我在自定义组合框中找到了一些代码，用圆角绘制，渐变背景和投影。我认为它看起来很不错，所以我调整它以使用标签控件做同样的事情。
奇怪的是，当我将其中一个控件放到表单设计器上时，默认属性被设置并且它绘制得很好 - 我在表单上放了多个副本，它们都很好。
但是，当我尝试在运行时添加几个控件时，实际上只绘制了第一个版本。其他人最终只是空白的白盒子。
我真的不知道该怎么做。
标签代码如下（抱歉 - 很长！）
public class LabelEx : Label
{
private System.Drawing.Color _BorderColor = Color.FromArgb(141, 178, 227);
private float _BorderWidth = 1;
private System.Drawing.Color _BackgroundColor = Color.White;
private System.Drawing.Color _BackgroundColorGradient = Color.FromArgb(227, 235, 246);
private ControlGradientMode _BackgroundGradientMode = ControlGradientMode.Vertical;
private int _CornerRadius = 5;
private RoundedControlCorners _Corners = RoundedControlCorners.All;
private int _DropShadowThickness = 3;
private bool _DropShadowVisible = true;
private System.Drawing.Color _ShadowColor = Color.FromArgb(50, Color.Black);
private ControlStyles _LabelStyle = ControlStyles.Extended;
public enum ControlStyles
{
Standard,
Extended
}
public LabelEx()
{
//InitializeComponent();
}
/// <summary>Gets or sets the radius of the corners of the control.</summary>
//[Category("Appearance"), Description("This feature will round the corners of the control.")]
public int CornerRadius
{
get { return _CornerRadius; }
set
{
if (value > 35)
{
_CornerRadius = 35;
}
else
{
if (value < 1)
{
_CornerRadius = 1;
}
else
{
_CornerRadius = value;
}
}
Invalidate();
}
}
/// <summary>Turns on or off the control shadowing.</summary>
//[Category("Appearance"), Description("This feature will turn on control shadowing.")]
public bool DropShadowVisible
{
get { return _DropShadowVisible; }
set
{
_DropShadowVisible = value;
Invalidate();
}
}
/// <summary>Gets or sets the color of the control's border.</summary>
//[Category("Appearance"), Description("This feature will allow you to change the color of the control's border.")]
public System.Drawing.Color BorderColor
{
get { return _BorderColor; }
set
{
_BorderColor = value;
Invalidate();
}
}
/// <summary>Gets or Sets the control's border size.</summary>
//[Category("Appearance"), Description("This feature will allow you to set the control's border size.")]
public float BorderWidth
{
get { return _BorderWidth; }
set
{
if (value > 10)
{
_BorderWidth = 10;
}
else
{
if (value < 1)
{
_BorderWidth = 1;
}
else
{
_BorderWidth = value;
}
}
Invalidate();
}
}
/// <summary>Gets or sets the size of the shadow border thickness.</summary>
// [Category("Appearance"), Description("This feature will change the size of the shadow border.")]
public int DropShadowThickness
{
get { return _DropShadowThickness; }
set
{
if (value > 10)
{
_DropShadowThickness = 10;
}
else
{
if (value < 1)
{
_DropShadowThickness = 1;
}
else
{
_DropShadowThickness = value;
}
}
Invalidate();
}
}
/// <summary>Gets or sets the background color to use. This color can also be used in combination with BackgroundColorGradient for a gradient paint.</summary>
// [Category("Appearance"), Description("This feature will change the group control color. This color can also be used in combination with BackgroundColorGradient for a gradient paint.")]
public System.Drawing.Color BackgroundColor
{
get { return _BackgroundColor; }
set
{
_BackgroundColor = value;
Invalidate();
}
}
/// <summary>Specifies the second color when using the gradient mode.</summary>
// [Category("Appearance"), Description("This feature can be used in combination with BackgroundColor to create a gradient background.")]
public System.Drawing.Color BackgroundColorGradient
{
get { return _BackgroundColorGradient; }
set
{
_BackgroundColorGradient = value;
Invalidate();
}
}
/// <summary>This property secifies the type of gradient to use when painting the background.</summary>
// [Category("Appearance"), Description("This feature turns on background gradient painting.")]
public ControlGradientMode BackgroundGradientMode
{
get { return _BackgroundGradientMode; }
set
{
_BackgroundGradientMode = value;
Invalidate();
}
}
/// <summary>Specifies which corners to apply rounding for</summary>
public RoundedControlCorners Corners
{
get { return _Corners; }
set
{
_Corners = value;
Invalidate();
}
}
/// <summary>Gets or sets the Style for the GroupBox. Standard duplicates the stock groupbox. Extended allows the customization ability</summary>
// [Category("Appearance"), Description("Gets or sets the Style for the GroupBox. Standard duplicates the stock groupbox. Extended allows the customization ability")]
// [DefaultValue(ControlStyles.Extended)]
public ControlStyles LabelStyle
{
get { return _LabelStyle; }
set
{
_LabelStyle = value;
Invalidate();
}
}
/// <summary>
/// Function to paint the label as per what we want.
/// </summary>
/// <param name="e"></param>
protected override void OnPaint(PaintEventArgs e)
{
//Just use a normal label if the "standard" is set.
if (_LabelStyle == ControlStyles.Standard)
{
base.OnPaint(e);
return;
}
//we must set the smoothing mode to anti alias or high quality(They are the same) in order to get the
//nice rounded corders on our control
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
//first lets set the rectangles we will be drawing in. If the drop shadow is visible then we need to
//reduce the size of the main rectangle and create a second one that is offset by the shadow thickness.
Rectangle shadowRec = default(Rectangle);
Rectangle frameRec = default(Rectangle);
if (DropShadowVisible)
{
shadowRec = Rectangle.FromLTRB(DropShadowThickness, DropShadowThickness, this.ClientRectangle.Right - 1, this.ClientRectangle.Bottom - 1);
frameRec = Rectangle.FromLTRB(0, 0, this.ClientRectangle.Right - DropShadowThickness - 2, this.ClientRectangle.Bottom - DropShadowThickness - 2);
}
else
{
frameRec = Rectangle.FromLTRB(this.ClientRectangle.Left, this.ClientRectangle.Top, this.ClientRectangle.Right - 1, this.ClientRectangle.Bottom - 1);
}
if (frameRec.Height <= 0 | frameRec.Width <= 0)
return;
//draw the drop shadow using the shadow path rectangle
if (DropShadowVisible)
{
using (GraphicsPath path = GraphicsFunctions.RoundRectangle(shadowRec, _CornerRadius, _Corners))
{
using (SolidBrush b = new SolidBrush(_ShadowColor))
{
e.Graphics.FillPath(b, path);
}
}
}
//draw the rest of the control in the main frame path
using (GraphicsPath path = GraphicsFunctions.RoundRectangle(frameRec, _CornerRadius, _Corners))
{
//paint the background inside the frame
if (BackgroundGradientMode == ControlGradientMode.None)
{
//solid background
using (SolidBrush b = new SolidBrush(BackgroundColor))
{
e.Graphics.FillPath(b, path);
}
}
else
{
//gradient
if (BackgroundGradientMode == ControlGradientMode.VerticalGlow)
{
using (LinearGradientBrush b = new LinearGradientBrush(new Point(0, frameRec.Top + (frameRec.Height / 2)), new Point(0, frameRec.Bottom - 1), BackgroundColorGradient, BackgroundColor))
{
b.WrapMode = WrapMode.TileFlipXY;
e.Graphics.FillPath(b, path);
}
}
else if (BackgroundGradientMode == ControlGradientMode.HorizontalGlow)
{
using (LinearGradientBrush b = new LinearGradientBrush(new Point(frameRec.Left + (frameRec.Width / 2), 0), new Point(frameRec.Right - 1, 0), BackgroundColorGradient, BackgroundColor))
{
b.WrapMode = WrapMode.TileFlipXY;
e.Graphics.FillPath(b, path);
}
}
else
{
using (LinearGradientBrush br = new LinearGradientBrush(frameRec, BackgroundColor, BackgroundColorGradient, (LinearGradientMode)BackgroundGradientMode))
{
e.Graphics.FillPath(br, path);
}
}
//
using (SolidBrush b = new SolidBrush(ForeColor))
{
StringFormat sf = new StringFormat();
//Rectangle textRec = default(Rectangle);
switch (this.TextAlign)
{
case ContentAlignment.BottomCenter:
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Far;
break;
case ContentAlignment.BottomLeft:
sf.Alignment = StringAlignment.Near;
sf.LineAlignment = StringAlignment.Far;
break;
case ContentAlignment.BottomRight:
sf.Alignment = StringAlignment.Far;
sf.LineAlignment = StringAlignment.Far;
break;
case ContentAlignment.MiddleCenter:
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Center;
break;
case ContentAlignment.MiddleLeft:
sf.Alignment = StringAlignment.Near;
sf.LineAlignment = StringAlignment.Center;
break;
case ContentAlignment.MiddleRight:
sf.Alignment = StringAlignment.Far;
sf.LineAlignment = StringAlignment.Center;
break;
case ContentAlignment.TopCenter:
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Near;
break;
case ContentAlignment.TopLeft:
sf.Alignment = StringAlignment.Near;
sf.LineAlignment = StringAlignment.Near;
break;
case ContentAlignment.TopRight:
sf.Alignment = StringAlignment.Far;
sf.LineAlignment = StringAlignment.Near;
break;
}
sf.Alignment = StringAlignment.Center;
e.Graphics.DrawString(this.Text, this.Font, b, (RectangleF)frameRec, sf);
Invalidate();
}
Invalidate();
}
e.Graphics.ResetTransform();
//draw the border
using (Pen p = new Pen(BorderColor, BorderWidth))
{
e.Graphics.DrawPath(p, path);
}
}
}
}
它依赖于此：
[Flags()]
public enum RoundedControlCorners
{
None = 0,
NorthWest = 2,
NorthEast = 4,
SouthEast = 8,
SouthWest = 16,
All = NorthWest | NorthEast | SouthEast | SouthWest,
North = NorthWest | NorthEast,
South = SouthEast | SouthWest,
East = NorthEast | SouthEast,
West = NorthWest | SouthWest
}
public enum ControlGradientMode
{
/// <summary>Specifies no gradient mode.</summary>
None = 4,
/// <summary>Specifies a gradient from upper right to lower left.</summary>
BackwardDiagonal = LinearGradientMode.BackwardDiagonal,
/// <summary>Specifies a gradient from upper left to lower right.</summary>
ForwardDiagonal = LinearGradientMode.ForwardDiagonal,
/// <summary>Specifies a gradient from left to right.</summary>
Horizontal = LinearGradientMode.Horizontal,
/// <summary>Specifies a gradient from top to bottom.</summary>
Vertical = LinearGradientMode.Vertical,
VerticalGlow = 5,
HorizontalGlow = 6
}
public static class GraphicsFunctions
{
public static GraphicsPath RoundRectangle(Rectangle r, int radius, RoundedControlCorners corners)
{
GraphicsPath path = new GraphicsPath();
if (r.Width <= 0 | r.Height <= 0)
return path;
int d = radius * 2;
int nw = ((corners & RoundedControlCorners.NorthWest) == RoundedControlCorners.NorthWest ? d : 0);
int ne = ((corners & RoundedControlCorners.NorthEast) == RoundedControlCorners.NorthEast ? d : 0);
int se = ((corners & RoundedControlCorners.SouthEast) == RoundedControlCorners.SouthEast ? d : 0);
int sw = ((corners & RoundedControlCorners.SouthWest) == RoundedControlCorners.SouthWest ? d : 0);
//path.AddLine(r.Left + nw, r.Top, r.Right - ne, r.Top);
path.AddLine(r.Left + nw, r.Top, r.Right - ne, r.Top);
if (ne > 0)
{
path.AddArc(Rectangle.FromLTRB(r.Right - ne, r.Top, r.Right, r.Top + ne), -90, 90);
}
path.AddLine(r.Right, r.Top + ne, r.Right, r.Bottom - se);
if (se > 0)
{
path.AddArc(Rectangle.FromLTRB(r.Right - se, r.Bottom - se, r.Right, r.Bottom), 0, 90);
}
path.AddLine(r.Right - se, r.Bottom, r.Left + sw, r.Bottom);
if (sw > 0)
{
path.AddArc(Rectangle.FromLTRB(r.Left, r.Bottom - sw, r.Left + sw, r.Bottom), 90, 90);
}
path.AddLine(r.Left, r.Bottom - sw, r.Left, r.Top + nw);
if (nw > 0)
{
path.AddArc(Rectangle.FromLTRB(r.Left, r.Top, r.Left + nw, r.Top + nw), 180, 90);
}
path.CloseFigure();
return path;
}
}
我正在使用的代码将其添加到表单中：
LabelEx oLabel1 = new LabelEx();
LabelEx oLabel2 = new LabelEx();
LabelEx oLabel3 = new LabelEx();
oLabel1.Top = 50;
oLabel2.Top = 100;
oLabel3.Top = 150;
oLabel1.Height = 25;
oLabel2.Height = 25;
oLabel1.Text = "Hello";
oLabel2.Text = "There";
scBase.Panel2.Controls.Add(oLabel1);
scBase.Panel2.Controls.Add(oLabel2);
答案 0 :(得分：5)
protected override void OnPaint(PaintEventArgs e)
{
//...
Invalidate();
}
任何程序员的一个好习惯就是始终运行任务管理器。我总是将它最小化到通知区域。对机器上发生的事情进行鸟瞰，快速点击即可激活它。
很快就发现了你的程序出了什么问题，它正在燃烧100％核心。这是因为您在OnPaint（）方法中调用Invalidate（），会立即使您绘制的内容无效。这有几个副作用，因为你看到你的程序永远不会空闲并继续在处理器核心上运行代码。因为Windows一遍又一遍地生成绘画事件。
另一方面，只有一个标签控件才能被绘制。第一个，Z顺序中最低的。因为在完成绘制之后，由于Invalidate（）调用，下一个绘制请求再次针对相同的标签。
删除Invalidate（）调用以解决您的问题，有两个。