将字符串转换为自定义枚举

Question

I'm trying to set a custom enum property on a custom object by looking at a string value that is held in another object, but I keep getting the error "cannot reference a type through an expression."

so far I've tried

rec.Course  = (CourseEnum)Enum.Parse(typeof(CourseEnum), rr.course);

where rec.Course wants a member of the CourseEnum Enumeration, and rr.course is a string.

I also tried to do a switch statement where the value of rr.course is checked (there are only certain values it can be) but get the same result

the enum is defined as follows:

public enum CourseEnum
    {
        [StringValue("Starters")]
        Starters,
        [StringValue("Main Course")]
        MainCourse,
        [StringValue("Desserts")]
        Desserts
    };

public class StringValue : System.Attribute
{
    private string _value;

    public StringValue(string value)
    {
        _value = value;
    }

    public string Value
    {
        get { return _value; }
    }

}

public static class StringEnum
{
    public static string GetStringValue(Enum value)
    {
        string output = null;
        Type type = value.GetType();

        //Check first in our cached results...

        //Look for our 'StringValueAttribute' 

        //in the field's custom attributes

        FieldInfo fi = type.GetRuntimeField(value.ToString());
        StringValue[] attrs =
           fi.GetCustomAttributes(typeof(StringValue),
                                   false) as StringValue[];
        if (attrs.Length > 0)
        {
            output = attrs[0].Value;
        }

        return output;
    }
}

Answer 1

I can see in your code that your using Enum.Parse with CourseEnum and it should be recipeCourse I presume.

I can't spot any place in your sample code where4 CourseEnum is defined.

Answer 2

A @Hans Kesting said, the answer was here: Why can not reference a type through an expression?

The problem was using a field that has an enum type with the enum type itself.