我有一个自定义装饰器，在选择它们时添加到控件中。问题是，我还注册了一个自定义全局事件，以便在聚焦时自动选择文本框中的所有文本。
我遇到的问题是，当我尝试在带有选定文字的文本框中使用它时，我的装饰工具无效。出于某种原因，它会尝试拖动所选文本。奇怪的是我可以拖动选定的文本然后在完成删除后我可以使用我的装饰。我不知道为什么或如何解决它。
我尝试取消单个文本框上的拖动命令，但这也会阻止装饰工作。
有没有办法可以让装饰者比所选文字更优先？
这是我的自定义装饰器
public class DraggingAdorner : Adorner
{
Thumb draggingIcon = null;
Thumb resizeThumb = null;
Border border = null;
VisualCollection visualChildren;
public DraggingAdorner(UIElement adornedElement)
: base(adornedElement)
{
visualChildren = new VisualCollection(this);
BuildBorder();
BuildDraggingIcon();
BuildResizer();
draggingIcon.DragDelta += DraggingIcon_DragDelta;
resizeThumb.DragDelta += Resize;
resizeThumb.MouseDoubleClick += ResizeThumb_MouseDoubleClick;
}
private void ResizeThumb_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
FrameworkElement adornedElement = this.AdornedElement as FrameworkElement;
Thumb hitThumb = sender as Thumb;
if (adornedElement == null || hitThumb == null) return;
FrameworkElement parentElement = adornedElement.Parent as FrameworkElement;
var tb = adornedElement as TextBox;
if (tb == null) return;
tb.Height = Double.NaN;
tb.Width = Double.NaN;
e.Handled = true;
}
private void BuildBorder()
{
if (border != null) return;
border = new Border();
border.BorderBrush = new SolidColorBrush(Colors.Black);
border.BorderThickness = new Thickness(1);
border.Opacity = .5;
visualChildren.Add(border);
}
private void BuildDraggingIcon()
{
if (draggingIcon != null) return;
draggingIcon = new Thumb();
draggingIcon.Cursor = Cursors.Hand;
draggingIcon.Height = draggingIcon.Width = 12;
draggingIcon.Opacity = 0.40;
draggingIcon.Background = new SolidColorBrush(Colors.Black);
visualChildren.Add(draggingIcon);
}
private void BuildResizer()
{
if (resizeThumb != null) return;
resizeThumb = new Thumb();
// Set some arbitrary visual characteristics.
resizeThumb.Cursor = Cursors.ScrollAll;
resizeThumb.Height = resizeThumb.Width = 10;
resizeThumb.Opacity = 0.40;
resizeThumb.Background = new SolidColorBrush(Colors.Red);
visualChildren.Add(resizeThumb);
}
private void DraggingIcon_DragDelta(object sender, DragDeltaEventArgs e)
{
FrameworkElement adornedElement = this.AdornedElement as FrameworkElement;
Thumb hitThumb = sender as Thumb;
if (adornedElement == null || hitThumb == null) return;
FrameworkElement parentElement = adornedElement.Parent as FrameworkElement;
var left = e.HorizontalChange + Canvas.GetLeft(adornedElement);
if (left <= 0)
{
left = 1;
}
else if (left + adornedElement.ActualWidth >= parentElement.ActualWidth)
{
left = parentElement.ActualWidth - adornedElement.ActualWidth - 1;
}
var top = e.VerticalChange + Canvas.GetTop(adornedElement);
if (top <= 0)
{
top = 1;
}
else if (top + adornedElement.ActualHeight >= parentElement.ActualHeight)
{
top = parentElement.ActualHeight - adornedElement.ActualHeight - 1;
}
Canvas.SetLeft(adornedElement, left);
Canvas.SetTop(adornedElement, top);
}
// Handler for resizing from the bottom-right.
private void Resize(object sender, DragDeltaEventArgs e)
{
FrameworkElement adornedElement = this.AdornedElement as FrameworkElement;
Thumb hitThumb = sender as Thumb;
if (adornedElement == null || hitThumb == null) return;
FrameworkElement parentElement = adornedElement.Parent as FrameworkElement;
// Ensure that the Width and Height are properly initialized after the resize.
EnforceSize(adornedElement);
var left = Canvas.GetLeft(adornedElement);
var top = Canvas.GetTop(adornedElement);
var newWidth = Math.Max(adornedElement.Width + e.HorizontalChange, hitThumb.DesiredSize.Width);
var newHeight = Math.Max(e.VerticalChange + adornedElement.Height, hitThumb.DesiredSize.Height);
if (left + newWidth >= parentElement.ActualWidth)
{
newWidth = parentElement.ActualWidth - left;
}
if (top + newHeight >= parentElement.ActualHeight)
{
newHeight = parentElement.ActualHeight - top;
}
adornedElement.Width = newWidth;
adornedElement.Height = newHeight;
}
private void EnforceSize(FrameworkElement adornedElement)
{
if (adornedElement.Width.Equals(Double.NaN))
adornedElement.Width = adornedElement.DesiredSize.Width;
if (adornedElement.Height.Equals(Double.NaN))
adornedElement.Height = adornedElement.DesiredSize.Height;
FrameworkElement parent = adornedElement.Parent as FrameworkElement;
if (parent != null)
{
adornedElement.MaxHeight = parent.ActualHeight;
adornedElement.MaxWidth = parent.ActualWidth;
}
}
protected override Size ArrangeOverride(Size finalSize)
{
double desiredWidth = AdornedElement.DesiredSize.Width;
double desiredHeight = AdornedElement.DesiredSize.Height;
double adornerWidth = this.DesiredSize.Width;
double adornerHeight = this.DesiredSize.Height;
draggingIcon.Arrange(new Rect(-adornerWidth / 2, -adornerHeight / 2, adornerWidth, adornerHeight));
resizeThumb.Arrange(new Rect(desiredWidth - adornerWidth / 2, desiredHeight - adornerHeight / 2, adornerWidth, adornerHeight));
border.Arrange(new Rect(0, 0, adornerWidth, adornerHeight));
return finalSize;
}
protected override int VisualChildrenCount { get { return visualChildren.Count; } }
protected override Visual GetVisualChild(int index) { return visualChildren[index]; }
}
以下是我应用装配工具的代码
private void OnPreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
e.Handled = AdornSelectedElement(sender as UIElement);
}
private bool AdornSelectedElement(UIElement element)
{
if (element == null) return false;
RemoveSelectedElement();
if (Canvas.GetLeft(element) < 0)
Canvas.SetLeft(element, 1);
var aLayer = AdornerLayer.GetAdornerLayer(element);
if ((aLayer.GetAdorners(element)?.Length ?? 0) > 0) return false;
aLayer.Add(new DraggingAdorner(element));
selectedElement = element;
return true;
}
private void RemoveSelectedElement()
{
if (selectedElement == null) return;
var aLayer = AdornerLayer.GetAdornerLayer(selectedElement);
if ((aLayer.GetAdorners(selectedElement)?.Length ?? 0) < 1) return;
aLayer.Remove(aLayer.GetAdorners(selectedElement)[0]);
selectedElement = null;
}
这是我的全局事件处理程序
protected override void OnStartup(StartupEventArgs e)
{
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.GotKeyboardFocusEvent, new RoutedEventHandler(OnTextBoxFocus));
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.GotFocusEvent, new RoutedEventHandler(OnTextBoxFocus));
base.OnStartup(e);
}
private void OnTextBoxFocus(object sender, RoutedEventArgs e)
{
var tb = sender as System.Windows.Controls.TextBox;
if (tb == null) return;
if (!String.IsNullOrWhiteSpace(tb.Text))
tb.SelectAll();
}
最后，这里是取消所选文本内部拖动的代码
DataObject.AddCopyingHandler(tb, (s, e) =>
{
if (e.IsDragDrop)
{
e.CancelCommand();
}
});
我将非常乐意添加可能需要的更多代码。
编辑：我认为这不仅仅是因为TextBox中的选定文本。我觉得我的装饰师和文本框有些奇怪，但我不确定是什么。我有一个自定义的图像控件，工作正常。
第二次编辑：选择文本框后，看起来我实际上根本无法做任何事情（IE关闭主窗口，点击其他控件等）。出于某种原因，有一些奇怪的事情发生在必须不正确地处理选择并且它不会退出这种奇怪的拖动文本模式。我需要拖放文本，之后我可以再做任何我想做的事。
答案 0 :(得分：0)
我有点想出了这个问题。原来这个方法
private void OnPreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
e.Handled = AdornSelectedElement(sender as UIElement);
}
导致文本框出现问题。我有一个自定义图像控件，需要e.Handled设置为true才能使此选项正常启动，但在TextBoxes上，这会导致奇怪的选定文本拖动问题。我改变了
return true;
在我的
结束时AdornSelectedElement
例程阅读
return element is ImageBox;
并修复了它。如果有人知道为什么我可以提供自定义控件的Xaml，我们可以讨论为什么会发生这种情况。
谢谢！