我希望将行号放入 WPF 4 DataGrid 的 RowHeader 中,以便它有一个类似于 Excel 的列用于显示 DataGrid 的行号。
我在网上看到的解决方案建议向业务对象添加索引字段。 这并不是一个真正的选择,因为 DataGrid 将被大量使用,并且我们不想不断跟踪这些索引字段的更改。
非常感谢
一种方法是将它们添加到
DataGrid
的 LoadingRow 事件中。
<DataGrid Name="DataGrid" LoadingRow="DataGrid_LoadingRow" ... />
void DataGrid_LoadingRow(object sender, DataGridRowEventArgs e)
{
// Adding 1 to make the row count start at 1 instead of 0
// as pointed out by daub815
e.Row.Header = (e.Row.GetIndex() + 1).ToString();
}
更新
为了使其能够与 WPF Toolkit 中的 .NET 3.5 DataGrid 一起使用,需要进行一些修改。使用虚拟化时,索引仍然可以正确生成,但输出失败。对
RowHeaderTemplate
的以下修改修复了此问题
<toolkit:DataGrid LoadingRow="DataGrid_LoadingRow">
<toolkit:DataGrid.RowHeaderTemplate>
<DataTemplate>
<TextBlock Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type toolkit:DataGridRow}},
Path=Header}"/>
</DataTemplate>
</toolkit:DataGrid.RowHeaderTemplate>
</toolkit:DataGrid>
编辑2012-07-05
如果从源列表中添加或删除项目,则数字会不同步,直到滚动列表,从而再次调用
LoadingRow
。解决这个问题有点复杂,我现在能想到的最好的解决方案是保留上面的LoadingRow
解决方案以及
dataGrid.ItemContainerGenerator.ItemsChanged
DataGridRows
DataGridRow
这是执行此操作的附加行为。像这样使用
<DataGrid ItemsSource="{Binding ...}"
behaviors:DataGridBehavior.DisplayRowNumber="True">
显示行号
public class DataGridBehavior
{
#region DisplayRowNumber
public static DependencyProperty DisplayRowNumberProperty =
DependencyProperty.RegisterAttached("DisplayRowNumber",
typeof(bool),
typeof(DataGridBehavior),
new FrameworkPropertyMetadata(false, OnDisplayRowNumberChanged));
public static bool GetDisplayRowNumber(DependencyObject target)
{
return (bool)target.GetValue(DisplayRowNumberProperty);
}
public static void SetDisplayRowNumber(DependencyObject target, bool value)
{
target.SetValue(DisplayRowNumberProperty, value);
}
private static void OnDisplayRowNumberChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
DataGrid dataGrid = target as DataGrid;
if ((bool)e.NewValue == true)
{
EventHandler<DataGridRowEventArgs> loadedRowHandler = null;
loadedRowHandler = (object sender, DataGridRowEventArgs ea) =>
{
if (GetDisplayRowNumber(dataGrid) == false)
{
dataGrid.LoadingRow -= loadedRowHandler;
return;
}
ea.Row.Header = ea.Row.GetIndex();
};
dataGrid.LoadingRow += loadedRowHandler;
ItemsChangedEventHandler itemsChangedHandler = null;
itemsChangedHandler = (object sender, ItemsChangedEventArgs ea) =>
{
if (GetDisplayRowNumber(dataGrid) == false)
{
dataGrid.ItemContainerGenerator.ItemsChanged -= itemsChangedHandler;
return;
}
GetVisualChildCollection<DataGridRow>(dataGrid).
ForEach(d => d.Header = d.GetIndex());
};
dataGrid.ItemContainerGenerator.ItemsChanged += itemsChangedHandler;
}
}
#endregion // DisplayRowNumber
#region Get Visuals
private static List<T> GetVisualChildCollection<T>(object parent) where T : Visual
{
List<T> visualCollection = new List<T>();
GetVisualChildCollection(parent as DependencyObject, visualCollection);
return visualCollection;
}
private static void GetVisualChildCollection<T>(DependencyObject parent, List<T> visualCollection) where T : Visual
{
int count = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < count; i++)
{
DependencyObject child = VisualTreeHelper.GetChild(parent, i);
if (child is T)
{
visualCollection.Add(child as T);
}
if (child != null)
{
GetVisualChildCollection(child, visualCollection);
}
}
}
#endregion // Get Visuals
}
编辑:显然滚动会更改索引,因此绑定不会像那样工作......
(看似)干净的模板解决方案:
XAML:
<Window
...
xmlns:local="clr-namespace:Test"
DataContext="{Binding RelativeSource={RelativeSource Mode=Self}}">
<Window.Resources>
<local:RowToIndexConv x:Key="RowToIndexConv"/>
</Window.Resources>
<DataGrid ItemsSource="{Binding GridData}">
<DataGrid.RowHeaderTemplate>
<DataTemplate>
<TextBlock Margin="2" Text="{Binding RelativeSource={RelativeSource AncestorType=DataGridRow}, Converter={StaticResource RowToIndexConv}}"/>
</DataTemplate>
</DataGrid.RowHeaderTemplate>
</DataGrid>
</Window>
转换器:
public class RowToIndexConv : IValueConverter
{
#region IValueConverter Members
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
DataGridRow row = value as DataGridRow;
return row.GetIndex() + 1;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
#endregion
}
如果添加或删除行,所有这些方法都将不起作用。在这种情况下,您应该刷新行索引。看看这个行为:
public static class DataGridBehavior
{
#region RowNumbers property
public static readonly DependencyProperty RowNumbersProperty =
DependencyProperty.RegisterAttached("RowNumbers", typeof (bool), typeof (DataGridBehavior),
new FrameworkPropertyMetadata(false, OnRowNumbersChanged));
private static void OnRowNumbersChanged(DependencyObject source, DependencyPropertyChangedEventArgs args)
{
DataGrid grid = source as DataGrid;
if (grid == null)
return;
if ((bool)args.NewValue)
{
grid.LoadingRow += onGridLoadingRow;
grid.UnloadingRow += onGridUnloadingRow;
}
else
{
grid.LoadingRow -= onGridLoadingRow;
grid.UnloadingRow -= onGridUnloadingRow;
}
}
private static void refreshDataGridRowNumbers(object sender)
{
DataGrid grid = sender as DataGrid;
if (grid == null)
return;
foreach (var item in grid.Items)
{
var row = (DataGridRow)grid.ItemContainerGenerator.ContainerFromItem(item);
if (row != null)
row.Header = row.GetIndex() + 1;
}
}
private static void onGridUnloadingRow(object sender, DataGridRowEventArgs e)
{
refreshDataGridRowNumbers(sender);
}
private static void onGridLoadingRow(object sender, DataGridRowEventArgs e)
{
refreshDataGridRowNumbers(sender);
}
[AttachedPropertyBrowsableForType(typeof(DataGrid))]
public static void SetRowNumbers(DependencyObject element, bool value)
{
element.SetValue(RowNumbersProperty, value);
}
public static bool GetRowNumbers(DependencyObject element)
{
return (bool) element.GetValue(RowNumbersProperty);
}
#endregion
}
@Fredrik Hedblad 的答案对我有用。谢谢!
我添加了另一个属性来获取“偏移”值,以便 DataGrid 可以从 0 或 1(或任何设置的值)开始。
要使用该行为,(注意“b”是命名空间)
<DataGrid ItemsSource="{Binding ...}"
b:DataGridBehavior.DisplayRowNumberOffset="1"
b:DataGridBehavior.DisplayRowNumber="True">
修改后的类:
/// <summary>
/// Collection of DataGrid behavior
/// </summary>
public static class DataGridBehavior
{
#region DisplayRowNumberOffset
/// <summary>
/// Sets the starting value of the row header if enabled
/// </summary>
public static DependencyProperty DisplayRowNumberOffsetProperty =
DependencyProperty.RegisterAttached("DisplayRowNumberOffset",
typeof(int),
typeof(DataGridBehavior),
new FrameworkPropertyMetadata(0, OnDisplayRowNumberOffsetChanged));
public static int GetDisplayRowNumberOffset(DependencyObject target)
{
return (int)target.GetValue(DisplayRowNumberOffsetProperty);
}
public static void SetDisplayRowNumberOffset(DependencyObject target, int value)
{
target.SetValue(DisplayRowNumberOffsetProperty, value);
}
private static void OnDisplayRowNumberOffsetChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
DataGrid dataGrid = target as DataGrid;
int offset = (int)e.NewValue;
if (GetDisplayRowNumber(target))
{
WPFUtil.GetVisualChildCollection<DataGridRow>(dataGrid).
ForEach(d => d.Header = d.GetIndex() + offset);
}
}
#endregion
#region DisplayRowNumber
/// <summary>
/// Enable display of row header automatically
/// </summary>
/// <remarks>
/// Source:
/// </remarks>
public static DependencyProperty DisplayRowNumberProperty =
DependencyProperty.RegisterAttached("DisplayRowNumber",
typeof(bool),
typeof(DataGridBehavior),
new FrameworkPropertyMetadata(false, OnDisplayRowNumberChanged));
public static bool GetDisplayRowNumber(DependencyObject target)
{
return (bool)target.GetValue(DisplayRowNumberProperty);
}
public static void SetDisplayRowNumber(DependencyObject target, bool value)
{
target.SetValue(DisplayRowNumberProperty, value);
}
private static void OnDisplayRowNumberChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
DataGrid dataGrid = target as DataGrid;
if ((bool)e.NewValue == true)
{
int offset = GetDisplayRowNumberOffset(target);
EventHandler<DataGridRowEventArgs> loadedRowHandler = null;
loadedRowHandler = (object sender, DataGridRowEventArgs ea) =>
{
if (GetDisplayRowNumber(dataGrid) == false)
{
dataGrid.LoadingRow -= loadedRowHandler;
return;
}
ea.Row.Header = ea.Row.GetIndex() + offset;
};
dataGrid.LoadingRow += loadedRowHandler;
ItemsChangedEventHandler itemsChangedHandler = null;
itemsChangedHandler = (object sender, ItemsChangedEventArgs ea) =>
{
if (GetDisplayRowNumber(dataGrid) == false)
{
dataGrid.ItemContainerGenerator.ItemsChanged -= itemsChangedHandler;
return;
}
WPFUtil.GetVisualChildCollection<DataGridRow>(dataGrid).
ForEach(d => d.Header = d.GetIndex() + offset);
};
dataGrid.ItemContainerGenerator.ItemsChanged += itemsChangedHandler;
}
}
#endregion // DisplayRowNumber
}
LoadingRowEvent 是这样触发的:
ICollectionView view = CollectionViewSource.GetDefaultView(_dataGrid.ItemsSource);
view.Refresh();
另一个解决方案与上面的答案有些相似,但有一些限制和巨大的优势。
IValueConverter
ItemsSource
的集合,因为需要方法IList
来查找项目的索引。 IndexOf
这里很好。收藏品必须是参考类型。ObservableCollection<T>
的虚拟化类型。特别是默认虚拟化设置有效。因此它可以在相当大的虚拟化网格中正常工作。
首先我们需要一个多值转换器:DataGrid
然后在XAML资源中注册:
public class RowIndexConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
if (values.Length == 2 && values[1] is IList items)
{
int index = items.IndexOf(values[0]);
if (index >= 0)
{
return $"{index + 1}";
}
}
return string.Empty;
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotSupportedException();
}
}
然后使用
<Window.Resources>
<local:RowIndexConverter x:Key="RowIndexConverter"/>
</Window.Resources>
的行标题模板中的转换器:
DataGrid
就是这样。