如何在 xamarin 的 sqlite 中删除集合视图中的一个单元格和行的删除按钮？

Question

如何删除集合视图中的单元格和 sqlite 中的行？ 我需要从集合视图中获取主键，但我不知道如何。 我想在每个视图单元格上都有删除按钮。 我最终得到了这个：

public void RemovePlane()
{
    var db = new SQLiteConnection(_dbPath);
    db.Delete<Airplane>();
}

xaml：

<CollectionView x:Name="myCollectionView" Grid.Row="0" SelectedItem="{Binding selectedPlane}">                
    <CollectionView.ItemTemplate>
        <DataTemplate>
            <StackLayout Margin="0">
                <Frame Padding="0" BackgroundColor="#00d2ff" Margin="0, 65, 0, 0" CornerRadius="30">
                    <StackLayout Padding="20">
                        <Label Text="{Binding Airline}" TextColor ="White" FontSize="30" HorizontalOptions="Center"/>
                        <Image Source="{Binding ThumbnailUrl}" HeightRequest="200"/>
                        <Label Text="{Binding Plane, StringFormat='Plane: {0}'}" TextColor ="White" FontSize="15"/>
                        <Label Text="{Binding Airline, StringFormat='Airline: {0}'}" TextColor ="White" FontSize="15"/>
                        <Label Text="{Binding Livery, StringFormat='Livery: {0}'}" TextColor ="White" FontSize="15"/>
                        <Label Text="{Binding Registration, StringFormat='Reg: {0}'}" TextColor ="White" FontSize="15"/>
                        <Label Text="{Binding Airport, StringFormat='Airport: {0}'}" TextColor ="White" FontSize="15"/>
                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*"/>
                                <ColumnDefinition Width="*" />
                            </Grid.ColumnDefinitions>
                            <StackLayout Grid.Column="0">
                                <Label Text="{Binding Date, StringFormat='Date: {0}'}" TextColor ="White" FontSize="15"/>
                                <Label Text="{Binding Comment, StringFormat='Comment: {0}'}" TextColor ="White" FontSize="15"/>
                            </StackLayout>
                            <Button Text="Delete" CornerRadius="30" Margin="10, 0" HeightRequest="20" BackgroundColor="Red" Grid.Column="1" x:Name="deleteButton"/>
                        </Grid>
                    </StackLayout>
                </Frame>
            </StackLayout>
        </DataTemplate>
    </CollectionView.ItemTemplate>
<CollectionView.EmptyView>                    
    <AbsoluteLayout VerticalOptions="CenterAndExpand">
        <Label FontAttributes="Bold" FontSize="30" TextColor="White" HorizontalTextAlignment="Center" Text="No planes to display" AbsoluteLayout.LayoutBounds="0.5, 0.45, 300, 50" AbsoluteLayout.LayoutFlags="PositionProportional"/>                        
        <Button Text="Import Plane" WidthRequest="10" BackgroundColor="#00d2ff" FontSize="30" FontAttributes="Bold" TextColor="White" CornerRadius="30" VerticalOptions="Center" Padding="5" AbsoluteLayout.LayoutBounds="0.5, 0.55, 280, 70" AbsoluteLayout.LayoutFlags="PositionProportional" Clicked="Button_Clicked"/>
    </AbsoluteLayout>                    
</CollectionView.EmptyView>
</CollectionView>

Answer 1

为您的按钮分配一个处理程序

<Button Text="Delete" Clicked="RemovePlane" ... />

在你的处理程序中

public void RemovePlane(object sender, EventArgs args)
{
    var button = (Button)sender;
    var plane = (Airplane)button.BindingContext;

    var db = new SQLiteConnection(_dbPath);
    db.Delete<Airplane>(plane);

    // finally, either refresh your ItemsSource from your db
    // or if you are using an ObservableCollection just remove
    // it from the collection
}

Answer 2

我已经这样做了，当我刷新它时它就可以工作了。 一个问题它删除了整行？ 它可以以某种方式改进吗？

private void deleteButton_Clicked(object sender, EventArgs e)
    {
        var button = (Button)sender;
        var plane = (Airplane)button.BindingContext;

        var db = new SQLiteConnection(_dbPath);
        db.Delete<Airplane>(plane.Id);
    }