我在堆叠面板中有一个矩形形状，我想使用WPF用鼠标拖放到网格中！ 如果有人可以帮助我，我很感激吗？ 谢谢大家。
答案 0 :(得分：7)
接下来是一个非常简单的实现。它只需处理鼠标按钮向下/向上/移动Rectangle的事件，以便将其与鼠标移动一起定位。没有任何错误检查，也没有任何阻止用户将矩形拖离Canvas并将其留在那里。
XAML：
<Window x:Class="WpfApplication6.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Canvas Name="canvas">
<Rectangle
Name="rect"
Width="50"
Height="50"
Canvas.Left="0"
Canvas.Top="0"
Fill="Red"
MouseLeftButtonDown="rect_MouseLeftButtonDown"
MouseLeftButtonUp="rect_MouseLeftButtonUp"
MouseMove="rect_MouseMove"
/>
</Canvas>
</Grid>
</Window>
代码背后：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace WpfApplication6
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
private bool _isRectDragInProg;
public MainWindow()
{
InitializeComponent();
}
private void rect_MouseLeftButtonDown( object sender, MouseButtonEventArgs e )
{
_isRectDragInProg = true;
rect.CaptureMouse();
}
private void rect_MouseLeftButtonUp( object sender, MouseButtonEventArgs e )
{
_isRectDragInProg = false;
rect.ReleaseMouseCapture();
}
private void rect_MouseMove( object sender, MouseEventArgs e )
{
if( !_isRectDragInProg ) return;
// get the position of the mouse relative to the Canvas
var mousePos = e.GetPosition(canvas);
// center the rect on the mouse
double left = mousePos.X - (rect.ActualWidth / 2);
double top = mousePos.Y - (rect.ActualHeight / 2);
Canvas.SetLeft( rect, left );
Canvas.SetTop( rect, top );
}
}
}
答案 1 :(得分：0)
为了在项目控件中实现拖放，其中项目由画布以外的任何其他布局，我强烈建议您查看Bea Stollnitz solution。这是一个完全可重用的解决方案，可以使用附加属性在任何项目控件之间进行拖放。
更新：鉴于Bea的博客已经消失，还有其他基于她的解决方案的帖子仍然可用：
答案 2 :(得分：0)
扩展@Ed S的答案。使用Canvas的问题是，您基本上可以将控件拖到边界之外。如果要确保它不会越界，我创建了一个简单的应用程序，如果您有两个形状，则可以将它们一起移动或单独拖动。当然，我有一个名为ChkDual模式的复选框，用于确定形状是否必须一起移动。您可以根据需要编辑该功能。
<Grid>
<!--Set some height and width as you like-->
<Canvas x:Name="CnvBarCodeImage" AllowDrop="True">
</Canvas>
<Grid>
private void CreateUIShapes(int numberOfWindows)
{
//If you want multiple shapes put it inside a loop
Thumb th = null;
th = new Thumb();
th.Width = 200;
th.Height = 100;
th.Foreground = new SolidColorBrush(Windows.UI.Colors.Transparent);
th.BorderBrush = Colors.Green;
th.BorderThickness = new Thickness(3);
th.DragDelta += (sender, e) => Th_DragDelta(sender, e);
Canvas.SetLeft(th, 100);
Canvas.SetTop(th, 80);
CnvBarCodeImage.Children.Add(th);
}
private event Action<Thumb, double, double> ChangeDimensions;
private void Th_DragDelta(object sender, DragDeltaEventArgs e, List<Dimensions> limitedWindowMovements)
{
var selectedDraggableThumb = sender as Thumb;
double left = (Canvas.GetLeft(selectedDraggableThumb) >= 0) ? Canvas.GetLeft(selectedDraggableThumb) : 0;
double top = (Canvas.GetTop(selectedDraggableThumb) >= 0) ? Canvas.GetTop(selectedDraggableThumb) : 0;
if (ChkDualMode.IsChecked == true)
{
var otherDraggableThumbs = CnvBarCodeImage.Children.OfType<Thumb>().Where(x => x != selectedDraggableThumb).ToList();
var maxTopSelected = 0
var maxLeftSelected = 0;
//There may be n number of windows.
foreach (var item in otherDraggableThumbs)
{
//TOP
//Canvas.GetTop(SelectedDraggableThumb) <= 0 || Canvas.GetTop(item) <= 0 original.
if (Canvas.GetTop(selectedDraggableThumb) <= maxTopSelected || Canvas.GetTop(item) <= maxTopSelected)
{
if (e.VerticalChange <= 0)
{
ChangeDimensions -= BarCodeServiceView_ChangeDimensions;
return;
}
}
//LEFT
//Canvas.GetLeft(SelectedDraggableThumb) <= 0 || Canvas.GetLeft(item) <= 0 original.
else if (Canvas.GetLeft(selectedDraggableThumb) <= maxLeftSelected || Canvas.GetLeft(item) <= maxLeftSelected)
{
if (e.HorizontalChange <= 0)
{
ChangeDimensions -= BarCodeServiceView_ChangeDimensions;
return;
}
}
//RIGHT
else if (Canvas.GetLeft(selectedDraggableThumb) >=
CnvBarCodeImage.ActualWidth - selectedDraggableThumb.ActualWidth ||
Canvas.GetLeft(item) >= CnvBarCodeImage.ActualWidth - item.ActualWidth)
//|| Canvas.GetLeft(SelectedDraggableThumb) >= maxRightSelected
//|| Canvas.GetLeft(item) >= maxRightSelected)
{
if (e.HorizontalChange > 0)
{
ChangeDimensions -= BarCodeServiceView_ChangeDimensions;
return;
}
}
//BOTTOM
else if (Canvas.GetTop(selectedDraggableThumb) + selectedDraggableThumb.ActualHeight >= CnvBarCodeImage.ActualHeight ||
Canvas.GetTop(item) + item.ActualHeight >= CnvBarCodeImage.ActualHeight)
{
if (e.VerticalChange >= 0)
{
ChangeDimensions -= BarCodeServiceView_ChangeDimensions;
return;
}
}
if (ChangeDimensions == null)
{
ChangeDimensions += BarCodeServiceView_ChangeDimensions;
}
}
foreach (var item in otherDraggableThumbs)
{
ChangeDimensions?.Invoke(item, e.HorizontalChange, e.VerticalChange);
}
left = (Canvas.GetLeft(selectedDraggableThumb) >= CnvBarCodeImage.ActualWidth) ? CnvBarCodeImage.ActualWidth : left;
top = (Canvas.GetTop(selectedDraggableThumb) >= CnvBarCodeImage.ActualHeight) ? CnvBarCodeImage.ActualHeight : top;
Canvas.SetLeft(selectedDraggableThumb, left + e.HorizontalChange);
Canvas.SetTop(selectedDraggableThumb, top + e.VerticalChange);
}
else
{
//In single mode limit the movement as well.
int.TryParse(selectedDraggableThumb.Name, out var indexFromName);
var limitedDimensionForWindow = limitedWindowMovements[indexFromName];
var maxTop = limitedDimensionForWindow.MaxTopPossible == null ? 0 : limitedDimensionForWindow.MaxTopPossible;
var maxLeft = limitedDimensionForWindow.MaxLeftPossible == null ? 0 : limitedDimensionForWindow.MaxLeftPossible;
var maxRight = limitedDimensionForWindow.MaxRightPossible == null ? CnvBarCodeImage.ActualWidth - selectedDraggableThumb.ActualWidth : limitedDimensionForWindow.MaxRightPossible;
var maxBottom = limitedDimensionForWindow.MaxBottomPossible == null ? CnvBarCodeImage.ActualHeight - selectedDraggableThumb.ActualHeight : limitedDimensionForWindow.MaxBottomPossible;
if (Canvas.GetTop(selectedDraggableThumb) <= maxTop)
{
if (e.VerticalChange <= 0)
{
return;
}
}
else if (Canvas.GetLeft(selectedDraggableThumb) <= maxLeft)
{
if (e.HorizontalChange <= 0)
{
return;
}
}
else if (Canvas.GetLeft(selectedDraggableThumb) >= maxRight)
{
if (e.HorizontalChange >= 0)
{
return;
}
}
else if (Canvas.GetTop(selectedDraggableThumb) >= maxBottom)
{
if (e.VerticalChange >= 0)
{
return;
}
}
left = (Canvas.GetLeft(selectedDraggableThumb) >= CnvBarCodeImage.ActualWidth) ? CnvBarCodeImage.ActualWidth : left;
top = (Canvas.GetTop(selectedDraggableThumb) >= CnvBarCodeImage.ActualHeight) ? CnvBarCodeImage.ActualHeight : top;
Canvas.SetLeft(selectedDraggableThumb, left + e.HorizontalChange);
Canvas.SetTop(selectedDraggableThumb, top + e.VerticalChange);
}
}
private void BarCodeServiceView_ChangeDimensions(Thumb sender, double arg1, double arg2)
{
if (sender != null)
{
double left = (Canvas.GetLeft(sender) > 0) ? Canvas.GetLeft(sender) : 0;
double top = (Canvas.GetTop(sender) > 0) ? Canvas.GetTop(sender) : 0;
Canvas.SetLeft(sender, left + arg1);
Canvas.SetTop(sender, top + arg2);
}
}