Qt：没有元数据meta.enumeratorCount（）对于Q_OBJECT中的枚举，为什么？ [英] Qt: No metadata by meta.enumeratorCount() for enum in Q_OBJECT, why?

问题描述

我有以下类，其中我尝试获取一些枚举MyEnum 的元数据。然而，当循环 meta.enumeratorCount（）它的计数总是0.基本上我是以下此示例此处。为了找到问题，我试着和方法一样，同样的问题 - 方法计数0.代码编译，没有错误没有警告。

I have the following class, where I try to obtain some metadata of an enum MyEnum. However, when looping over meta.enumeratorCount() its count is always 0. Basically I was follwing this example here. In order to find the problem, I was trying the same with methods too, same problem - method count 0. Code compiles, no errors no warnings.

必须是一个愚蠢的错误....也许你可以帮助我

Must be a silly mistake .... maybe you can help me

class FsxSimConnectQtfier : public QObject
{
    Q_OBJECT
public:
    explicit FsxSimConnectQtfier(QObject *parent = 0);
    enum MyEnum { G1, G2 };
    static const QString simConnectExceptionToString(const DWORD id);
};

const QString FsxSimConnectQtfier::simConnectExceptionToString(const DWORD id) {
    // int i= FsxSimConnectQtfier::staticMetaObject.indexOfEnumerator("MyEnum");
    // -1 -> not found, why?
    QMetaObject meta = FsxSimConnectQtfier::staticMetaObject;
    for (int i=0; i < meta.enumeratorCount(); ++i) {
        QMetaEnum m = meta.enumerator(i); // never reached, why?
    }
    return "";
}

推荐答案

与元数据系统使用 Q_ENUMS（）宏：

You need to register the enum with the metadata system using the Q_ENUMS() macro:

class FsxSimConnectQtfier : public QObject
{
    Q_OBJECT
    Q_ENUMS(MyEnum)  // <--- 

public:
    explicit FsxSimConnectQtfier(QObject *parent = 0);
    enum MyEnum { G1, G2 };
    static const QString simConnectExceptionToString(const unsigned int id);
};

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