用DrawingContext.DrawRectangle块鼠标绘制的矩形
用DrawingContext.DrawRectangle块鼠标绘制的矩形
提问于 2012-11-11 05:24:59
下面的WPF程序打开一个窗口，如下所示：
鼠标在黑色方块外移动会导致窗口标题根据鼠标的位置进行更新。当鼠标进入正方形时，更新停止。
我希望即使鼠标在方块上，MouseMove也能继续触发。有没有办法做到这一点？
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
namespace Wpf_Particle_Demo
{
class DrawingVisualElement : FrameworkElement
{
public DrawingVisual visual;
public DrawingVisualElement() { visual = new DrawingVisual(); }
protected override int VisualChildrenCount { get { return 1; } }
protected override Visual GetVisualChild(int index) { return visual; }
}
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
var canvas = new Canvas();
Content = canvas;
var element = new DrawingVisualElement();
canvas.Children.Add(element);
CompositionTarget.Rendering += (s, e) =>
{
using (var dc = element.visual.RenderOpen())
dc.DrawRectangle(Brushes.Black, null, new Rect(0, 0, 50, 50));
};
MouseMove += (s, e) => Title = e.GetPosition(canvas).ToString();
}
}
}回答 3
Stack Overflow用户
回答已采纳
发布于 2012-11-11 06:13:02
您将需要Capture鼠标这将允许您的Canvas继续响应MouseMove事件，尝试像这样它将更新您的坐标只要鼠标被按下
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
var canvas = new Canvas();
Content = canvas;
var element = new DrawingVisualElement();
canvas.Children.Add(element);
CompositionTarget.Rendering += (s, e) =>
{
using (var dc = element.visual.RenderOpen())
dc.DrawRectangle(Brushes.Black, null, new Rect(0, 0, 50, 50));
};
Mouse.Capture(canvas);
MouseDown += (s, e) => Mouse.Capture((UIElement)s);
MouseMove += (s, e) => Title = e.GetPosition(canvas).ToString();
MouseUp += (s, e) => Mouse.Capture(null);
}第二种方法
public MainWindow()
{
InitializeComponent();
var canvas = new Canvas();
Content = canvas;
DrawingVisualElement element = new DrawingVisualElement();
Grid myElement = new Grid();
canvas.Children.Add(myElement);
CompositionTarget.Rendering += (s, e) =>
{
using (var dc = element.visual.RenderOpen())
{
dc.DrawRectangle(Brushes.Black, null, new Rect(100, 0, 50, 50));
}
DrawingImage myImage = new DrawingImage(element.visual.Drawing);
myElement.Height = myImage.Height;
myElement.Width = myImage.Width;
myElement.Background = new ImageBrush(myImage);
};
MouseMove += (s, e) => Title = e.GetPosition(canvas).ToString();
}使用钩子的请确保将using System.Windows.Interop;
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
var canvas = new Canvas();
Content = canvas;
var element = new DrawingVisualElement();
canvas.Children.Add(element);
CompositionTarget.Rendering += (s, e) =>
{
using (var dc = element.visual.RenderOpen())
{
dc.DrawRectangle(Brushes.Black, null, new Rect(0, 0, 50, 50));
}
};
this.SourceInitialized += new EventHandler(OnSourceInitialized);
}
void OnSourceInitialized(object sender, EventArgs e)
{
HwndSource source = (HwndSource)PresentationSource.FromVisual(this);
source.AddHook(new HwndSourceHook(HandleMessages));
}
IntPtr HandleMessages(IntPtr hwnd, int msg,IntPtr wParam, IntPtr lParam, ref bool handled)
{
if (msg == 0x200)
Title = Mouse.GetPosition(this).ToString(); // because I did not want to split the lParam into High/Low values for Position information
return IntPtr.Zero;
}
}Stack Overflow用户
发布于 2012-11-11 06:55:33
到目前为止，最简单的方法是在窗口PreviewMouseDown上使用“隧道”事件。它首先被传递到窗口，然后在层次结构中向上移动。因此，窗口中有哪些其他元素根本无关紧要。在代码中：
public partial class Window1 : Window {
public Window1() {
InitializeComponent();
this.PreviewMouseMove += new MouseEventHandler(Window1_PreviewMouseMove);
}
void Window1_PreviewMouseMove(object sender, MouseEventArgs e) {
this.Title = e.GetPosition(this).ToString();
}
}Stack Overflow用户
发布于 2014-01-24 01:39:08
答案就简单多了。你需要做的就是设置element.IsHitTestVisible=false；
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/13326226
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