using System;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace WinCustControls
{
    public partial class UCWaterTank : UserControl
    {
        public UCWaterTank()
        {
            InitializeComponent();
            SetStyle(ControlStyles.AllPaintingInWmPaint, true);//忽略窗口消息，减少闪烁
            SetStyle(ControlStyles.OptimizedDoubleBuffer, true);//绘制到缓冲区，减少闪烁
            SetStyle(ControlStyles.UserPaint, true);//控件由其自身而不是操作系统绘制
            SetStyle(ControlStyles.ResizeRedraw, true);//控件调整其大小时重绘
            SetStyle(ControlStyles.SupportsTransparentBackColor, true);//支持透明背景
            RectWidth = 2;
            this.Size = new Size(100, 200);
        }
        float fRatio = 0.0f;
        float fHeight = 0.0f;//实际水位高度
        private RectangleF valueRect;//水位深度矩形

        private int mValue;
        //中心放射颜色
        [DefaultValue(typeof(int), "0"), Description("当前水位值")]
        public int Value
        {
            get { return mValue; }
            set
            {
                if (value > maxValue)
                    mValue = maxValue;
                else if (value < 0)
                    mValue = 0;
                else
                    mValue = value;
                UpdateHeight();//更新比例数  实际矩形区域
                Invalidate();
            }
        }



        private int maxValue = 100;
        //中心放射颜色
        [DefaultValue(typeof(int), "100"), Description("最大水位值")]
        public int MaxValue
        {
            get { return maxValue; }
            set
            {
                if (value < mValue)
                    maxValue = mValue;
                else
                    maxValue = value;
                UpdateHeight();//更新比例数  实际矩形区域
                Invalidate();
            }
        }

        private Color valueColor = Color.Blue;
        [DefaultValue(typeof(Color), "Blue"), Description("水位深度颜色")]
        public Color ValueColor
        {
            get { return valueColor; }
            set
            {
                valueColor = value;
                Invalidate();
            }
        }

        private Color borderColor = Color.Gray;
        [DefaultValue(typeof(Color), "Gray"), Description("水池的边框颜色")]
        public Color BorderColor
        {
            get { return borderColor; }
            set
            {
                borderColor = value;
                Invalidate();
            }
        }

        private int rectWidth = 1;
        //中心放射颜色
        [DefaultValue(typeof(int), "1"), Description("水池的边框粗细")]
        public int RectWidth
        {
            get { return rectWidth; }
            set
            {
                rectWidth = value;
                UpdateHeight();//更新比例数  实际矩形区域
                Invalidate();
            }
        }
        /// <summary>
        /// 更新内部矩形的实际高度
        /// </summary>
        private void UpdateHeight()
        {
            UpdateRatio();
            //水位高度
            fHeight = (float)Value * fRatio;
            //水位的矩形结构
            valueRect = new RectangleF(rectWidth, Height - fHeight - rectWidth, Width - 2 * rectWidth - 1, fHeight);
        }

        /// <summary>
        /// 计算水池高度与最大水位值之间比例值
        /// </summary>
        private void UpdateRatio()
        {
            fRatio = (float)(Height - 2 * RectWidth) / (float)MaxValue;
        }

        protected override void OnSizeChanged(EventArgs e)
        {
            base.OnSizeChanged(e);
            UpdateHeight();
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            Graphics g = e.Graphics;
            g.SmoothingMode = SmoothingMode.AntiAlias;
            //画边框线的pen对象
            Pen pen = new Pen(new SolidBrush(borderColor), RectWidth);
            Rectangle rect = new Rectangle(0, 0, this.Width - 1, Height - 1);
            //外边框圆角矩形 
            GraphicsPath rectPath = PaintClass.GetRoundRectangle(rect, 5);
            //填充水位
            g.FillRectangle(new SolidBrush(ValueColor), valueRect);
            //画边框
            g.DrawPath(pen, rectPath);
        }
    }
}