GDI+ 学习记录(29) 区域 - Region

//创建并填充区域
var
g:TGPGraphics;
sb:TGPSolidBrush;
region:TGPRegion;{定义区域}
begin
g:=TGPGraphics.Create(Canvas.Handle);
g.Clear(aclWhite);
sb:=TGPSolidBrush.Create(aclGold);

region:=TGPRegion.Create(MakeRect(20,20,150,150));{建立区域}

g.FillRegion(sb,region);{填充区域}

region.Free;
sb.Free;
g.Free;
end;

//根据路径建立区域
var
g:TGPGraphics;
path:TGPGraphicsPath;
region:TGPRegion;
sb:TGPSolidBrush;
const
pts:array[0..3] of TGPPoint =
((x:10;y:10),
(x:150;y:10),
(x:100;y:75),
(x:100;y:150));

begin
g:=TGPGraphics.Create(Canvas.Handle);
g.Clear(aclWhite);
sb:=TGPSolidBrush.Create(aclRed);
path:=TGPGraphicsPath.Create();
path.AddPolygon(pgppoint(@pts),Length(pts));

region:=TGPRegion.Create(path);//根据路径建立区域
g.FillRegion(sb,region);

region.Free;
path.Free;
sb.Free;
g.Free;

end;

//区域联合
var
g:TGPGraphics;
region:TGPRegion;
sb:TGPSolidBrush;
begin
g:=TGPGraphics.Create(Canvas.Handle);
g.Clear(aclWhite);
sb:=TGPSolidBrush.Create(aclRed);
region:=TGPRegion.Create(MakeRect(60,10,50,150));{建立区域}
region.Union(MakeRect(10,60,160,50));{区域联合}

g.FillRegion(sb,region);{填充}

region.Free;
sb.Free;
g.Free;
end;

//用区域剪切画板
var
g:TGPGraphics;
p:TGPPen;
sb:TGPSolidBrush;
region:TGPRegion;
font:TGPFont;
begin
g:=TGPGraphics.Create(Canvas.Handle);
p:=TGPPen.Create(aclRed);
sb:=TGPSolidBrush.Create(aclYellowGreen);
font:=TGPFont.Create('宋体',12);

region:=TGPRegion.Create(MakeRect(60,0,50,150));{建立区域}
region.Union(MakeRect(10,60,160,50));{区域联合}

g.FillRegion(sb,region);

g.SetClip(region);{用区域剪切画板}

g.DrawLine(p,0,0,100,100);{测试画板剪切后的直线}

sb.SetColor(aclBlack);
g.DrawString('巅枫 巅枫 巅枫 巅枫',-1,font,makepoint(20.0,20.0),sb);{测试文本}

sb.Free;
region.Free;
font.Free;
p.Free;
g.Free;

end;