[Qt-interest] QPainter.drawText on windows: Access violation

[Patrick Vollebregt]

Hi,

Change QCoreApplication in QApplication and it should work. Maybe 
(haven't really looked into it) some initialization regarding palettes 
is done in QApplication, which isn't in QCoreApplication.

Kinds regards,

Patrick.
> Hi, all,
>
> I keep getting [Access violation] error with QPainter::drawText method
> on windows. Here is the very simple code I used:
>
> -------------------------------------------------------------
> #include <QtCore/QCoreApplication>
> #include <QImage>
> #include <QPainter>
> #include <QFont>
>
> int main(int argc, char *argv[])
> {
>     QCoreApplication a(argc, argv);
>
>     QFont font("Lucida Console", 16);
>
>     QImage image(256, 256, QImage::Format_ARGB32);
>
>     QPainter painter(&image);
>     painter.setFont(font);
>     painter.drawText(10, 100, "Hello, world!");
>
>     image.save("test.png", "PNG");
>
>     //return a.exec();
> }
> ------------------------------------
>
> The following is the partial call stack:
> QtCored4.dll!QBasicAtomicInt::ref()  Line 257 + 0x8 bytes	C++
> QtGuid4.dll!QColormap::QColormap()  Line 145 + 0x1d bytes	C++
> QtGuid4.dll!QColormap::instance(int __formal=-1)  Line 141 + 0x13 bytes	C++
> QtGuid4.dll!QNativeImage::systemFormat()  Line 138 + 0xb bytes	C++
> QtGuid4.dll!QFontEngineWin::drawGDIGlyph(HFONT__ * font=0x2e0a0446,
> unsigned int glyph=85, int margin=0, const QTransform & t={...})  Line
> 1411 + 0x29 bytes	C++
> QtGuid4.dll!QFontEngineWin::alphaMapForGlyph(unsigned int glyph=85,
> const QTransform & xform={...})  Line 1452 + 0x19 bytes	C++
> QtGuid4.dll!QImageTextureGlyphCache::fillTexture(const
> QTextureGlyphCache::Coord & c={...}, unsigned int g=85)  Line 227 +
> 0x36 bytes	C++
> QtGuid4.dll!QTextureGlyphCache::populate(const QTextItemInt &
> ti={...}, const QVarLengthArray<unsigned int,256> & glyphs={...},
> const QVarLengthArray<QFixedPoint,256> & __formal={...})  Line 143	C++
> QtGuid4.dll!QRasterPaintEngine::drawCachedGlyphs(const QPointF &
> p={...}, const QTextItemInt & ti={...})  Line 2925	C++
> QtGuid4.dll!QRasterPaintEngine::drawTextItem(const QPointF & p={...},
> const QTextItem & textItem={...})  Line 3125	C++
> QtGuid4.dll!QPainter::drawTextItem(const QPointF & p={...}, const
> QTextItem & _ti={...})  Line 6123	C++
> QtGuid4.dll!QPainter::drawText(const QPointF & p={...}, const QString
> & str={...}, int tf=0, int justificationPadding=0)  Line 5680	C++
> QtGuid4.dll!QPainter::drawText(const QPointF & p={...}, const QString
> & str={...})  Line 5618	C++
> QtGuid4.dll!QPainter::drawText(int x=10, int y=100, const QString &
> s={...})  Line 910	C++
>
>
> The same code worked fine in Mac OS X. Any idea why it did not work on
> windows? Did I miss something?
>
> I am using qt 4.5.1 on window with visual c++.
>
>
> Thank you so much,
>
> Yanhao Zhu
> _______________________________________________
> Qt-interest mailing list
> Qt-interest at trolltech.com
> http://lists.trolltech.com/mailman/listinfo/qt-interest
>