我发现使用GDI绘制圆角矩形的每个示例代码都是这样的(从BobPowell.net解除并略微修改)：
Private Sub Panel1_Paint(ByVal sender As Object,ByVal e As PaintEventArgs) Handles Panel1.Paint
e.Graphics.Clear(SystemColors.Window)
e.Graphics.SmoothingMode = SmoothingMode.None
Call DrawRoundRect(e.Graphics,Pens.Red,10,48,24,6)
End Sub
Public Sub DrawRoundRect(ByVal g As Graphics,ByVal p As Pen,ByVal x As Single,ByVal y As Single,ByVal width As Single,ByVal height As Single,ByVal radius As Single)
Using gp As New GraphicsPath()
gp.StartFigure()
gp.AddArc(x + width - radius,y,radius * 2,270,90)
gp.AddArc(x + width - radius,y + height - radius,90)
gp.AddArc(x,90,180,90)
gp.CloseFigure()
g.DrawPath(p,gp)
End Using
End Sub
这会产生一个圆角矩形,其中只有左上角是准确的.
AntiAliasing必须关闭,因为它正在通过远程桌面连接,我不能依赖它可用.此外,我正在寻找一个清晰的圆角矩形.
我已经尝试调整其他角落的大小并更改笔对齐,但似乎没有任何东西可以产生简单,精确的圆角矩形.
有没有办法在旧的winforms中绘制比这更好的圆角矩形？
1)将源图像的大小调整为其原始大小的二进制倍数.通常,我将重新采样到比原始宽度和高度大4倍(或8或16)的宽度和高度.
2)执行我的所有GDI绘图操作(当然,考虑到我的坐标需要乘以4倍).没有必要使用任何花哨的抗锯齿.
3)将图像重新采样回原始尺寸.缩小图像会产生良好的平滑效果,并最大限度地减少线条,曲线等中的任何舍入误差.
private Bitmap GenerateButton(int overSampling) {
int overSampling = 8;
int width=(48 + 10 + 10 + 6) * overSampling;
int height=(24 + 10 + 10 + 6) * overSampling;
// Draw the button with the rounded corners,but do
// so at 8 times the normal size.
Bitmap bitmap=new Bitmap(width,height);
using (Graphics g = Graphics.FromImage(bitmap)) {
g.Clear(Color.White);
g.SmoothingMode = SmoothingMode.None;
DrawRoundRect(overSampling,g,new Pen(Color.Red,overSampling),6);
}
// Shrink the image down to its intended size
Bitmap shrunkVersion=new Bitmap(bitmap.Width / overSampling,bitmap.Height / overSampling);
using (Graphics g = Graphics.FromImage(shrunkVersion)) {
// Use hi-quality resampling for a nice,smooth image.
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(bitmap,shrunkVersion.Width,shrunkVersion.Height);
}
return shrunkVersion;
}
private void DrawRoundRect(int overSampling,Graphics g,Pen p,float x,float y,float width,float height,float radius)
{
using (GraphicsPath gp = new GraphicsPath())
{
gp.StartFigure();
gp.AddArc((x + width - radius) * overSampling,y * overSampling,(radius * 2) * overSampling,90);
gp.AddArc((x + width - radius) * overSampling,(y + height - radius) * overSampling,90);
gp.AddArc(x * overSampling,radius * 2 * overSampling,90);
gp.CloseFigure();
g.DrawPath(p,gp);
}
}
没有过采样：
进行8次过采样：