FWIW, это реализация, которую я использовал. Он является дочерним по отношению к GroupBox, но позволяет устанавливать не только BorderColor, но также толщину границы и радиус закругленных углов. Кроме того, вы можете установить желаемый отступ для метки GroupBox и использовать отрицательный отступ с правой стороны.
using System;
using System.Drawing;
using System.Windows.Forms;
namespace BorderedGroupBox
{
public class BorderedGroupBox : GroupBox
{
private Color _borderColor = Color.Black;
private int _borderWidth = 2;
private int _borderRadius = 5;
private int _textIndent = 10;
public BorderedGroupBox() : base()
{
InitializeComponent();
this.Paint += this.BorderedGroupBox_Paint;
}
public BorderedGroupBox(int width, float radius, Color color) : base()
{
this._borderWidth = Math.Max(1,width);
this._borderColor = color;
this._borderRadius = Math.Max(0,radius);
InitializeComponent();
this.Paint += this.BorderedGroupBox_Paint;
}
public Color BorderColor
{
get => this._borderColor;
set
{
this._borderColor = value;
DrawGroupBox();
}
}
public int BorderWidth
{
get => this._borderWidth;
set
{
if (value > 0)
{
this._borderWidth = Math.Min(value, 10);
DrawGroupBox();
}
}
}
public int BorderRadius
{
get => this._borderRadius;
set
{ // Setting a radius of 0 produces square corners...
if (value >= 0)
{
this._borderRadius = value;
this.DrawGroupBox();
}
}
}
public int LabelIndent
{
get => this._textIndent;
set
{
this._textIndent = value;
this.DrawGroupBox();
}
}
private void BorderedGroupBox_Paint(object sender, PaintEventArgs e) =>
DrawGroupBox(e.Graphics);
private void DrawGroupBox() =>
this.DrawGroupBox(this.CreateGraphics());
private void DrawGroupBox(Graphics g)
{
Brush textBrush = new SolidBrush(this.ForeColor);
SizeF strSize = g.MeasureString(this.Text, this.Font);
Brush borderBrush = new SolidBrush(this.BorderColor);
Pen borderPen = new Pen(borderBrush,(float)this._borderWidth);
Rectangle rect = new Rectangle(this.ClientRectangle.X,
this.ClientRectangle.Y + (int)(strSize.Height / 2),
this.ClientRectangle.Width - 1,
this.ClientRectangle.Height - (int)(strSize.Height / 2) - 1);
Brush labelBrush = new SolidBrush(this.BackColor);
// Clear text and border
g.Clear(this.BackColor);
// Drawing Border (added "Fix" from Jim Fell, Oct 6, '18)
int rectX = (0 == this._borderWidth % 2) ? rect.X + this._borderWidth / 2 : rect.X + 1 + this._borderWidth / 2;
int rectHeight = (0 == this._borderWidth % 2) ? rect.Height - this._borderWidth / 2 : rect.Height - 1 - this._borderWidth / 2;
// NOTE DIFFERENCE: rectX vs rect.X and rectHeight vs rect.Height
g.DrawRoundedRectangle(borderPen, rectX, rect.Y, rect.Width, rectHeight, (float)this._borderRadius);
// Draw text
if (this.Text.Length > 0)
{
// Do some work to ensure we don't put the label outside
// of the box, regardless of what value is assigned to the Indent:
int width = (int)rect.Width, posX;
posX = (this._textIndent < 0) ? Math.Max(0-width,this._textIndent) : Math.Min(width, this._textIndent);
posX = (posX < 0) ? rect.Width + posX - (int)strSize.Width : posX;
g.FillRectangle(labelBrush, posX, 0, strSize.Width, strSize.Height);
g.DrawString(this.Text, this.Font, textBrush, posX, 0);
}
}
#region Component Designer generated code
/// <summary>Required designer variable.</summary>
private System.ComponentModel.IContainer components = null;
/// <summary>Clean up any resources being used.</summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
components.Dispose();
base.Dispose(disposing);
}
/// <summary>Required method for Designer support - Don't modify!</summary>
private void InitializeComponent() => components = new System.ComponentModel.Container();
#endregion
}
}
Чтобы это работало, вы также должны расширить базовый класс Graphics (Примечание: это происходит от некоторого кода, который я нашел здесь однажды, когда пытался создать элемент управления Panel с закругленными углами, но я не могу найти Оригинальный пост по ссылке здесь):
static class GraphicsExtension
{
private static GraphicsPath GenerateRoundedRectangle(
this Graphics graphics,
RectangleF rectangle,
float radius)
{
float diameter;
GraphicsPath path = new GraphicsPath();
if (radius <= 0.0F)
{
path.AddRectangle(rectangle);
path.CloseFigure();
return path;
}
else
{
if (radius >= (Math.Min(rectangle.Width, rectangle.Height)) / 2.0)
return graphics.GenerateCapsule(rectangle);
diameter = radius * 2.0F;
SizeF sizeF = new SizeF(diameter, diameter);
RectangleF arc = new RectangleF(rectangle.Location, sizeF);
path.AddArc(arc, 180, 90);
arc.X = rectangle.Right - diameter;
path.AddArc(arc, 270, 90);
arc.Y = rectangle.Bottom - diameter;
path.AddArc(arc, 0, 90);
arc.X = rectangle.Left;
path.AddArc(arc, 90, 90);
path.CloseFigure();
}
return path;
}
private static GraphicsPath GenerateCapsule(
this Graphics graphics,
RectangleF baseRect)
{
float diameter;
RectangleF arc;
GraphicsPath path = new GraphicsPath();
try
{
if (baseRect.Width > baseRect.Height)
{
diameter = baseRect.Height;
SizeF sizeF = new SizeF(diameter, diameter);
arc = new RectangleF(baseRect.Location, sizeF);
path.AddArc(arc, 90, 180);
arc.X = baseRect.Right - diameter;
path.AddArc(arc, 270, 180);
}
else if (baseRect.Width < baseRect.Height)
{
diameter = baseRect.Width;
SizeF sizeF = new SizeF(diameter, diameter);
arc = new RectangleF(baseRect.Location, sizeF);
path.AddArc(arc, 180, 180);
arc.Y = baseRect.Bottom - diameter;
path.AddArc(arc, 0, 180);
}
else path.AddEllipse(baseRect);
}
catch { path.AddEllipse(baseRect); }
finally { path.CloseFigure(); }
return path;
}
/// <summary>
/// Draws a rounded rectangle specified by a pair of coordinates, a width, a height and the radius
/// for the arcs that make the rounded edges.
/// </summary>
/// <param name="brush">System.Drawing.Pen that determines the color, width and style of the rectangle.</param>
/// <param name="x">The x-coordinate of the upper-left corner of the rectangle to draw.</param>
/// <param name="y">The y-coordinate of the upper-left corner of the rectangle to draw.</param>
/// <param name="width">Width of the rectangle to draw.</param>
/// <param name="height">Height of the rectangle to draw.</param>
/// <param name="radius">The radius of the arc used for the rounded edges.</param>
public static void DrawRoundedRectangle(
this Graphics graphics,
Pen pen,
float x,
float y,
float width,
float height,
float radius)
{
RectangleF rectangle = new RectangleF(x, y, width, height);
GraphicsPath path = graphics.GenerateRoundedRectangle(rectangle, radius);
SmoothingMode old = graphics.SmoothingMode;
graphics.SmoothingMode = SmoothingMode.AntiAlias;
graphics.DrawPath(pen, path);
graphics.SmoothingMode = old;
}
/// <summary>
/// Draws a rounded rectangle specified by a pair of coordinates, a width, a height and the radius
/// for the arcs that make the rounded edges.
/// </summary>
/// <param name="brush">System.Drawing.Pen that determines the color, width and style of the rectangle.</param>
/// <param name="x">The x-coordinate of the upper-left corner of the rectangle to draw.</param>
/// <param name="y">The y-coordinate of the upper-left corner of the rectangle to draw.</param>
/// <param name="width">Width of the rectangle to draw.</param>
/// <param name="height">Height of the rectangle to draw.</param>
/// <param name="radius">The radius of the arc used for the rounded edges.</param>
public static void DrawRoundedRectangle(
this Graphics graphics,
Pen pen,
int x,
int y,
int width,
int height,
int radius)
{
graphics.DrawRoundedRectangle(
pen,
Convert.ToSingle(x),
Convert.ToSingle(y),
Convert.ToSingle(width),
Convert.ToSingle(height),
Convert.ToSingle(radius));
}
}