如何通过反射获取类型的所有常量？

Question

如何使用反射获取任何类型的所有常量？

Answer 1

虽然这是一个旧代码：

private FieldInfo[] GetConstants(System.Type type)

{

    ArrayList constants = new ArrayList();

    FieldInfo[] fieldInfos = type.GetFields(

        // Gets all public and static fields

        BindingFlags.Public | BindingFlags.Static | 

        // This tells it to get the fields from all base types as well

        BindingFlags.FlattenHierarchy);

    // Go through the list and only pick out the constants

    foreach(FieldInfo fi in fieldInfos)

        // IsLiteral determines if its value is written at 

        //   compile time and not changeable

        // IsInitOnly determines if the field can be set 

        //   in the body of the constructor

        // for C# a field which is readonly keyword would have both true 

        //   but a const field would have only IsLiteral equal to true

        if(fi.IsLiteral && !fi.IsInitOnly)

            constants.Add(fi);           

    // Return an array of FieldInfos

    return (FieldInfo[])constants.ToArray(typeof(FieldInfo));

}

资源

您可以使用泛型和LINQ轻松将其转换为更清晰的代码：

private List<FieldInfo> GetConstants(Type type)

{

    FieldInfo[] fieldInfos = type.GetFields(BindingFlags.Public |

         BindingFlags.Static | BindingFlags.FlattenHierarchy);

    return fieldInfos.Where(fi => fi.IsLiteral && !fi.IsInitOnly).ToList();

}

或一行：

type.GetFields(BindingFlags.Public | BindingFlags.Static |

               BindingFlags.FlattenHierarchy)

    .Where(fi => fi.IsLiteral && !fi.IsInitOnly).ToList();