问题描述
我的项目中有一个 ListView，其中一些元素嵌套在 Grid 内的 ViewCell 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。有没有办法以编程方式将焦点更改为 Entry 事件的下一个 Completed？
解决方法
您可以在列表视图中找到所有条目，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。
XML：
<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>
背后的代码：
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",MATRICULA="MATRICULA2",NOME="NOME2",NOTA="NOTA2",ORDEM="NOTA2",txtNotaID=2},new Info{ Cor=Color.Red,DescricaoSituacao="DescricaoSituacao3",MATRICULA="MATRICULA3",NOME="NOME3",NOTA="NOTA3",ORDEM="NOTA3",txtNotaID=3},new Info{ Cor=Color.Accent,DescricaoSituacao="DescricaoSituacao4",MATRICULA="MATRICULA4",NOME="NOME4",NOTA="NOTA4",ORDEM="NOTA4",txtNotaID=4},new Info{ Cor=Color.Gray,DescricaoSituacao="DescricaoSituacao5",MATRICULA="MATRICULA5",NOME="NOME5",NOTA="NOTA5",ORDEM="NOTA5",txtNotaID=5},new Info{ Cor=Color.DarkRed,DescricaoSituacao="DescricaoSituacao6",MATRICULA="MATRICULA6",NOME="NOME6",NOTA="NOTA6",ORDEM="NOTA6",txtNotaID=6},new Info{ Cor=Color.GreenYellow,DescricaoSituacao="DescricaoSituacao7",MATRICULA="MATRICULA7",NOME="NOME7",NOTA="NOTA7",ORDEM="NOTA7",txtNotaID=7},DescricaoSituacao="DescricaoSituacao8",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; }
}
}
在 ListView 中，您可以在 TwoWay 模式下绑定 SelectedItemIndex 和 SelectedItem。因此，如果 selectedItem 已完成，您可以在您的代码隐藏/viewModel 中增加 SelectedItemIndex。