使用wpf和MVVM制作一个可以旋转的机械手臂

好的，下面是一个简单的示例，可以通过鼠标拖拽旋转机械臂的关节。

首先，在XAML中创建一个包含机械臂的控件。这个控件由多个部分组成，每个部分都是一个矩形，代表机械臂的一个关节。这些矩形通过旋转变换连接在一起，形成一个完整的机械臂。

<UserControl x:Class="MechanicalArm.Views.MechanicalArmControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:MechanicalArm.Views"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800"
             Cursor="Hand">
    <Canvas Background="White">
        <!-- 机械臂关节1 -->
        <Rectangle x:Name="Joint1" Width="30" Height="80" Fill="Gray" Canvas.Left="100" Canvas.Top="100">
            <Rectangle.RenderTransform>
                <TransformGroup>
                    <TranslateTransform X="-15" Y="0"/>
                    <RotateTransform x:Name="Joint1Rotation" Angle="0" />
                    <TranslateTransform X="15" Y="0"/>
                </TransformGroup>
            </Rectangle.RenderTransform>
            <Rectangle.RenderTransformOrigin>
                <Point X="0.5" Y="0.5"/>
            </Rectangle.RenderTransformOrigin>
        </Rectangle>
        <!-- 机械臂关节2 -->
        <Rectangle x:Name="Joint2" Width="30" Height="80" Fill="Gray" Canvas.Left="130" Canvas.Top="100">
            <Rectangle.RenderTransform>
                <TransformGroup>
                    <TranslateTransform X="-15" Y="0"/>
                    <RotateTransform x:Name="Joint2Rotation" Angle="0"/>
                    <TranslateTransform X="15" Y="0"/>
                </TransformGroup>
            </Rectangle.RenderTransform>
            <Rectangle.RenderTransformOrigin>
                <Point X="0.5" Y="0.5"/>
            </Rectangle.RenderTransformOrigin>
        </Rectangle>
        <!-- 机械臂关节3 -->
        <Rectangle x:Name="Joint3" Width="30" Height="80" Fill="Gray" Canvas.Left="160" Canvas.Top="100">
            <Rectangle.RenderTransform>
                <TransformGroup>
                    <TranslateTransform X="-15" Y="0"/>
                    <RotateTransform x:Name="Joint3Rotation" Angle="0"/>
                    <TranslateTransform X="15" Y="0"/>
                </TransformGroup>
            </Rectangle.RenderTransform>
            <Rectangle.RenderTransformOrigin>
                <Point X="0.5" Y="0.5"/>
            </Rectangle.RenderTransformOrigin>
        </Rectangle>
        <!-- 机械臂关节4 -->
        <Rectangle x:Name="Joint4" Width="30" Height="80" Fill="Gray" Canvas.Left="190" Canvas.Top="100">
            <Rectangle.RenderTransform>
                <TransformGroup>
                    <TranslateTransform X="-15" Y="0"/>
                    <RotateTransform x:Name="Joint4Rotation" Angle="0"/>
                    <TranslateTransform X="15" Y="0"/>
                </TransformGroup>
            </Rectangle.RenderTransform>
            <Rectangle.RenderTransformOrigin>
                <Point X="0.5" Y="0.5"/>
            </Rectangle.RenderTransformOrigin>
        </Rectangle>
        <!-- 机械臂末端 -->
        <Rectangle x:Name="EndEffector" Width="30" Height="40" Fill="Red" Canvas.Left="220" Canvas.Top="100"/>
    </Canvas>
</UserControl>

在ViewModel中，我们需要处理鼠标拖拽事件，以实现机械臂关节的旋转。为了方便起见，我们将所有的旋转角度都保存在一个数组中，然后根据数组中的值更新每个关节的旋转角度。

using System.Windows;
using System.Windows.Input;
using System.Windows.Media;

namespace MechanicalArm.ViewModels
{
    public class MechanicalArmViewModel : ViewModelBase
    {
        private Point _previousMousePosition;

        private double[] _jointAngles = new double[4];

        public MechanicalArmViewModel()
        {
            // 初始化关节角度
            for (int i = 0; i < _jointAngles.Length; i++)
            {
                _jointAngles[i] = 0;
            }
        }

        public double Joint1Angle
        {
            get => _jointAngles[0];
            set
            {
                _jointAngles[0] = value;
                OnPropertyChanged(nameof(Joint1Angle));
            }
        }

        public double Joint2Angle
        {
            get => _jointAngles[1];
            set
            {
                _jointAngles[1] = value;
                OnPropertyChanged(nameof(Joint2Angle));
            }
        }

        public double Joint3Angle
        {
            get => _jointAngles[2];
            set
            {
                _jointAngles[2] = value;
                OnPropertyChanged(nameof(Joint3Angle));
            }
        }

        public double Joint4Angle
        {
            get => _jointAngles[3];
            set
            {
                _jointAngles[3] = value;
                OnPropertyChanged(nameof(Joint4Angle));
            }
        }

        public void OnMouseDown(object sender, MouseButtonEventArgs e)
        {
            _previousMousePosition = e.GetPosition((IInputElement)sender);
            Mouse.OverrideCursor = Cursors.Hand;
            Mouse.Capture((IInputElement)sender);
        }

        public void OnMouseMove(object sender, MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                var currentMousePosition = e.GetPosition((IInputElement)sender);
                var delta = currentMousePosition - _previousMousePosition;
                _previousMousePosition = currentMousePosition;

                // 计算旋转角度
                var angle = delta.Y / 5;
                
                // 更新关节角度
                Joint1Angle += angle;
                Joint2Angle += angle;
                Joint3Angle += angle;
                Joint4Angle += angle;
            }
        }

        public void OnMouseUp(object sender, MouseButtonEventArgs e)
        {
            Mouse.OverrideCursor = null;
            Mouse.Capture(null);
        }
    }
}

最后，在MainWindow中将机械臂控件添加到界面上，并将ViewModel与控件绑定。

<Window x:Class="MechanicalArm.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:MechanicalArm"
        xmlns:viewmodels="clr-namespace:MechanicalArm.ViewModels"
        xmlns:views="clr-namespace:MechanicalArm.Views"
        mc:Ignorable="d"
        Title="Mechanical Arm" Height="450" Width="800">
    <Window.DataContext>
        <viewmodels:MechanicalArmViewModel />
    </Window.DataContext>
    <Grid>
        <views:MechanicalArmControl MouseDown="OnMouseDown" MouseMove="OnMouseMove" MouseUp="OnMouseUp"/>
    </Grid>
</Window>

现在，我们就可以通过鼠标拖拽旋转机械臂的关节了！