src/WpfEditor/ViewModel.cs

using CommunityToolkit.Mvvm.ComponentModel;
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Media.Imaging;

namespace WpfEditor
{
    // 矩形框数据模型
    public partial class RectangleItem : ObservableObject
    {
        [ObservableProperty]
        private int id;

        [ObservableProperty]
        private double left;

        [ObservableProperty]
        private double top;

        [ObservableProperty]
        private double width;

        [ObservableProperty]
        private double height;

        [ObservableProperty]
        private bool isVisible = true;

        [ObservableProperty]
        private bool isHovered = false;

        public RectangleItem(int id, double left, double top, double width, double height)
        {
            Id = id;
            Left = left;
            Top = top;
            Width = width;
            Height = height;
        }
    }

    public partial class ViewModel : ObservableObject
    {
        [ObservableProperty]
        private BitmapSource? image;

        [ObservableProperty]
        private bool isDrawingRectangle = false;

        // 保留原有的临时矩形属性，用于绘制过程中的预览
        [ObservableProperty]
        private double rectangleLeft = 0;

        [ObservableProperty]
        private double rectangleTop = 0;

        [ObservableProperty]
        private double rectangleWidth = 0;

        [ObservableProperty]
        private double rectangleHeight = 0;

        [ObservableProperty]
        private bool rectangleVisible = false;

        // 新增：矩形框集合
        [ObservableProperty]
        public ObservableCollection<RectangleItem> rectangles = new ObservableCollection<RectangleItem>();

        // 新增：矩形框计数器
        [ObservableProperty]
        public int rectangleCounter = 0;

        public ViewModel()
        {
            LoadSampleImage();
        }

        public void LoadImage(string filePath)
        {
            try
            {
                BitmapImage bitmap = new BitmapImage();
                bitmap.BeginInit();
                bitmap.UriSource = new Uri(filePath);
                bitmap.EndInit();
                
                Image = bitmap;
                // 清除所有矩形框
                ClearAllRectangles();
            }
            catch (Exception ex)
            {
                throw new Exception($"无法加载图片: {ex.Message}");
            }
        }

        // 添加新的矩形框
        public int AddRectangle(double left, double top, double width, double height)
        {
            RectangleCounter++;
            var newRectangle = new RectangleItem(RectangleCounter, left, top, width, height);
            Rectangles.Add(newRectangle);
            return RectangleCounter;
        }

        public int AddRectangle(int Id, double left, double top, double width, double height)
        {
            var newRectangle = new RectangleItem(Id, left, top, width, height);
            Rectangles.Add(newRectangle);
            RectangleCounter = Rectangles.Count;
            return RectangleCounter;
        }

        // 清除单个临时矩形（绘制过程中使用）
        public void ClearRectangle()
        {
            RectangleVisible = false;
            IsDrawingRectangle = false;
            RectangleLeft = 0;
            RectangleTop = 0;
            RectangleWidth = 0;
            RectangleHeight = 0;
        }

        // 清除所有矩形框
        public void ClearAllRectangles()
        {
            Rectangles.Clear();
            RectangleCounter = 0;
            ClearRectangle();
        }

        private void LoadSampleImage()
        {
            try
            {
                //Image = new BitmapImage(new Uri("pack://application:,,,/sample.jpg"));
            }
            catch
            {
                CreateTestImage();
            }
        }

        private void CreateTestImage()
        {
            var bitmap = new WriteableBitmap(800, 600, 96, 96, System.Windows.Media.PixelFormats.Bgr24, null);
            
            var stride = bitmap.PixelWidth * 3;
            var pixels = new byte[bitmap.PixelHeight * stride];
            
            for (int y = 0; y < bitmap.PixelHeight; y++)
            {
                for (int x = 0; x < bitmap.PixelWidth; x++)
                {
                    int index = y * stride + x * 3;
                    pixels[index] = (byte)(x % 256);
                    pixels[index + 1] = (byte)(y % 256);
                    pixels[index + 2] = (byte)((x + y) % 256);
                }
            }
            
            bitmap.WritePixels(new Int32Rect(0, 0, bitmap.PixelWidth, bitmap.PixelHeight), pixels, stride, 0);
            Image = bitmap;
        }

        // 在ViewModel类中添加
        public void ResetImageDimensions()
        {
            // 当加载新图片时调用，重置尺寸记录
            // 这个方法需要在MainWindow中调用
        }

        // 删除指定的矩形框
        public void RemoveRectangle(RectangleItem rectangle)
        {
            if (rectangle != null && Rectangles.Contains(rectangle))
            {
                Rectangles.Remove(rectangle);
            }
        }

        // 根据ID删除矩形框
        public void RemoveRectangleById(int id)
        {
            var rectangle = Rectangles.FirstOrDefault(r => r.Id == id);
            if (rectangle != null)
            {
                Rectangles.Remove(rectangle);
            }
        }
    }
}