这个问题类似于Excel,比如 Wpf itemscontrol 中的拖动选择,但我想在 DataGrid 中进行,而不是在 ListBox 中进行。
我正在尝试使 WPF DataGrid 中的选择矩形看起来像 Excel 中的矩形,包括右下角的黑色小方块,并且在每个选定的单元格周围没有边框。有人会在 WPF DataGrid 中有这样的工作示例吗?
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1 回答
2
首先,您必须使用此答案中描述的方法隐藏焦点单元格的边框:
<DataGrid.CellStyle>
<Style TargetType="DataGridCell">
<Setter Property="FocusVisualStyle" Value="{x:Null}"/>
</Style>
</DataGrid.CellStyle>
然后,您需要使用OnSelectedCellsChanged
事件DataGrid
来添加/删除将绘制选择矩形的装饰器。对于填充句柄,您可以使用 a Thumb
,它为您处理拖放内容:
void DataGrid_OnSelectedCellsChanged(object sender, SelectedCellsChangedEventArgs e)
{
var datagrid = (System.Windows.Controls.DataGrid)sender;
AdornerLayer adornerLayer = AdornerLayer.GetAdornerLayer(datagrid);
if (datagrid.SelectedCells.Any())
{
DataGridCellInfo firstCellInfo = datagrid.SelectedCells.First();
FrameworkElement firstElt = firstCellInfo.Column.GetCellContent(firstCellInfo.Item);
DataGridCellInfo lastCellInfo = datagrid.SelectedCells.Last();
FrameworkElement lastElt = lastCellInfo.Column.GetCellContent(lastCellInfo.Item);
if (firstElt != null && lastElt != null)
{
var firstcell = (DataGridCell)firstElt.Parent;
var lastCell = (DataGridCell) lastElt.Parent;
Point topLeft = datagrid.PointFromScreen(firstcell.PointToScreen(new Point(0, 0)));
Point bottomRight = datagrid.PointFromScreen(lastCell.PointToScreen(new Point(lastCell.ActualWidth, lastCell.ActualHeight)));
var rect = new Rect(topLeft, bottomRight);
if (fillHandleAdorner == null)
{
fillHandleAdorner = new FillHandleAdorner(datagrid, rect);
adornerLayer.Add(fillHandleAdorner);
}
else
fillHandleAdorner.Rect = rect;
}
}
else
{
adornerLayer.Remove(fillHandleAdorner);
fillHandleAdorner = null;
}
}
FillHandleAdorner 类的代码:
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
namespace DataGrid
{
internal class FillHandleAdorner : Adorner
{
const int SIZE = 5;
Rect rect;
readonly Thumb thumb;
readonly VisualCollection visualChildren;
Point mousePosition;
System.Windows.Controls.DataGrid dataGrid;
public Rect Rect
{
get { return rect; }
set
{
rect = value;
UpdateThumbPos(rect);
mousePosition = rect.BottomRight;
InvalidateVisual();
}
}
public FillHandleAdorner(UIElement adornedElement, Rect rect)
: base(adornedElement)
{
dataGrid = (System.Windows.Controls.DataGrid)adornedElement;
Rect = rect;
visualChildren = new VisualCollection(this);
var border = new FrameworkElementFactory(typeof(Border));
border.SetValue(Border.BackgroundProperty, Brushes.Black);
thumb = new Thumb
{
Cursor = Cursors.Cross,
Background = new SolidColorBrush(Colors.Black),
Height = SIZE,
Template = new ControlTemplate(typeof(Thumb)) { VisualTree = border },
Width = SIZE
};
visualChildren.Add(thumb);
UpdateThumbPos(rect);
thumb.DragDelta += thumb_DragDelta;
}
void UpdateThumbPos(Rect rect)
{
if (thumb == null) return;
mousePosition = rect.BottomRight;
mousePosition.Offset(-SIZE/2 - 1, -SIZE/2 - 1);
thumb.Arrange(new Rect(mousePosition, new Size(SIZE, SIZE)));
}
void thumb_DragDelta(object sender, DragDeltaEventArgs e)
{
mousePosition.Offset(e.HorizontalChange, e.VerticalChange);
IInputElement inputElt = dataGrid.InputHitTest(mousePosition);
var tb = inputElt as TextBlock;
if (tb == null) return;
Point bottomRight = dataGrid.PointFromScreen(tb.PointToScreen(new Point(tb.ActualWidth + 1, tb.ActualHeight + 1)));
Rect = new Rect(rect.TopLeft, bottomRight);
}
protected override int VisualChildrenCount
{
get { return visualChildren.Count; }
}
protected override Visual GetVisualChild(int index)
{
return visualChildren[index];
}
protected override void OnRender(DrawingContext drawingContext)
{
base.OnRender(drawingContext);
var blackSolidBrush = new SolidColorBrush(Colors.Black);
var pen = new Pen(blackSolidBrush, 3);
pen.Freeze();
double halfPenWidth = pen.Thickness / 2;
Rect rangeBorderRect = rect;
rangeBorderRect.Offset(-1, -1);
GuidelineSet guidelines = new GuidelineSet();
guidelines.GuidelinesX.Add(rangeBorderRect.Left + halfPenWidth);
guidelines.GuidelinesX.Add(rangeBorderRect.Right + halfPenWidth);
guidelines.GuidelinesY.Add(rangeBorderRect.Top + halfPenWidth);
guidelines.GuidelinesY.Add(rangeBorderRect.Bottom + halfPenWidth);
Point p1 = rangeBorderRect.BottomRight;
p1.Offset(0, -4);
guidelines.GuidelinesY.Add(p1.Y + halfPenWidth);
Point p2 = rangeBorderRect.BottomRight;
p2.Offset(-4, 0);
guidelines.GuidelinesX.Add(p2.X + halfPenWidth);
drawingContext.PushGuidelineSet(guidelines);
var geometry = new StreamGeometry();
using (StreamGeometryContext ctx = geometry.Open())
{
ctx.BeginFigure(p1, true, false);
ctx.LineTo(rangeBorderRect.TopRight, true, false);
ctx.LineTo(rangeBorderRect.TopLeft, true, false);
ctx.LineTo(rangeBorderRect.BottomLeft, true, false);
ctx.LineTo(p2, true, false);
}
geometry.Freeze();
drawingContext.DrawGeometry(null, pen, geometry);
drawingContext.Pop();
}
}
}
代码不完整,因为它用于尚未启动的项目,但它应该可以帮助您启动。
于 2015-01-17T09:36:48.780 回答