C# 图片按钮特效：鼠标移入变浅，移出恢复原样 (ImageButtonHover类)

using System;
using System.Drawing.Imaging;

namespace CSFrameworkV6.Library.CommonClass
{
    /// <summary>
    /// 图片按钮特效：鼠标移入变浅，移出恢复原样
    /// </summary>
    public class ImageButtonHover
    {
        // 保存原始图片（用于恢复）
        private Image _originalImage;
        private PictureBox _pictureBox;
        private float _opacity = 0.8f;// 80% 透明度效果最佳

        public ImageButtonHover(PictureBox imageButton)
        {
            _pictureBox = imageButton;

            // 先把原始图片存起来
            _originalImage = imageButton.Image;

            imageButton.MouseEnter += PictureBox_MouseEnter;
            imageButton.MouseLeave += PictureBox_MouseLeave;
        }

        /// <summary>
        /// 设置透明度
        /// </summary>
        /// <param name="opacity"></param>
        public void Handing(float opacity = 0.8f)
        {
            _opacity = opacity;
        }

        /// <summary>
        ///  鼠标离开 → 恢复原图
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void PictureBox_MouseLeave(object? sender, EventArgs e)
        {
            _pictureBox.Image = _originalImage;
        }

        /// <summary>
        /// 鼠标进入 → 图片变浅
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        /// <exception cref="NotImplementedException"></exception>
        private void PictureBox_MouseEnter(object? sender, EventArgs e)
        {
            if (_originalImage == null) return;
            _pictureBox.Image = ChangeOpacity(_originalImage, _opacity);
        }

        /// <summary>
        /// 修改图片透明度（变浅效果）
        /// </summary>
        /// <param name="img">原始图片</param>
        /// <param name="opacity">透明度 0~1，越小越浅, 0.8效果最佳</param>
        /// <returns>变浅后的图片</returns>
        private Image ChangeOpacity(Image img, float opacity)
        {
            Bitmap bmp = new Bitmap(img.Width, img.Height);

            using (Graphics g = Graphics.FromImage(bmp))
            {
                ColorMatrix colorMatrix = new ColorMatrix();
                colorMatrix.Matrix33 = opacity; // 透明度

                ImageAttributes attributes = new ImageAttributes();
                attributes.SetColorMatrix(colorMatrix);

                g.DrawImage(
                    img,
                    new Rectangle(0, 0, img.Width, img.Height),
                    0, 0, img.Width, img.Height,
                    GraphicsUnit.Pixel,
                    attributes
                );
            }
            return bmp;
        }

    }
}

new ImageButtonHover(btnLogin).Handing();
new ImageButtonHover(btnCancel).Handing();