网络上充满了类似的问题,我也在SO上搜索过(最接近的:[1],[2],[3])。
到目前为止,我无法相信这个问题是如此丑陋/非平凡。
我有一个DataGridView。我还有其他控件(在这种情况下:在DataGridView的列标题中)。我想支持一个快速的“跳转到网格”命令。这个命令需要将键盘焦点设置到网格,以便用户可以使用箭头键在行之间导航。
在下面的简单测试用例中,您可以轻松选择数据网格中的元素,但似乎没有办法给它键盘焦点。除非在代码后台操作中,即使在那种情况下,似乎也必须绕过一些障碍(参见[2],通过调整单元格容器来设置键盘焦点,因为..从我所知道的所有情况来看,网格和行似乎都不起作用)。
看起来很简单吧?
一些简单的模型:
public class Item
{
public int DayOfMonth { get; set; }
public string Weekday { get; set; }
}
匹配微不足道的视图模型(假设您有一个RelayCommand实现,请参见JumpToGrid的主要部分):
public class MainViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private IList<Item> m_items;
public IList<Item> SampleItems
{
get { return m_items; }
set { SetField(ref m_items, value, () => SampleItems); }
}
private Item m_currentItem;
public Item CurrentItem
{
get { return m_currentItem; }
set { SetField(ref m_currentItem, value, () => CurrentItem); }
}
public ICommand JumpToGridCommand { get; private set; }
public MainViewModel()
{
JumpToGridCommand = new RelayCommand(p => JumpToGrid());
var items = new List<Item>();
var today = DateTime.Now;
for (int i = 1; i <= DateTime.DaysInMonth(today.Year, today.Month); i++ )
{
items.Add(new Item { DayOfMonth = i, Weekday = new DateTime(today.Year, today.Month, i).DayOfWeek.ToString() });
}
SampleItems = items;
}
private void JumpToGrid()
{
// I can change the selection just fine
CurrentItem = SampleItems[0];
// But the keyboard focus is broken, up/down doesn't work as expected
}
protected bool SetField<T>(ref T field, T value, Expression<Func<T>> selectorExpression)
{
if (selectorExpression == null) throw new ArgumentNullException("selectorExpression");
MemberExpression body = selectorExpression.Body as MemberExpression;
if (body == null) throw new ArgumentException("The body must be a member expression");
var fieldName = body.Member.Name;
if (EqualityComparer<T>.Default.Equals(field, value)) return false;
field = value;
OnPropertyChanged(fieldName);
return true;
}
protected void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
简单的视图(除了在加载事件中的“DataContext = new MainViewModel()”之外,代码后台为空):
<Window x:Class="DataGridKeyboardFocus.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:DataGridKeyboardFocus"
Loaded="Window_Loaded"
Title="MainWindow" Height="350" Width="525">
<Grid>
<DataGrid
ColumnWidth="*"
AutoGenerateColumns="False"
Margin="1"
ItemsSource="{Binding SampleItems}"
SelectedItem="{Binding CurrentItem, Mode=TwoWay}"
SelectionUnit="FullRow"
IsReadOnly="True">
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding DayOfMonth}">
<DataGridTextColumn.HeaderTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<TextBlock Text="Some label" />
<TextBox>
<TextBox.InputBindings>
<KeyBinding Modifiers="Control" Key="Tab" Command="{Binding DataContext.JumpToGridCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:MainWindow}}}" />
</TextBox.InputBindings>
</TextBox>
</StackPanel>
</DataTemplate>
</DataGridTextColumn.HeaderTemplate>
</DataGridTextColumn>
<DataGridTextColumn Binding="{Binding Weekday}">
<DataGridTextColumn.HeaderTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<TextBlock Text="Another label" />
<TextBox>
<TextBox.InputBindings>
<KeyBinding Modifiers="Control" Key="Tab" Command="{Binding DataContext.JumpToGridCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:MainWindow}}}" />
</TextBox.InputBindings>
</TextBox>
</StackPanel>
</DataTemplate>
</DataGridTextColumn.HeaderTemplate>
</DataGridTextColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
1: WPF中的键盘焦点与逻辑焦点 2: 将键盘焦点设置到DataGrid 3: WPF:无法控制键盘焦点
GotKeyboardFocus
/LostKeyboardFocus
事件(以及逻辑焦点变体)来记录焦点变化时的消息。如果我调用Keyboard.Focus()
,我可以看到焦点被设置,但是当我按下箭头键时,焦点丢失并且显然移动到最右边的菜单项,因为该菜单会打开。 - fadden