[英]Making a control invisible when its out of bounds of a parent control? in WPF
[英]Drag User Control, but keep it inside the bounds of its parent in WPF
我有一個用戶控件,我在網格內拖動。 Z-Index設置得相當高,以便我可以將它保持在其他孩子之上。 拖動控件可以很好地工作,但如果用戶想要將控件移出網格外,它將允許它。
private System.Windows.Point _anchorPoint;
private System.Windows.Point _currentPoint;
private bool _isInDrag;
private void UserControl_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
var element = sender as FrameworkElement;
_anchorPoint = e.GetPosition(null);
if (element != null) element.CaptureMouse();
_isInDrag = true;
e.Handled = true;
}
private void UserControl_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
if (!_isInDrag) return;
var element = sender as FrameworkElement;
if (element != null) element.ReleaseMouseCapture();
_isInDrag = false;
e.Handled = true;
}
private void UserControl_MouseMove(object sender, MouseEventArgs e)
{
if (!_isInDrag) return;
_currentPoint = e.GetPosition(null);
UIElement container = VisualTreeHelper.GetParent(_parentGrid) as UIElement;
System.Windows.Point relativeLocation = _parentGrid.TranslatePoint(new System.Windows.Point(0, 0), container);
if (_currentPoint.X > relativeLocation.X) return;
if(_currentPoint.Y >= relativeLocation.Y)return;
_transform.X += _currentPoint.X - _anchorPoint.X;
_transform.Y += (_currentPoint.Y - _anchorPoint.Y);
RenderTransform = _transform;
_anchorPoint = _currentPoint;
}
“relativeLocation”始終為0x0,因此不起作用。 任何想法將不勝感激。
*注意:我知道如果我將UserControl更改為Window,它將減輕我遇到的所有問題。 但說實話,這種方式看起來很棒,而且我真的不想讓窗戶混亂。 該系統打開為儀表板,消耗用戶的整個窗口(在單獨的窗口上打開)。 所以當你在這里打開一個窗口時,它不會向右流動。
我認為你不需要relativeLocation。 不過,數學可能有點煩人。 嘗試這種方法,我測試時效果很好:
private void UserControl_MouseMove(object sender, MouseEventArgs e)
{
if (!_isInDrag) return;
_currentPoint = e.GetPosition(null);
//This is the change to the position that we want to apply
Point delta = new Point();
delta.X = _currentPoint.X - _anchorPoint.X;
delta.Y = _currentPoint.Y - _anchorPoint.Y;
//Calculate user control edges
var leftEdge = Margin.Left + _transform.X + delta.X;
var topEdge = Margin.Top + _transform.Y + delta.Y;
var rightEdge = Width + Margin.Left + _transform.X + delta.X;
var bottomEdge = Height + Margin.Top + _transform.Y + delta.Y;
//Set the delta to 0 if it goes over _parentGrid edges
if (leftEdge < 0) delta.X = 0;
if (topEdge < 0) delta.Y = 0;
if (rightEdge > _parentGrid.Width) delta.X = 0;
if (bottomEdge > _parentGrid.Height) delta.Y = 0;
//Apply the delta to the user control
_transform.X += delta.X;
_transform.Y += delta.Y;
RenderTransform = _transform;
_anchorPoint = _currentPoint;
}
這是一個開始:
Point position = _parentGrid.PointToScreen(new Point(0, 0));
PresentationSource source = PresentationSource.FromVisual(_parentGrid);
position = source.CompositionTarget.TransformFromDevice.Transform(position);
現在您擁有父網格的屏幕坐標。 對Transform()
的調用很重要,因為它會將像素轉換為與WPF設備無關的像素,與系統DPI設置相匹配。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.