QDataStream के साथ काम करें

पढ़ो लिखो

sctruct anyStruct { short sVal; float fVal; double dVal; short Empty; char array[8]; } QDataStream operator <<(QDataStream &out, const anyStruct &any) { out << any.sVal; out << any.fVal; out << any.dVal; out << any.Empty; out.writeRawData(any.array,sizeof(any.array)); return out; } 

 QDataStream operator >>(QDataStream &out, anyStruct &any) { out >> any.sVal; out.setFloatingPointPrecision(QDataStream::FloatingPointPrecision); out >> any.fVal; out.setFloatingPointPrecision(QDataStream::DoublePrecision); out >> any.dVal; out.skipRawData(sizeof(any.Empty)); out.ReadRawData(any.array,sizeof(any.array)); return out; } 

 QDataStream operator >>(QDataStream &out, float &val) { if(out. FloatingPointPrecision() != QDataStream:: SinglePrecision) { out.setFloatingPointPrecision(QDataStream::FloatingPointPrecision); out >> val; out.setFloatingPointPrecision(QDataStream::DoublePrecision); } } 

(डी) क्यूटी वर्गों का क्रमिकरण

 #include <QtCore/QCoreApplication> #include <QDataStream> #include <QByteArray> #include <QFile> #include <QString> #include <QHash> #include <QDebug> class simpleClass { public: quint32 a,b; quint32 func(quint32 arg1, quint32 arg2); quint32 getC(); friend QDataStream &operator <<(QDataStream &stream,const simpleClass &sC); friend QDataStream &operator >>(QDataStream &stream, simpleClass &sC); protected: quint32 c; }; inline quint32 simpleClass::func(quint32 arg1, quint32 arg2) { a = arg1; b = arg2; c = a+b; return c; } inline quint32 simpleClass::getC() { return c; } inline QDataStream &operator <<(QDataStream &stream,const simpleClass &sC) // ; { stream << sC.a; stream << sC.b; stream << sC.c; return stream; } inline QDataStream &operator >>(QDataStream &stream, simpleClass &sC) // ; { stream >> sC.a; stream >> sC.b; stream >> sC.c; return stream; } int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); QFile appFile(QString("filename.data")); appFile.open(QFile::Append); //    ; QDataStream inFile(&appFile); //     QIODevice; QHash <quint32,simpleClass> hash; //       ; for(quint32 i = 0; i < 64; i++) { if(!hash.contains(i)) //    ,    ; { simpleClass sC; //  ; sC.func(i,i+10); //   ; hash.insert(i,sC); //   ; } } inFile.setVersion(QDataStream::Qt_4_8); //    Qt,  ; inFile << hash; //  ; appFile.flush(); //     ; appFile.close(); //      ; QFile readFile(QString("filename.data")); readFile.open(QFile::ReadOnly); QDataStream outFile(&readFile); outFile.setVersion(QDataStream::Qt_4_8); QHash<quint32,simpleClass> readHash; //   ; outFile >> readHash; //     ; foreach(quint64 key, readHash.keys()) //   : readHash.keys()    ; { simpleClass sC = readHash.value(key); //     ; qDebug() << "Sum was " << sC.getC(); //   ; qDebug() << "Sum is "<< sC.func(key,2*key); //   ; } readFile.close(); return a.exec(); } 

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