Steadily painted over (slow application)

Question

I am using the following code, but my application becomes quite slow. What I can do?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

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

namespace MyControl.Controls_1
{
    public class MyButton : Button
    { 
    //Fields
    private int borderSize = 0;
    private int borderRadius = 0;
    private Color borderColor = Color.PaleVioletRed;

    //Properties
    [Category("MyButton Code Advance")]
    public int BorderSize
    {
        get { return borderSize; }
        set
        {
            borderSize = value;
            this.Invalidate();
        }
    }

    [Category("MyButton Code Advance")]
    public int BorderRadius
    {
        get { return borderRadius; }
        set
        {
            borderRadius = value;
            this.Invalidate();
        }
    }

    [Category("MyButton Code Advance")]
    public Color BorderColor
    {
        get { return borderColor; }
        set
        {
            borderColor = value;
            this.Invalidate();
        }
    }

    [Category("MyButton Code Advance")]
    public Color BackgroundColor
    {
        get { return this.BackColor; }
        set { this.BackColor = value; }
    }

    [Category("MyButton Code Advance")]
    public Color TextColor
    {
        get { return this.ForeColor; }
        set { this.ForeColor = value; }
    }

    //Constructor
    public MyButtonButton()
    {
        this.FlatStyle = FlatStyle.Flat;
        this.FlatAppearance.BorderSize = 0;
        this.Size = new Size(150, 40);
        this.BackColor = Color.MediumSlateBlue;
        this.ForeColor = Color.White;
        this.Resize += new EventHandler(Button_Resize);
    }

    //Methods
    private GraphicsPath GetFigurePath(Rectangle rect, int radius)
    {
        GraphicsPath path = new GraphicsPath();
        float curveSize = radius * 2F;

        path.StartFigure();
        path.AddArc(rect.X, rect.Y, curveSize, curveSize, 180, 90);
        path.AddArc(rect.Right - curveSize, rect.Y, curveSize, curveSize, 270, 90);
        path.AddArc(rect.Right - curveSize, rect.Bottom - curveSize, curveSize, curveSize, 0, 90);
        path.AddArc(rect.X, rect.Bottom - curveSize, curveSize, curveSize, 90, 90);
        path.CloseFigure();
        return path;
    }

    protected override void OnPaint(PaintEventArgs pevent)
    {
        base.OnPaint(pevent);


        Rectangle rectSurface = this.ClientRectangle;
        Rectangle rectBorder = Rectangle.Inflate(rectSurface, -borderSize, -borderSize);
        int smoothSize = 2;
        if (borderSize > 0)
            smoothSize = borderSize;

        if (borderRadius > 2) //Rounded button
        {
            using (GraphicsPath pathSurface = GetFigurePath(rectSurface, borderRadius))
            using (GraphicsPath pathBorder = GetFigurePath(rectBorder, borderRadius - borderSize))
            using (Pen penSurface = new Pen(this.Parent.BackColor, smoothSize))
            using (Pen penBorder = new Pen(borderColor, borderSize))
            {
                pevent.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
                //Button surface
                this.Region = new Region(pathSurface);
                //Draw surface border for HD result
                pevent.Graphics.DrawPath(penSurface, pathSurface);

                //Button border                    
                if (borderSize >= 1)
                    //Draw control border
                    pevent.Graphics.DrawPath(penBorder, pathBorder);
            }
        }
        else //Normal button
        {
            pevent.Graphics.SmoothingMode = SmoothingMode.None;
            //Button surface
            this.Region = new Region(rectSurface);
            //Button border
            if (borderSize >= 1)
            {
                using (Pen penBorder = new Pen(borderColor, borderSize))
                {
                    penBorder.Alignment = PenAlignment.Inset;
                    pevent.Graphics.DrawRectangle(penBorder, 0, 0, this.Width - 1, this.Height - 1);
                }
            }
        }
    }
    protected override void OnHandleCreated(EventArgs e)
    {
        base.OnHandleCreated(e);
        this.Parent.BackColorChanged += new EventHandler(Container_BackColorChanged);
    }

    private void Container_BackColorChanged(object sender, EventArgs e)
    {
        this.Invalidate();
    }
    private void Button_Resize(object sender, EventArgs e)
    {
        if (borderRadius > this.Height)
            borderRadius = this.Height;
    }
}
}

Answer 1

Hi @FMMM , Welcome to Microsoft Q&A.

I tried to simplify your code to see if it works.

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

namespace WindowsFormsControlLibrary3
{
    public partial class MyButton : Button
    {
        private int borderSize = 0;
        private int borderRadius = 0;
        private Color borderColor = Color.PaleVioletRed;
        private Color backgroundColor = Color.MediumSlateBlue;
        private Color textColor = Color.White;

        public int BorderSize
        {
            get { return borderSize; }
            set
            {
                borderSize = value;
                Invalidate();
            }
        }

        public int BorderRadius
        {
            get { return borderRadius; }
            set
            {
                borderRadius = value;
                Invalidate();
            }
        }

        public Color BorderColor
        {
            get { return borderColor; }
            set
            {
                borderColor = value;
                Invalidate();
            }
        }

        public Color BackgroundColor
        {
            get { return backgroundColor; }
            set
            {
                backgroundColor = value;
                Invalidate();
            }
        }

        public Color TextColor
        {
            get { return textColor; }
            set
            {
                textColor = value;
                Invalidate();
            }
        }

        public MyButton()
        {
            FlatStyle = FlatStyle.Flat;
            FlatAppearance.BorderSize = 0;
            Size = new Size(150, 40);
            BackColor = backgroundColor;
            ForeColor = textColor;
            Resize += Button_Resize;
        }

        private GraphicsPath GetFigurePath(Rectangle rect, int radius)
        {
            GraphicsPath path = new GraphicsPath();

            if (radius == 0)
            {
                path.AddRectangle(rect);
            }
            else
            {
                int curveSize = radius * 2;

                path.AddArc(rect.X, rect.Y, curveSize, curveSize, 180, 90);
                path.AddArc(rect.Right - curveSize, rect.Y, curveSize, curveSize, 270, 90);
                path.AddArc(rect.Right - curveSize, rect.Bottom - curveSize, curveSize, curveSize, 0, 90);
                path.AddArc(rect.X, rect.Bottom - curveSize, curveSize, curveSize, 90, 90);
            }

            path.CloseFigure();
            return path;
        }

        protected override void OnPaint(PaintEventArgs pevent)
        {
            base.OnPaint(pevent);

            var rectSurface = ClientRectangle;
            var rectBorder = Rectangle.Inflate(rectSurface, -borderSize, -borderSize);
            int smoothSize = Math.Min(borderSize, 2);

            using (var pathSurface = GetFigurePath(rectSurface, borderRadius))
            using (var pathBorder = GetFigurePath(rectBorder, borderRadius - borderSize))
            using (var penSurface = new Pen(backgroundColor, smoothSize))
            using (var penBorder = new Pen(borderColor, borderSize))
            {
                pevent.Graphics.SmoothingMode = SmoothingMode.AntiAlias;

                Region = new Region(pathSurface);
                pevent.Graphics.DrawPath(penSurface, pathSurface);

                if (borderSize >= 1)
                    pevent.Graphics.DrawPath(penBorder, pathBorder);
            }
        }

        protected override void OnHandleCreated(EventArgs e)
        {
            base.OnHandleCreated(e);
            Parent.BackColorChanged += Container_BackColorChanged;
        }

        private void Container_BackColorChanged(object sender, EventArgs e)
        {
            Invalidate();
        }

        private void Button_Resize(object sender, EventArgs e)
        {
            if (borderRadius > Height)
                borderRadius = Height;
        }
    }
}

Best Regards,

Jiale

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