using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Lskj.Main.Control
{
    public partial class BackgroundPanel :Panel
    {
        private Image _originalBackgroundImage;

        // 公开属性：设置/获取背景图片
        public Image BackgroundImageCustom
        {
            get => _originalBackgroundImage;
            set
            {
                _originalBackgroundImage = value;
                Invalidate(); // 设置图片后立即重绘
            }
        }

        public BackgroundPanel()
        {
            // 关键设置：关闭Panel默认背景，启用双缓冲减少闪烁
            this.BackgroundImage = null;
            this.DoubleBuffered = true;
            this.SetStyle(ControlStyles.UserPaint |
                           ControlStyles.AllPaintingInWmPaint |
                           ControlStyles.OptimizedDoubleBuffer, true);
        }

        // 重写OnPaint方法，手动绘制背景图
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);

            // 图片为空时直接返回
            if (_originalBackgroundImage == null) return;

            // 1. 计算等比缩放比例（以Panel的ClientSize为基准）
            float scaleX = (float)this.ClientSize.Width / _originalBackgroundImage.Width;
            float scaleY = (float)this.ClientSize.Height / _originalBackgroundImage.Height;
            float scale = Math.Min(scaleX, sc