WinForm圆角按钮

WinForm自带的按钮是方形的，而且边框宽度、颜色等也无法指定，要想实现现在流行的圆角按钮，只能自己实现了，效果如下:

在窗体设计器中，右键单击按钮属性，可以设置背景色、圆角直径、按钮文本、文本颜色，其它需要的属性可以自行添加，下面有源代码

开发工具:VisualStudio 2019，其它版本也可以

1、在项目中添加用户控件，给用户控件命名

2、用户控件的后台代码:

public partial class JttCornerRadiusLabel : UserControl
    {
        GraphicsPath graphicsPath = new GraphicsPath();
        int cornerDiameter = 16;
        public JttCornerRadiusLabel()
        {
            InitializeComponent();
            this.BackColor = Color.Transparent;
            this.Paint += JttCornerRadiusLabel_Paint;
            stringFormat.Alignment = StringAlignment.Center;
            stringFormat.LineAlignment = StringAlignment.Center;
            penBrush = new SolidBrush(textColor);
        }


        public int CornerDiameter
        {
            get { return cornerDiameter; }
            set { cornerDiameter = value; Invalidate(); }
        }
        string labelText = "label1";
        public String LabelText
        {
            get
            {
                return labelText;
            }
            set
            {
                labelText = value;
                var size = GetSizeF(value);
                if(size.Width>this.Width)
                {
                    this.Width = size.Width;
                }
                if(size.Height>this.Height)
                {
                    this.Height = size.Height;
                }
                Invalidate();
            }
        }
        Color backFillColor = JttDTPColor.SelectedColor;
        public Color BackFillColor
        {
            get
            {
                return backFillColor;
            }
            set
            {
                backFillColor = value;
                Invalidate();
            }
        }
        private Size GetSizeF(string value)
        {
            if (string.IsNullOrEmpty(value))
            {
                return this.MinimumSize;
            }
            using (var g = this.CreateGraphics())
            {
                var sizeF = g.MeasureString(value, this.Font);
                return new Size((int)sizeF.Width + 10, (int)sizeF.Height + 10);
            }
        }
        /// <summary>
        /// 右上角弧线
        /// </summary>
        /// <returns></returns>
        private Rectangle GetCornerRect1()
        {
            return new Rectangle(Width - cornerDiameter - 1, 1, cornerDiameter, cornerDiameter);
        }
        /// <summary>
        /// 右边线段
        /// </summary>
        /// <returns></returns>
        private Tuple<Point, Point> GetLine1()
        {
            return new Tuple<Point, Point>(new Point(Width - 1, cornerDiameter / 2),
                new Point(Width - 1, Height - cornerDiameter / 2));
        }
        /// <summary>
        /// 右下角弧线
        /// </summary>
        /// <returns></returns>
        private Rectangle GetCornerRect2()
        {
            return new Rectangle(Width - cornerDiameter - 1, Height - cornerDiameter - 1, cornerDiameter, cornerDiameter);
        }
        /// <summary>
        /// 下边线段
        /// </summary>
        /// <returns></returns>
        private Tuple<Point, Point> GetLine2()
        {
            return new Tuple<Point, Point>(new Point(cornerDiameter / 2 + 1, Height - 1),
                new Point(Width - cornerDiameter / 2 - 1, Height - 1));
        }
        /// <summary>
        /// 左下角弧线
        /// </summary>
        /// <returns></returns>
        private Rectangle GetCornerRect3()
        {
            return new Rectangle(1, Height - cornerDiameter - 1, cornerDiameter, cornerDiameter);
        }
        /// <summary>
        /// 左边线段
        /// </summary>
        /// <returns></returns>
        private Tuple<Point, Point> GetLine3()
        {
            return new Tuple<Point, Point>(new Point(1, Height - cornerDiameter / 2 - 1),
                new Point(1, cornerDiameter / 2 + 1));
        }
        /// <summary>
        /// 左上角弧线
        /// </summary>
        /// <returns></returns>
        private Rectangle GetCornerRect4()
        {
            return new Rectangle(1, 1, cornerDiameter, cornerDiameter);
        }
        /// <summary>
        /// 上边线段
        /// </summary>
        /// <returns></returns>
        private Tuple<Point, Point> GetLine4()
        {
            return new Tuple<Point, Point>(
                new Point(cornerDiameter / 2 + 1, 1), new Point(Width - cornerDiameter / 2 - 1, 1));
        }

        StringFormat stringFormat = new StringFormat();
        Color textColor = Color.White;
        public Color TextColor
        {
            get
            {
                return textColor;
            }
            set
            {
                textColor = value;
                penBrush.Color = textColor;
                Invalidate();
            }
        }
        SolidBrush penBrush;
        private void JttCornerRadiusLabel_Paint(object sender, PaintEventArgs e)
        {
            using (var g = e.Graphics)
            {
                g.SmoothingMode = SmoothingMode.HighQuality;  //图片柔顺模式选择
                g.InterpolationMode = InterpolationMode.HighQualityBicubic;//高质量
                g.CompositingQuality = CompositingQuality.HighQuality;//再加一点

                graphicsPath.Reset();

                graphicsPath.AddArc(GetCornerRect1(), 270, 90);
                var points = GetLine1();
                graphicsPath.AddLine(points.Item1, points.Item2);

                graphicsPath.AddArc(GetCornerRect2(), 0, 90);
                points = GetLine2();
                graphicsPath.AddLine(points.Item1, points.Item2);

                graphicsPath.AddArc(GetCornerRect3(), 90, 90);
                points = GetLine3();
                graphicsPath.AddLine(points.Item1, points.Item2);

                graphicsPath.AddArc(GetCornerRect4(), 180, 90);
                points = GetLine4();
                graphicsPath.AddLine(points.Item1, points.Item2);
                g.FillPath(new SolidBrush(backFillColor), graphicsPath);
                g.DrawString(labelText, this.Font, penBrush, new RectangleF(0, 0, Width, Height),
                    stringFormat
                    );
            }
        }
    }

 

3、编译成功后，在工具栏中就可以拖拽创建圆角按钮了