请问QT中有toFloat() 这样的写法吗 [复制链接]

float c = query.value(1).toFloat();
我这样写好像不可以，哪位告诉我该怎么写啊？
QT中如何实现浮点型和字符型的互相转化！

float QString::toFloat ( bool * ok = 0 ) const
Returns the string converted to a float value.
If a conversion error occurs, *ok is set to false; otherwise *ok is set to true. Returns 0.0 if the conversion fails.
Example:
    QString str1 = "1234.56";
    str1.toFloat();            // returns 1234.56

    bool ok;
    QString str2 = "R2D2";
    str2.toFloat(&ok);          // returns 0.0, sets ok to false