指挥类型需要辨别Dap。 MVVM.Model。数据(参数参数)

在我看来,添加这一句数据名称{到处;

参考: <Button x:Name=“BTN_REMOVE_FILE” 文本=“Remove”突击=“{具有约束力的删除Command}” 指挥Paraile=“{具有约束力的名称}”

Answer 1


为<条码>创建财产 您认为,
public Data selectedItem;
public Data SelectedItem
{
    get
    {
        return selectedItem;
    }
    set
    {
        if (selectedItem != value)
            selectedItem = value;
    }
}

3. 规定,从概念角度看,财产为:
public MyViewModel()
{
    Items = new ObservableCollection<Data>();
    SelectedItem = new Data();
}

然后,制定删除方法并通过选定项目:
public void Delete()
{
    if (Items.Contains(SelectedItem))
        Items.Remove(SelectedItem);
}

最后,对选定的公司具有约束力 收集观点的财产:
<CollectionView  SelectionMode="Single" SelectedItem="{Binding Source={Reference sideview}, Path=myViewModel.SelectedItem}">

当你使用<代码>代号()方法时,选定项目被删除。例如,我对这种方法有了一个子:

<Button Text="Remove selected item" Command="{Binding DeleteCommand}" />

Answer 2

Command="{Binding Source={RelativeSource AncestorType={x:Type viewmodel:MyViewModel}}, Path=DeleteCommand}"

澄清一个范围:

您必须留在数据表内(根据您的收件编号项目图2)。

{Binding .}

作为突击性参数。

要想在这种数据表内,你必须走一等,以便你找到你在你的视野中指挥的道路。

Answer 3

您可使用以下代码在收集意见中删除该项目。

In the Mainpage.xaml

<CollectionView ItemsSource="{Binding Products}">
        <CollectionView.ItemTemplate>
            <DataTemplate>
                
                    <StackLayout>
                        <Label Text="{Binding Name}" />
                        <Label Text="{Binding Price}" />
                        <Button Text="Remove" Clicked="Remove_Clicked" />
                    </StackLayout>
                
            </DataTemplate>
        </CollectionView.ItemTemplate>
    </CollectionView>

In the Mainpage.xaml.cs

  public partial class MainPage : ContentPage
    {
        public MainPage()
        {
            InitializeComponent();
            BindingContext = new ProductsViewModels();
        }
        public void Remove_Clicked(object sender, EventArgs e)
        {
            var button = sender as Button;
            var product = button.BindingContext as Products;
            var vm = BindingContext as ProductsViewModels;
            vm.RemoveCommand.Execute(product);
        }
    }

In the ViewModel

 internal class ProductsViewModels
    {
        public ObservableCollection<Products> Products
        {
            get;
            set;
        }
        public Command<Products> RemoveCommand
        {
            get
            {
                return new Command<Products>((Product) => {
                    Products.Remove(Product);
                });
            }
        }
        public ProductsViewModels()
        {
            Products = new ObservableCollection<Products> {
                new Products {
                    Name = "name1",
                        Price = 100
                },
                new Products {
                    Name = "name2",
                        Price = 100
                },
                new Products {
                    Name = "name3",
                        Price = 100
                }
            
            };
        }
    }

友情链接