blocks|key|1760885|text|我不确定这是否适用于所有情况，但多亏了这个线程，我们可以通过以下方式快速连接到Paint事件：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1760886|GroupBox+box+=+new+GroupBox();
[...]
box.Paint+%2B=+delegate(object+o,+PaintEventArgs+p)
{
++++p.Graphics.Clear(someColorHere);
};|code-block|syntax|javascript|1760887|干杯!|1760888|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I'm not sure this applies to every case, but thanks to this thread, we quickly hooked into the Paint event programmatically using:

<pre><code>GroupBox box = new GroupBox();
[...]
box.Paint += delegate(object o, PaintEventArgs p)
{
 p.Graphics.Clear(someColorHere);
};
</code></pre>

Cheers!

blocks|key|1546050|text|在前一个答案的基础上，提出了一个更好的解决方案，其中包括分组框的标签：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1546051|groupBox1.Paint+%2B=+PaintBorderlessGroupBox;

private+void+PaintBorderlessGroupBox(object+sender,+PaintEventArgs+p)
{
++GroupBox+box+=+(GroupBox)sender;
++p.Graphics.Clear(SystemColors.Control);
++p.Graphics.DrawString(box.Text,+box.Font,+Brushes.Black,+0,+0);
}|code-block|syntax|javascript|1546052|您可能想要调整文本的x/y，但对于我的使用来说，这恰到好处。|1546053|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Building on the previous answer, a better solution that includes the label for the group box:

<pre><code>groupBox1.Paint += PaintBorderlessGroupBox;

private void PaintBorderlessGroupBox(object sender, PaintEventArgs p)
{
 GroupBox box = (GroupBox)sender;
 p.Graphics.Clear(SystemColors.Control);
 p.Graphics.DrawString(box.Text, box.Font, Brushes.Black, 0, 0);
}
</code></pre>

You might want to adjust the x/y for the text, but for my use this is just right.

blocks|key|1546091|text|只需将任何对象(不仅仅是按钮)上的绘制操作设置为此方法即可绘制边框。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1546092|++++private+void+UserControl1_Paint(object+sender,+PaintEventArgs+e)
++++{
++++++++ControlPaint.DrawBorder(e.Graphics,+this.ClientRectangle,+Color.Red,+ButtonBorderStyle.Solid);

++++}|code-block|syntax|javascript|1546093|它仍然不会像原来的那样漂亮和圆润，但它要简单得多。|1546094|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Just set the paint action on any object (not just buttons) to this method to draw a border.

<pre><code> private void UserControl1_Paint(object sender, PaintEventArgs e)
 {
 ControlPaint.DrawBorder(e.Graphics, this.ClientRectangle, Color.Red, ButtonBorderStyle.Solid);

 }
</code></pre>

It still wont be pretty and rounded like the original, but it is much simpler.

blocks|key|1546111|text|只需添加paint事件。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1546112|++++private+void+groupBox1_Paint(object+sender,+PaintEventArgs+e)
++++{
++++++++GroupBox+box+=+sender+as+GroupBox;
++++++++DrawGroupBox(box,+e.Graphics,+Color.Red,+Color.Blue);
++++}


++++private+void+DrawGroupBox(GroupBox+box,+Graphics+g,+Color+textColor,+Color+borderColor)
++++{
++++++++if+(box+!=+null)
++++++++{
++++++++++++Brush+textBrush+=+new+SolidBrush(textColor);
++++++++++++Brush+borderBrush+=+new+SolidBrush(borderColor);
++++++++++++Pen+borderPen+=+new+Pen(borderBrush);
++++++++++++SizeF+strSize+=+g.MeasureString(box.Text,+box.Font);
++++++++++++Rectangle+rect+=+new+Rectangle(box.ClientRectangle.X,
+++++++++++++++++++++++++++++++++++++++++++box.ClientRectangle.Y+%2B+(int)(strSize.Height+/+2),
+++++++++++++++++++++++++++++++++++++++++++box.ClientRectangle.Width+-+1,
+++++++++++++++++++++++++++++++++++++++++++box.ClientRectangle.Height+-+(int)(strSize.Height+/+2)+-+1);

++++++++++++//+Clear+text+and+border
++++++++++++g.Clear(this.BackColor);

++++++++++++//+Draw+text
++++++++++++g.DrawString(box.Text,+box.Font,+textBrush,+box.Padding.Left,+0);

++++++++++++//+Drawing+Border
++++++++++++//Left
++++++++++++g.DrawLine(borderPen,+rect.Location,+new+Point(rect.X,+rect.Y+%2B+rect.Height));
++++++++++++//Right
++++++++++++g.DrawLine(borderPen,+new+Point(rect.X+%2B+rect.Width,+rect.Y),+new+Point(rect.X+%2B+rect.Width,+rect.Y+%2B+rect.Height));
++++++++++++//Bottom
++++++++++++g.DrawLine(borderPen,+new+Point(rect.X,+rect.Y+%2B+rect.Height),+new+Point(rect.X+%2B+rect.Width,+rect.Y+%2B+rect.Height));
++++++++++++//Top1
++++++++++++g.DrawLine(borderPen,+new+Point(rect.X,+rect.Y),+new+Point(rect.X+%2B+box.Padding.Left,+rect.Y));
++++++++++++//Top2
++++++++++++g.DrawLine(borderPen,+new+Point(rect.X+%2B+box.Padding.Left+%2B+(int)(strSize.Width),+rect.Y),+new+Point(rect.X+%2B+rect.Width,+rect.Y));
++++++++}
++++}|code-block|syntax|javascript|1546113|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Just add paint event.

<pre><code> private void groupBox1_Paint(object sender, PaintEventArgs e)
 {
 GroupBox box = sender as GroupBox;
 DrawGroupBox(box, e.Graphics, Color.Red, Color.Blue);
 }


 private void DrawGroupBox(GroupBox box, Graphics g, Color textColor, Color borderColor)
 {
 if (box != null)
 {
 Brush textBrush = new SolidBrush(textColor);
 Brush borderBrush = new SolidBrush(borderColor);
 Pen borderPen = new Pen(borderBrush);
 SizeF strSize = g.MeasureString(box.Text, box.Font);
 Rectangle rect = new Rectangle(box.ClientRectangle.X,
 box.ClientRectangle.Y + (int)(strSize.Height / 2),
 box.ClientRectangle.Width - 1,
 box.ClientRectangle.Height - (int)(strSize.Height / 2) - 1);

 // Clear text and border
 g.Clear(this.BackColor);

 // Draw text
 g.DrawString(box.Text, box.Font, textBrush, box.Padding.Left, 0);

 // Drawing Border
 //Left
 g.DrawLine(borderPen, rect.Location, new Point(rect.X, rect.Y + rect.Height));
 //Right
 g.DrawLine(borderPen, new Point(rect.X + rect.Width, rect.Y), new Point(rect.X + rect.Width, rect.Y + rect.Height));
 //Bottom
 g.DrawLine(borderPen, new Point(rect.X, rect.Y + rect.Height), new Point(rect.X + rect.Width, rect.Y + rect.Height));
 //Top1
 g.DrawLine(borderPen, new Point(rect.X, rect.Y), new Point(rect.X + box.Padding.Left, rect.Y));
 //Top2
 g.DrawLine(borderPen, new Point(rect.X + box.Padding.Left + (int)(strSize.Width), rect.Y), new Point(rect.X + rect.Width, rect.Y));
 }
 }
</code></pre>

blocks|key|1761070|text|FWIW，这是我使用的实现。它是GroupBox的子类，但它不仅允许设置BorderColor，还允许设置边框的厚度和圆角的半径。此外，您还可以设置GroupBox标签的缩进量，并从右侧使用负缩进量。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1761071|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+%2B=+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+%2B=+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+%2B+(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+%25+2)+?+rect.X+%2B+this._borderWidth+/+2+:+rect.X+%2B+1+%2B+this._borderWidth+/+2;
++++++++++++int+rectHeight+=+(0+==+this._borderWidth+%25+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+%2B+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
++++}
}|code-block|syntax|javascript|1761072|要让它起作用，你还必须扩展基本的Graphics类(注意:这是我在这里找到的一些代码的派生，当时我试图创建一个圆角面板控件，但我在这里找不到链接的原始帖子)：|1761073|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));
++++}
}|1761074|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

FWIW, this is the implementation I used. It's a child of GroupBox but allows setting not only the BorderColor, but also the thickness of the border and the radius of the rounded corners. Also, you can set the amount of indent you want for the GroupBox label, and using a negative indent indents from the right side.

<pre><code>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 =&gt; this._borderColor;
 set
 {
 this._borderColor = value;
 DrawGroupBox();
 }
 }

 public int BorderWidth
 {
 get =&gt; this._borderWidth;
 set
 {
 if (value &gt; 0)
 {
 this._borderWidth = Math.Min(value, 10);
 DrawGroupBox();
 }
 }
 }

 public int BorderRadius
 {
 get =&gt; this._borderRadius;
 set
 { // Setting a radius of 0 produces square corners...
 if (value &gt;= 0)
 {
 this._borderRadius = value;
 this.DrawGroupBox();
 }
 }
 }

 public int LabelIndent
 {
 get =&gt; this._textIndent;
 set
 {
 this._textIndent = value;
 this.DrawGroupBox();
 }
 }

 private void BorderedGroupBox_Paint(object sender, PaintEventArgs e) =&gt;
 DrawGroupBox(e.Graphics);

 private void DrawGroupBox() =&gt;
 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 &gt; 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 &lt; 0) ? Math.Max(0-width,this._textIndent) : Math.Min(width, this._textIndent);
 posX = (posX &lt; 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
 /// &lt;summary&gt;Required designer variable.&lt;/summary&gt;
 private System.ComponentModel.IContainer components = null;

 /// &lt;summary&gt;Clean up any resources being used.&lt;/summary&gt;
 /// &lt;param name="disposing"&gt;true if managed resources should be disposed; otherwise, false.&lt;/param&gt;
 protected override void Dispose(bool disposing)
 {
 if (disposing &amp;&amp; (components != null))
 components.Dispose();

 base.Dispose(disposing);
 }

 /// &lt;summary&gt;Required method for Designer support - Don't modify!&lt;/summary&gt;
 private void InitializeComponent() =&gt; components = new System.ComponentModel.Container();
 #endregion
 }
}
</code></pre>

To make it work, you also have to extend the base Graphics class (Note: this is derived from some code I found on here once when I was trying to create a rounded-corners Panel control, but I can't find the original post to link here):

<pre><code>static class GraphicsExtension
{
 private static GraphicsPath GenerateRoundedRectangle(
 this Graphics graphics,
 RectangleF rectangle,
 float radius)
 {
 float diameter;
 GraphicsPath path = new GraphicsPath();
 if (radius &lt;= 0.0F)
 {
 path.AddRectangle(rectangle);
 path.CloseFigure();
 return path;
 }
 else
 {
 if (radius &gt;= (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 &gt; 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 &lt; 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;
 }

 /// &lt;summary&gt;
 /// 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.
 /// &lt;/summary&gt;
 /// &lt;param name="brush"&gt;System.Drawing.Pen that determines the color, width and style of the rectangle.&lt;/param&gt;
 /// &lt;param name="x"&gt;The x-coordinate of the upper-left corner of the rectangle to draw.&lt;/param&gt;
 /// &lt;param name="y"&gt;The y-coordinate of the upper-left corner of the rectangle to draw.&lt;/param&gt;
 /// &lt;param name="width"&gt;Width of the rectangle to draw.&lt;/param&gt;
 /// &lt;param name="height"&gt;Height of the rectangle to draw.&lt;/param&gt;
 /// &lt;param name="radius"&gt;The radius of the arc used for the rounded edges.&lt;/param&gt;
 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;
 }

 /// &lt;summary&gt;
 /// 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.
 /// &lt;/summary&gt;
 /// &lt;param name="brush"&gt;System.Drawing.Pen that determines the color, width and style of the rectangle.&lt;/param&gt;
 /// &lt;param name="x"&gt;The x-coordinate of the upper-left corner of the rectangle to draw.&lt;/param&gt;
 /// &lt;param name="y"&gt;The y-coordinate of the upper-left corner of the rectangle to draw.&lt;/param&gt;
 /// &lt;param name="width"&gt;Width of the rectangle to draw.&lt;/param&gt;
 /// &lt;param name="height"&gt;Height of the rectangle to draw.&lt;/param&gt;
 /// &lt;param name="radius"&gt;The radius of the arc used for the rounded edges.&lt;/param&gt;

 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));
 }
}
</code></pre>

blocks|key|1546258|text|对Jim+Fell的代码的这个调整使边框对我来说更好一些，但是它太长了，不能作为注释添加|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1546259|..。|1546260|+++Rectangle+rect+=+new+Rectangle(this.ClientRectangle.X,
++++++++++++++++++++++++++++++++++++++++this.ClientRectangle.Y+%2B+(int)(strSize.Height+/+2),
++++++++++++++++++++++++++++++++++++++++this.ClientRectangle.Width,
++++++++++++++++++++++++++++++++++++++++this.ClientRectangle.Height+-+(int)(strSize.Height+/+2));

++++Brush+labelBrush+=+new+SolidBrush(this.BackColor);

++++//+Clear+text+and+border
++++g.Clear(this.BackColor);


++++int+drawX+=+rect.X;
++++int+drawY+=+rect.Y;
++++int+drawWidth+=+rect.Width;
++++int+drawHeight+=+rect.Height;

++++if+(this._borderWidth+>+0)
++++{
++++++++drawX+%2B=+this._borderWidth+/+2;
++++++++drawY+%2B=+this._borderWidth+/+2;

++++++++drawWidth+-=+this._borderWidth;
++++++++drawHeight+-=+this._borderWidth;
++++++++
++++++++if+(this._borderWidth+%25+2+==+0)
++++++++{
++++++++++++drawX+-=+1;
++++++++++++drawWidth+%2B=+1;

++++++++++++drawY+-=+1;
++++++++++++drawHeight+%2B=+1;
++++++++}
++++}

++++g.DrawRoundedRectangle(borderPen,+drawX,+drawY,+drawWidth,+drawHeight,+(float)this._borderRadius);|code-block|syntax|javascript|1546261|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

This tweak to Jim Fell's code placed the borders a little better for me, but it's too long to add as a comment
...
<pre><code> Rectangle rect = new Rectangle(this.ClientRectangle.X,
 this.ClientRectangle.Y + (int)(strSize.Height / 2),
 this.ClientRectangle.Width,
 this.ClientRectangle.Height - (int)(strSize.Height / 2));

 Brush labelBrush = new SolidBrush(this.BackColor);

 // Clear text and border
 g.Clear(this.BackColor);


 int drawX = rect.X;
 int drawY = rect.Y;
 int drawWidth = rect.Width;
 int drawHeight = rect.Height;

 if (this._borderWidth &gt; 0)
 {
 drawX += this._borderWidth / 2;
 drawY += this._borderWidth / 2;

 drawWidth -= this._borderWidth;
 drawHeight -= this._borderWidth;
 
 if (this._borderWidth % 2 == 0)
 {
 drawX -= 1;
 drawWidth += 1;

 drawY -= 1;
 drawHeight += 1;
 }
 }

 g.DrawRoundedRectangle(borderPen, drawX, drawY, drawWidth, drawHeight, (float)this._borderRadius);
</code></pre>

In C#.NET I am trying to programmatically change the color of the border in a group box.

Update: This question was asked when I was working on a winforms system before we switched to .NET.

How do you change the color of the border on a group box?

Windows

在C#.NET中，我尝试以编程方式更改分组框中边框的颜色。更新:在我们切换到.NET之前，我在winforms系统上工作时问过这个问题。

问如何更改分组框上边框的颜色？
EN

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问如何更改分组框上边框的颜色？
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