我正在为 Delphi 使用 Mitov 的 IGDIPlus 库。在完全无辜的情况下，我得到了异常“通用错误”。我有五个重叠的矩形，想用它aPath.outline()来查找轮廓路径（我在 Win7 上运行此示例，应用了所有与轮廓相关的补丁）。
uses
System.Types, IGDIPlus, VCL.IGDIPlusExt;
procedure TForm1.FormPaint(Sender: TObject);
var
AGraphics : IGPGraphics;
APath,aPathO : IGPGraphicsPath;
begin
AGraphics := TIGPGraphics.Create( Canvas );
AGraphics.SmoothingMode := SmoothingModeAntiAlias;
AGraphics.TextRenderingHint := TextRenderingHintAntiAlias;
aPath := TIGPGraphicsPath.create() ;
// this path gives generic error
aPath.addRectangle(73,201,108,96);
// --------the difference----------
aPath.addRectangle(73,292,58,96);
// --------the difference----------
aPath.addRectangle(73,383,108,96);
aPath.addRectangle(177,201,108,96);
aPath.addRectangle(177,383,108,96);
try
aPathO := apath.clone().Outline();
AGraphics.DrawPath(TIGPPen.Create( aclRed,1),
aPathO);
except
on E: Exception do
begin
AGraphics.DrawStringF( e.message,
TIGPFont.Create( 'Microsoft Sans Serif', 16, [ fsBold ] ),
TPointF.Create( 23, 23 ),
TIGPSolidBrush.Create( aclRed ) ) ;
AGraphics.DrawPath(TIGPPen.Create( aclRed,1),
aPath);
end;
end;
aPath.reset();
// this path works fine
aPath.addRectangle(373,201,108,96);
// --------the difference----------
aPath.addRectangle(373,292,108,96);
// --------the difference----------
aPath.addRectangle(373,383,108,96);
aPath.addRectangle(477,201,108,96);
aPath.addRectangle(477,383,108,96);
try
aPathO := apath.clone().Outline();
AGraphics.DrawPath(TIGPPen.Create( aclRed,1),
aPathO);
AGraphics.DrawStringF( 'it works',
TIGPFont.Create( 'Microsoft Sans Serif', 16, [ fsBold ] ),
TPointF.Create( 423, 23 ),
TIGPSolidBrush.Create( aclRed ) ) ;
except
on E: Exception do
begin
AGraphics.DrawStringF( e.message,
TIGPFont.Create( 'Microsoft Sans Serif', 16, [ fsBold ] ),
TPointF.Create( 223, 23 ),
TIGPSolidBrush.Create( aclRed ) ) ;
AGraphics.DrawPath(TIGPPen.Create( aclRed,1),
aPath);
end;
end;
end;
欢迎任何想法，建议。
在 C# 中运行相同的示例会产生相同的错误（在 .Net 中使用带有 GDI+ 的 Outline 路径）
GraphicsPath aPath = new GraphicsPath();
aPath.AddRectangle(new Rectangle(73, 201, 108, 96));
aPath.AddRectangle(new Rectangle(73, 292, 58, 96));
aPath.AddRectangle(new Rectangle(73, 383, 108, 96));
aPath.AddRectangle(new Rectangle(177, 201, 108, 96));
aPath.AddRectangle(new Rectangle(177, 383, 108, 96));
HandleRef handle = new HandleRef(aPath, (IntPtr)aPath.GetType().GetField("nativePath", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(aPath));
try
{
int status = GdipWindingModeOutline(handle, IntPtr.Zero, 0.25F);
using (Pen outlinePen = new Pen(Color.FromArgb(255, Color.Red), 2))
{
g.DrawPath(outlinePen, aPath);
}
}
catch (Exception exp)
{ ...
}
GdipWindingModeOutline函数返回状态=1（一般错误）
因为我确实需要使用轮廓曲线，而直接的方式aPath.clone().outline()是由于gdi +错误不可能，我不得不去arround。合适的解决方案 - 也许不是最好的，但有效 - 可能是：
procedure TForm1.FormPaint(Sender: TObject);
var
AGraphics : IGPGraphics;
APath,aPathO : IGPGraphicsPath;
aRegion : IGPRegion;
aScan : TArray;
aMatrix : IGPmatrix;
begin
AGraphics := TIGPGraphics.Create( Canvas );
AGraphics.SmoothingMode := SmoothingModeAntiAlias;
AGraphics.TextRenderingHint := TextRenderingHintAntiAlias;
aPath := TIGPGraphicsPath.create() ;
aRegion := TIGPRegion.create().MakeEmpty();
aRegion.Union( TIGPRect.create(73,201,108,96));
aRegion.Union( TIGPRect.create(73,292,58,96));
aRegion.Union( TIGPRect.create(73,383,108,96));
aRegion.Union( TIGPRect.create(177,201,108,96));
aRegion.Union( TIGPRect.create(177,383,108,96));
aMatrix := TIGPMatrix.Create();
aScan := lRegion.GetRegionScans(aMatrix);
for i := 0 to High(aScan) do
aPath.addRectangle( GPInflateRect( aScan[i], 1));
aPathO := aPath.Clone().Outline();
AGraphics.DrawPath(TIGPPen.Create( aclRed,1), aPathO);
end;