C#怎么写一个圆形或者椭圆型的自定义控件

开发的新的控件，一般继承自Control，重写OnPaint方法；还要自己写添加事件、处理消息等等。这样的控件，对应你的业务可以达到很好的效果，功能最灵活。同时对开发人员要求也最高，一般要了解图形绘制GDI+以及API的一些知识。比如，我们需要一个类似Label的控件，但是不需要Label那么多的属性和方法。那么就自己开发一个类似Label的自定义控件。

如下代码：直接继承自Control，其它代码会自动生成好。

[csharp] view plaincopyprint?

[ToolboxItem(true)]

public partial class CustomClassifyLabelItem : Control

{

private Color mColorOut = Color.FromArgb(255, 137, 37);

private StringFormat format;

private Color textColor;

private Font strFormat = new Font("宋体", 9F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(134)));

public StringFormat Format

{

get

{

if (format == null)

{

format = new StringFormat();

format.Alignment = StringAlignment.Center;

format.LineAlignment = StringAlignment.Center;

format.FormatFlags = StringFormatFlags.NoWrap;

format.Trimming = StringTrimming.EllipsisCharacter;

}

return format;

}

}

public Color TextColor

{

get

{

{

textColor = Color.FromArgb(22, 95, 162);

}

return textColor;

}

}

public CustomClassifyLabelItem()

{

InitializeComponent();

this.MouseEnter += new EventHandler(UCSelectClassifyItem_MouseEnter);

this.MouseLeave += new EventHandler(UCSelectClassifyItem_MouseLeave);

}

void UCSelectClassifyItem_MouseLeave(object sender, EventArgs e)

{

strFormat = new Font("宋体", 9F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(134)));

Invalidate();

}

void UCSelectClassifyItem_MouseEnter(object sender, EventArgs e)

{

strFormat = new Font("宋体", 12F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(134)));

Invalidate();

}

protected override void OnPaint(PaintEventArgs pe)

{

base.OnPaint(pe);

Graphics graphics = pe.Graphics;

using (SolidBrush b = new SolidBrush(TextColor))

{

graphics.DrawString(this.Text, strFormat, b, new Rectangle(0, 0, this.Width, this.Height), Format);

}

graphics.Dispose();

}

}