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

[Yanhao Zhu]

Thank you so much, Patrick! That fixed the error. Appreciate your help
very much!

--Yanhao

On Thu, Jul 2, 2009 at 1:41 AM, Patrick Vollebregt<jeet.nl at gmail.com> wrote:
> 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
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>> Qt-interest at trolltech.com
>> http://lists.trolltech.com/mailman/listinfo/qt-interest
>>
>
>