use QString::number ( double n, char format = 'g', int precision = 6 )

[lzpmail]

yea, my code is like with you, but the value is not expected, it will change everytime,
this is my code

int fValue;              //fValue will changed in other place
QString mStrContext;
mStrContext = QString::number(fValue/10.0,  'g',  3);
pp.drawText(x, y, mStrContext);

int fValue;              //fValue will changed in other place
QString mStrContext;
mStrContext = QString::number(fValue/10.0,  'g',  3);
pp.drawText(x, y, mStrContext);

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when i use qDebug() print the (fValue/10.0) is also be die.