Question

我正在使用全屏Grid的动态C＃WPF应用程序（在Windows 10上）。控件在运行时动态添加到网格中（在Dictionary<>中管理）我最近添加了代码，使用TranslateTransform（使用鼠标）（也在运行时）沿着网格移动控件（我现在怀疑的可行性）。

有没有办法可以防止控件在移动时重叠或“共享空间”？换句话说，添加某种碰撞检测。我会使用if语句来检查控制边距范围吗？我的移动事件如下所示：

MainWindow.xaml.cs：

public partial class MainWindow : Window
{
     // Orientation variables:
     public bool _isInDrag = false;
     public Dictionary<object, TranslateTransform> PointDict = new Dictionary<object, TranslateTransform();
     public Point _anchorPoint;
     public Point _currentPoint;

     public MainWindow()
     {
          InitializeComponent();
     }

    public static void Control_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        if (_isInDrag)
        {
            var element = sender as FrameworkElement;
            element.ReleaseMouseCapture();
            _isInDrag = false;
            e.Handled = true;
        }           
    }

    public static void Control_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
         var element = sender as FrameworkElement;
         _anchorPoint = e.GetPosition(null);
         element.CaptureMouse();
         _isInDrag = true;
         e.Handled = true;
    }

    public static void Control_MouseMove(object sender, MouseEventArgs e)
    {
        if (_isInDrag)
        {
            _currentPoint = e.GetPosition(null);
            TranslateTransform tt = new TranslateTransform();
            bool isMoved = false;
            if (PointDict.ContainsKey(sender))
            {
                tt = PointDict[sender];
                isMoved = true;
            }
            tt.X += _currentPoint.X - _anchorPoint.X;
            tt.Y += (_currentPoint.Y - _anchorPoint.Y);
            (sender as UIElement).RenderTransform = tt;
            _anchorPoint = _currentPoint;
            if (isMoved)
            {
                PointDict.Remove(sender);
            }
            PointDict.Add(sender, tt);
        }
   }
}

MainWindow.xaml（示例）：

<Window x:Name="MW" x:Class="MyProgram.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:MyProgram"
    mc:Ignorable="d"
    Title="MyProgram" d:DesignHeight="1080" d:DesignWidth="1920" ResizeMode="NoResize" WindowState="Maximized" WindowStyle="None">

    <Grid x:Name="MyGrid" />
        <Image x:Name="Image1" Source="pic.png" Margin="880,862,0,0" Height="164" Width="162" HorizontalAlignment="Left" VerticalAlignment="Top" MouseLeftButtonDown="Control_MouseLeftButtonDown" MouseLeftButtonUp="Control_MouseLeftButtonUp" MouseMove="Control_MouseMove" />
        <TextBox x:Name="Textbox1" Margin="440,560,0,0" HorizontalAlignment="Left" VerticalAlignment="Top" MouseLeftButtonDown="Control_MouseLeftButtonDown" MouseLeftButtonUp="Control_MouseLeftButtonUp" MouseMove="Control_MouseMove" />
</Window>

编辑：使用TranslateTransform移动控件似乎不会更改该控件的边距。不知道为什么。

编辑2：没有太多牵引力。如果有人需要澄清任何事情，请询问。

编辑3：非常确定我不能使用TranslateTransform，因为它不会改变给定控件的边距。还有其他选择吗？

编辑4：为想要复制的人添加了一些“样板”代码。糊。如果您对此有任何疑问，请与我们联系。

Answer 1

TL; DR：Demo from the bottom of this answer

如果要在不向每个控件添加事件处理程序的情况下修改UI，则可以使用Adorners。 Adorners（顾名思义）控件装饰另一个控件以添加其他视觉效果或在您的案例功能中。 Adorners位于AdornerLayer，您可以自行添加或使用每个WPF Window已有的。 AdornerLayer位于所有其他控件之上。

你从未提到当用户在控件重叠时松开鼠标按钮会发生什么，所以如果发生这种情况，我只需将控件重置为原始位置。

此时我通常会解释在移动控件时应该记住什么，但由于您的原始示例甚至包含CaptureMouse人通常会忘记，我认为您将理解代码而无需进一步解释：）< / p>

您可能想要添加/改进的一些事项：

对齐网格功能（像素精确移动对普通用户来说可能有点压倒性）
计算重叠时考虑RenderTransform，LayoutTransform和非矩形形状（如果需要）
将编辑功能（启用，禁用等）移动到单独的控件中并添加专用的AdornerLayer
在编辑模式下停用互动控件（Buttons，TextBoxes，ComboBoxes等）
当用户按 Esc
~~限制移动到父容器的边界~~已完成
将有效 Adorner移至AdornerLayer
让用户一次移动多个控件（通常通过 Ctrl 选择它们）

以前未回答的问题：

您是说在使用TranslateTransform时不再为控件分配边距？

完全没有 - 您可以使用Grid.Row，Grid.Column，Margin，RenderTransform 和 LayoutTransform的组合，但那么确定控件实际显示的位置将是一场噩梦。如果您坚持使用（例如Margin或LayoutTransform），则更容易使用和跟踪。如果您发现自己处于需要多个同时的情况，则必须通过转换(0, 0)和{来确定控件的角来找到实际位置{1}} (ActualWidth, ActualHeight)。相信我，你不想去那里 - 保持简单，坚持其中一个。

下面的代码不是“如何移动东西的圣杯”但它应该让你知道如何做到这一点以及你可以用它做什么（调整大小，旋转，删除控件等）。布局完全基于控件的TransformToAncestor和Left边距。如果您愿意，只要保持一致，就不应该为Top换取所有Margins。

移动装饰工具

LayoutTransforms

<强>用法

using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;

public class MoveAdorner : Adorner
{
    // The parent of the adorned Control, in your case a Grid
    private readonly Panel _parent;
    // Same as "AdornedControl" but as a FrameworkElement
    private readonly FrameworkElement _child;

    // The visual overlay rectangle we can click and drag
    private readonly Rectangle _rect;
    // Our own collection of child elements, in this example only _rect
    private readonly UIElementCollection _visualChildren;

    private bool _down;
    private Point _downPos;
    private Thickness _downMargin;

    private List<Rect> _otherRects;

    protected override int VisualChildrenCount => _visualChildren.Count;

    protected override Visual GetVisualChild(int index)
    {
        return _visualChildren[index];
    }

    public MoveAdorner(FrameworkElement adornedElement) : base(adornedElement)
    {
        _child = adornedElement;
        _parent = adornedElement.Parent as Panel;
        _visualChildren = new UIElementCollection(this,this);
        _rect = new Rectangle
        {
            HorizontalAlignment = HorizontalAlignment.Stretch,
            VerticalAlignment = VerticalAlignment.Stretch,
            StrokeThickness = 1,
        };

        SetColor(Colors.LightGray);

        _rect.MouseLeftButtonDown += RectOnMouseLeftButtonDown;
        _rect.MouseLeftButtonUp += RectOnMouseLeftButtonUp;
        _rect.MouseMove += RectOnMouseMove;

        _visualChildren.Add(_rect);
    }

    private void SetColor(Color color)
    {
        _rect.Fill = new SolidColorBrush(color) {Opacity = 0.3};
        _rect.Stroke = new SolidColorBrush(color) {Opacity = 0.5};
    }

    private void RectOnMouseMove(object sender, MouseEventArgs args)
    {
        if (!_down) return;

        Point pos = args.GetPosition(_parent);
        UpdateMargin(pos);
    }

    private void UpdateMargin(Point pos)
    {
        double deltaX = pos.X - _downPos.X;
        double deltaY = pos.Y - _downPos.Y;

        Thickness newThickness = new Thickness(_downMargin.Left + deltaX, _downMargin.Top + deltaY, 0, 0);

        //Restrict to parent's bounds
        double leftMax = _parent.ActualWidth - _child.ActualWidth;
        double topMax = _parent.ActualHeight - _child.ActualHeight;

        newThickness.Left = Math.Max(0, Math.Min(newThickness.Left, leftMax));
        newThickness.Top = Math.Max(0, Math.Min(newThickness.Top, topMax));

        _child.Margin = newThickness;

        bool overlaps = CheckForOverlap();

        SetColor(overlaps ? Colors.Red : Colors.Green);
    }

    // Check the current position for overlaps with all other controls
    private bool CheckForOverlap()
    {
        if (_otherRects == null || _otherRects.Count == 0)
            return false;

        Rect thisRect = GetRect(_child);
        foreach(Rect otherRect in _otherRects)
            if (thisRect.IntersectsWith(otherRect))
                return true;

        return false;
    }

    private Rect GetRect(FrameworkElement element)
    {
        return new Rect(new Point(element.Margin.Left, element.Margin.Top), new Size(element.ActualWidth, element.ActualHeight));
    }

    private void RectOnMouseLeftButtonUp(object sender, MouseButtonEventArgs args)
    {
        if (!_down) return;

        Point pos = args.GetPosition(_parent);

        UpdateMargin(pos);

        if (CheckForOverlap())
            ResetMargin();

        _down = false;
        _rect.ReleaseMouseCapture();
        SetColor(Colors.LightGray);
    }

    private void ResetMargin()
    {
        _child.Margin = _downMargin;
    }

    private void RectOnMouseLeftButtonDown(object sender, MouseButtonEventArgs args)
    {
        _down = true;
        _rect.CaptureMouse();
        _downPos = args.GetPosition(_parent);
        _downMargin = _child.Margin;

        // The current position of all other elements doesn't have to be updated
        // while we move this one so we only determine it once
        _otherRects = new List<Rect>();
        foreach (FrameworkElement child in _parent.Children)
        {
            if (ReferenceEquals(child, _child))
                continue;
            _otherRects.Add(GetRect(child));
        }
    }

    // Whenever the adorned control is resized or moved
    // Update the size of the overlay rectangle
    // (Not 100% necessary as long as you only move it)
    protected override Size MeasureOverride(Size constraint)
    {
        _rect.Measure(constraint);
        return base.MeasureOverride(constraint);
    }

    protected override Size ArrangeOverride(Size finalSize)
    {
        _rect.Arrange(new Rect(new Point(0,0), finalSize));
        return base.ArrangeOverride(finalSize);
    }
}

演示XAML

private void DisableEditing(Grid theGrid)
{
    // Remove all Adorners of all Controls
    foreach (FrameworkElement child in theGrid.Children)
    {
        var layer = AdornerLayer.GetAdornerLayer(child);
        var adorners = layer.GetAdorners(child);
        if (adorners == null)
            continue;
        foreach(var adorner in adorners)
            layer.Remove(adorner);
    }
}

private void EnableEditing(Grid theGrid)
{
    foreach (FrameworkElement child in theGrid.Children)
    {
        // Add a MoveAdorner for every single child
        Adorner adorner = new MoveAdorner(child);

        // Add the Adorner to the closest (hierarchically speaking) AdornerLayer
        AdornerLayer.GetAdornerLayer(child).Add(adorner);
    }
}

预期结果

禁用编辑时无法移动控件，可以无阻碍地单击/交互交互式控件。启用编辑模式后，每个控件都会覆盖一个可以移动的装饰器。如果目标位置与另一个控件重叠，则如果用户放开鼠标按钮，则装饰器将变为红色并且边距将重置为初始位置。

Answer 2

没有其他方法可以检查您移动的地方是否存在控制权。

由于你要移动很多UI元素，最好使用canvas而不是grid，你可以使用Top和Left参数布局元素。

以下是修改后的代码

@Query("DELETE FROM User.TABLE_NAME")
public void nukeTable();

@Query("DELETE FROM " + User.TABLE_NAME + " WHERE " + User.COLUMN_ID + " = :id")
int deleteById(long id);

的Xaml

public partial class MainWindow : Window
{
    public bool _isInDrag = false;
    public Dictionary<object, TranslateTransform> PointDict = new Dictionary<object, TranslateTransform>();
    public Point _anchorPoint;
    public Point _currentPoint;

    public MainWindow()
    {
        InitializeComponent();
    }

    public void Control_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        if (_isInDrag)
        {
            var element = sender as FrameworkElement;
            element.ReleaseMouseCapture();
            Panel.SetZIndex(element, 0);
            _isInDrag = false;
            e.Handled = true;
        }
    }
    public void Control_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        var element = sender as FrameworkElement;
        _anchorPoint = e.GetPosition(null);
        element.CaptureMouse();
        Panel.SetZIndex(element, 10);
        _isInDrag = true;
        e.Handled = true;
    }
    public void Control_MouseMove(object sender, MouseEventArgs e)
    {
        if (_isInDrag)
        {
            _currentPoint = e.GetPosition(null);
            FrameworkElement fw = sender as FrameworkElement;
            if (fw != null)
            {
                FrameworkElement fwParent = fw.Parent as FrameworkElement;
                if (fwParent != null)
                {
                    Point p = new Point(_currentPoint.X - _anchorPoint.X + Canvas.GetLeft((sender as UIElement)), _currentPoint.Y - _anchorPoint.Y + Canvas.GetTop((sender as UIElement)));
                    List<HitTestResult> lst = new List<HitTestResult>()
                    {
                        VisualTreeHelper.HitTest(fwParent  , p),
                        VisualTreeHelper.HitTest(fwParent, new Point(p.X + fw.Width, p.Y)),
                        VisualTreeHelper.HitTest(fwParent, new Point(p.X, p.Y + fw.Height)),
                        VisualTreeHelper.HitTest(fwParent, new Point(p.X + fw.Width, p.Y +fw.Height)),
                    };
                    bool success = true;
                    foreach (var item in lst)
                    {
                        if (item != null)
                        {
                            if (item.VisualHit != sender && item.VisualHit != fwParent && fw.IsAncestorOf(item.VisualHit) == false)
                            {
                                success = false;
                                break;
                            }
                        }
                    }
                    if (success)
                    {
                        Canvas.SetTop((sender as UIElement), p.Y);
                        Canvas.SetLeft((sender as UIElement), p.X);
                        _anchorPoint = _currentPoint;
                    }
                }
            }
        }
    }
}

阻止WPF控件在MouseMove事件

2 个答案: