QMetaEnum
包含将枚举索引转换为实际值的方法:
int value(int index) const
但是如何将索引转换回索引
int index(int value) const
?
使用以下功能:
int indexFromValue(const QMetaEnum & e, int value){
for(int ix=0; ix< e.keyCount(); ix++){
if(e.key(ix) == e.valueToKey(value))
return ix;
}
return -1;
}
示例:
#include <QCoreApplication>
#include <QMetaEnum>
#include <QObject>
class Foo : public QObject
{
Q_OBJECT
public:
using QObject::QObject;
enum class FooEnumType { TypeA=10, TypeB=21 };
Q_ENUM(FooEnumType)
};
static int indexFromValue(const QMetaEnum & e, int value){
for(int ix=0; ix< e.keyCount(); ix++){
if(e.key(ix) == e.valueToKey(value))
return ix;
}
return -1;
}
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
const QMetaObject &mo = Foo::staticMetaObject;
int index = mo.indexOfEnumerator("FooEnumType");
QMetaEnum metaEnum = mo.enumerator(index);
Q_ASSERT(indexFromValue(metaEnum, 10) == 0);
Q_ASSERT(indexFromValue(metaEnum, 21) == 1);
Q_ASSERT(indexFromValue(metaEnum, 100) == -1);
return 0;
}
#include "main.moc"