CODEWITHSUNDEEP
c#reflectionenums
rookie
rookie

Reputation: 2913

Casting PropertyInfo.PropertyType to enum

I have a generic function to create objects from a DataRow using reflection. I'm using this function to import tables from an Access database:

private static T CreateItemFromRow<T>(DataRow row, IList<PropertyInfo> properties) where T : new()
{
    T item = new T();
    foreach (var prop in properties)
    {
        try
        {
            if (prop.PropertyType.IsEnum)
                prop.SetValue(item, row[prop.Name], null); // what to do??
            else
                prop.SetValue(item, row[prop.Name], null);
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.Assert(false, string.Format("failed to assign {0} a value of {1}", prop.Name, row[prop.Name]));
        }
    }
    return item;
}

The problem I'm running into is when the property type is an enum. I've tried using Enum.Parse, but that hasn't been successful (I can't get anything to compile).

Is there any way to convert the object represented by row[prop.Name] to the correct enum using my function? Or do I need to write a special conversion function specific for the enums I've defined.

Edit: I am getting

"the type or namespace prop could not be found. Are you missing an assembly directive or reference" compile error for the following:

var val = (prop.PropertyType)Enum.Parse(typeof(prop.PropertyType), row[prop.Name].ToString());

Upvotes: 3

Views: 3601

Answers (2)

Paresh Maghodiya
Paresh Maghodiya

Reputation: 218

My class is like this 

public enum Status
{
    Active,
    Deactive
}

public class Sample
{
    public long Id{ get; set; }
    public string Name{ get; set; }
    public Status UserStatus{ get; set; }
}

In database i stored Status="Active" as string. I used your solution, but got following error

System.ArgumentException: 'The value passed in must be an enum base or an underlying type for an enum, such as an Int32. Parameter name: value'

Upvotes: 0

Trevor Pilley
Trevor Pilley

Reputation: 16393

The reason for the type or namespace prop could not be found exception you were getting is because you cannot cast to a type in this way (prop.PropertyType)Enum.Parse(typeof(prop.PropertyType) - you can only do that where you know the type at compile time - (SomeEnum)Enum.Parse(typeof(SomeEnum).

The correct way to do it is to get the enum value before setting the property value:

prop.SetValue(item, Enum.ToObject(prop.PropertyType, row[prop.Name]), null);

Upvotes: 4

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