我使用了一个拖动装饰器来克隆我的标签图像（拖动目标），但是现在我无法将我的标签放到我的文本框中，
这是我使用的代码（你可能会看到有 previewdragover ，我在 previewdragover 中写了 e.Handled = true 但没有帮助）我还将 tbox.AllowDrop 设置为 true ：
文本框 ：
tbox.PreviewDrop += new DragEventHandler(tbox_PreviewDrop);
tbox.PreviewDragOver += new DragEventHandler(tbox_PreviewDragOver);
文本框的处理程序：
protected void tbox_PreviewDrop(object sender, DragEventArgs e)
{
(sender as TextBox).Text = string.Empty; // Empty the textbox from previous answer.
(sender as TextBox).Background = Brushes.White;
e.Handled = true;
}
标签（拖动目标）：
Label lbl = new Label();
lbl.Content = s;
lbl.Width = Double.NaN;
lbl.Height = 40;
lbl.FontSize = 19;
lbl.MouseDown += new MouseButtonEventHandler(lbl_MouseDown);
lbl.MouseMove += new MouseEventHandler(lbl_MouseMove);
lbl.GiveFeedback += new GiveFeedbackEventHandler(lbl_GiveFeedback);
lbl.MouseUp += new MouseButtonEventHandler(lbl_MouseUp);
wrapPanel2.Children.Add(lbl);
标签的处理程序：
private void lbl_MouseUp(object sender, MouseButtonEventArgs e)
{
Mouse.OverrideCursor = Cursors.Arrow;
}
private void lbl_MouseDown(object sender, MouseButtonEventArgs e)
{
startPoint = e.GetPosition(this);
}
private void lbl_MouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
var source = sender as UIElement;
Label lbl = sender as Label;
Point current = e.GetPosition(this);
Vector diff = startPoint - current;
if (Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance ||
Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance)
{
adorner = new DragAdorner(lbl, e.GetPosition(lbl));
AdornerLayer.GetAdornerLayer(lbl).Add(adorner);
var dragData = new DataObject(this);
DragDrop.DoDragDrop(source, dragData, DragDropEffects.Copy);
AdornerLayer.GetAdornerLayer(lbl).Remove(adorner);
}
startPoint = current;
}
}
private void lbl_GiveFeedback(object sender, GiveFeedbackEventArgs e)
{
if (adorner != null)
{
Label lbl = sender as Label;
var pos = lbl.PointFromScreen(GetMousePosition());
adorner.UpdatePosition(pos);
}
}
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool GetCursorPos(ref Win32Point pt);
[StructLayout(LayoutKind.Sequential)]
internal struct Win32Point
{
public Int32 X;
public Int32 Y;
};
public static Point GetMousePosition()
{
Win32Point w32Mouse = new Win32Point();
GetCursorPos(ref w32Mouse);
return new Point(w32Mouse.X, w32Mouse.Y);
}
private Point startPoint;
private DragAdorner adorner;
现在我可以用光标后面的标签拖动标签，但我不能将它们放在任何文本框中。
- - -编辑 - - - - - -
我已经为这样的文本框放置了一个拖动器：
private void tbox_PreviewDragEnter(object sender, DragEventArgs e)
{
if (sender == e.Source)
{
e.Effects = DragDropEffects.None;
}
}
仍然无法正常工作。
我将在此处添加我使用过的 DragAdorner.cs（我从一些中文网站获得）：
public class DragAdorner : Adorner {
public DragAdorner(UIElement adornedElement, Point offset)
: base(adornedElement) {
this.offset = offset;
vbrush = new VisualBrush(AdornedElement);
vbrush.Opacity = .7;
}
public void UpdatePosition(Point location) {
this.location = location;
this.InvalidateVisual();
}
protected override void OnRender(DrawingContext dc) {
var p = location;
p.Offset(-offset.X, -offset.Y);
dc.DrawRectangle(vbrush, null, new Rect(p, this.RenderSize));
}
private Brush vbrush;
private Point location;
private Point offset;