在 Completed 事件上关注 ListView 中的下一个条目

Question

我的项目中有一个 ListView，其中一些元素嵌套在 ViewCell 中的 Grid 中。其中之一是条目：

    <ListView x:Name="NotasListView" ItemsSource="{Binding Avaliacoes}" 
                          HasUnevenRows="True" 
                          IsRefreshing="{Binding Source={x:Reference NotasView}, Path=IsBusy}}" >
                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <ViewCell>
                                <ViewCell.View>
                                    <Grid Padding="4">
                                        <Grid.ColumnDefinitions>
                                            <ColumnDefinition Width="20"/>
                                            <ColumnDefinition Width="60"/>
                                            <ColumnDefinition Width="170"/>
                                            <ColumnDefinition Width="70"/>
                                        </Grid.ColumnDefinitions>

                                        <Label Grid.Column="0" x:Name="lblOrdem" Text="{Binding ORDEM}" FontSize="12" Margin="1,5" TextColor="{Binding Cor}"></Label>
                                        <Label Grid.Column="1" x:Name="lblMatricula" Text="{Binding MATRICULA}" FontSize="12" Margin="7,5" TextColor="{Binding Cor}"></Label>
                                        <StackLayout   Grid.Column="2">
                                            <Label x:Name="lblNome" Text="{Binding NOME}" FontSize="12" Margin="6,1" TextColor="{Binding Cor}"></Label>
                                            <Label x:Name="lblSituacao" Text="{Binding DescricaoSituacao}" FontSize="12" Margin="6,1" TextColor="{Binding Cor}" IsVisible="{Binding IsVisible}"></Label>
                                        </StackLayout>
                                        <Entry Grid.Column="3" Keyboard="Numeric" x:Name="txtNota" FontAttributes="Bold" 
                                               HorizontalOptions="FillAndExpand" 
                                               HorizontalTextAlignment="Center" 
                                               Margin="7,1" FontSize="14" 
                                               Text="{Binding NOTA}" 
                                               IsEnabled="{Binding IsEnabled}"
                                               Completed="txtNota_Completed">
                                            <Entry.Behaviors>
                                                <behavior:NotaBehavior x:Name="NotaBehavior"  />
                                            </Entry.Behaviors>
                                        </Entry>
                                    </Grid>
                                </ViewCell.View>
                            </ViewCell>
                        </DataTemplate>
                    </ListView.ItemTemplate>
                </ListView>

如您所见，列表内容是动态的。有什么方法可以通过编程将焦点更改为 Completed 事件中的下一个 Entry？

Answer 1

您可以找到列表视图中的所有条目，获取当前条目的索引，然后将焦点设置到下一个条目。我使用 AutomationId 来获取索引。

Xaml:

  <ListView
    x:Name="NotasListView"
    HasUnevenRows="True"
    ItemsSource="{Binding Avaliacoes}">
    <ListView.ItemTemplate>
        <DataTemplate>
            <ViewCell>
                <ViewCell.View>
                    <Grid Padding="4">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="20" />
                            <ColumnDefinition Width="60" />
                            <ColumnDefinition Width="170" />
                            <ColumnDefinition Width="70" />
                        </Grid.ColumnDefinitions>

                        <Label
                            x:Name="lblOrdem"
                            Grid.Column="0"
                            Margin="1,5"
                            FontSize="12"
                            Text="{Binding ORDEM}"
                            TextColor="{Binding Cor}" />
                        <Label
                            x:Name="lblMatricula"
                            Grid.Column="1"
                            Margin="7,5"
                            FontSize="12"
                            Text="{Binding MATRICULA}"
                            TextColor="{Binding Cor}" />
                        <StackLayout Grid.Column="2">
                            <Label
                                x:Name="lblNome"
                                Margin="6,1"
                                FontSize="12"
                                Text="{Binding NOME}"
                                TextColor="{Binding Cor}" />
                            <Label
                                x:Name="lblSituacao"
                                Margin="6,1"
                                FontSize="12"
                                IsVisible="{Binding IsVisible}"
                                Text="{Binding DescricaoSituacao}"
                                TextColor="{Binding Cor}" />
                        </StackLayout>
                        <Entry
                            x:Name="txtNota"
                            Grid.Column="3"
                            Margin="7,1"
                            AutomationId="{Binding txtNotaID}"
                            Completed="txtNota_Completed"
                            FontAttributes="Bold"
                            FontSize="14"
                            HorizontalOptions="FillAndExpand"
                            HorizontalTextAlignment="Center"
                            IsEnabled="{Binding IsEnabled}"
                            Keyboard="Numeric"
                            Text="{Binding NOTA}">
                            <!--<Entry.Behaviors>
                                <behavior:NotaBehavior x:Name="NotaBehavior"  />
                            </Entry.Behaviors>-->
                        </Entry>
                    </Grid>
                </ViewCell.View>
            </ViewCell>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

后面的代码：

    public partial class MainPage : ContentPage
    {
    public ObservableCollection<Info> Avaliacoes { get; set; }

    List<Cell> list { get; set; }

    public MainPage()
    {
        InitializeComponent();
        //var listView = FindByName<ListView>("NotasListView")


        Avaliacoes = new ObservableCollection<Info>()
        {
            new Info{ Cor=Color.Accent, DescricaoSituacao="DescricaoSituacao1", IsEnabled=true, IsVisible=true, MATRICULA="MATRICULA1", NOME="NOME1",  NOTA="NOTA1", ORDEM="NOTA1" ,txtNotaID=1},
            new Info{ Cor=Color.AntiqueWhite, DescricaoSituacao="DescricaoSituacao2", IsEnabled=true, IsVisible=true, MATRICULA="MATRICULA2", NOME="NOME2",  NOTA="NOTA2", ORDEM="NOTA2",txtNotaID=2},
            new Info{ Cor=Color.Red, DescricaoSituacao="DescricaoSituacao3", IsEnabled=true, IsVisible=true, MATRICULA="MATRICULA3", NOME="NOME3",  NOTA="NOTA3", ORDEM="NOTA3",txtNotaID=3},
            new Info{ Cor=Color.Accent, DescricaoSituacao="DescricaoSituacao4", IsEnabled=true, IsVisible=true, MATRICULA="MATRICULA4", NOME="NOME4",  NOTA="NOTA4", ORDEM="NOTA4",txtNotaID=4},
            new Info{ Cor=Color.Gray, DescricaoSituacao="DescricaoSituacao5", IsEnabled=true, IsVisible=true, MATRICULA="MATRICULA5", NOME="NOME5",  NOTA="NOTA5", ORDEM="NOTA5",txtNotaID=5},
            new Info{ Cor=Color.DarkRed, DescricaoSituacao="DescricaoSituacao6", IsEnabled=true, IsVisible=true, MATRICULA="MATRICULA6", NOME="NOME6",  NOTA="NOTA6", ORDEM="NOTA6",txtNotaID=6},
            new Info{ Cor=Color.GreenYellow, DescricaoSituacao="DescricaoSituacao7", IsEnabled=true, IsVisible=true, MATRICULA="MATRICULA7", NOME="NOME7",  NOTA="NOTA7", ORDEM="NOTA7",txtNotaID=7},
            new Info{ Cor=Color.Accent, DescricaoSituacao="DescricaoSituacao8", IsEnabled=true, IsVisible=true, MATRICULA="MATRICULA8", NOME="NOME8",  NOTA="NOTA8", ORDEM="NOTA8",txtNotaID=8},
        };
        this.BindingContext = this;




    }

    private void txtNota_Completed(object sender, EventArgs e)
    {
        var entry = sender as Entry; // .. and check for null

        var list = NotasListView.TemplatedItems.ToList();

        var index = Convert.ToInt32(entry.AutomationId)-1;
        var nextIndex = (index + 1) >= list.Count ? 0 : index + 1;

        foreach (ViewCell item in list)
        {
            var elements = (item.View as Grid).Children;

        }
        var next = ((list[nextIndex] as ViewCell).View as Grid).Children.ElementAt(3);
        next?.Focus();      

    }
}
public class Info
{
    public string ORDEM { get; set; }
    public string MATRICULA { get; set; }
    public Color Cor { get; set; }
    public string NOME { get; set; }
    public string DescricaoSituacao { get; set; }
    public bool IsVisible { get; set; }
    public bool IsEnabled { get; set; }
    public string NOTA { get; set; }
    public int txtNotaID { get; set; }
}

}

Answer 2

在 ListView 中，您可以在 TwoWay 模式下绑定 SelectedItemIndex 和 SelectedItem。因此，如果 selectedItem 已完成，您可以在代码中增加 SelectedItemIndex behind/viewModel.

在 Completed 事件上关注 ListView 中的下一个条目

Focus on next entry in ListView on Completed event

xaml

datatemplate

xamarin

xamarin.forms

xamarin.forms.listview