Use enum from another class?

[JonnyPoet]

....can someone explain why I have to cast to int since there is a reference to the class that contains the enumeration? I would think the cast would be unnecessary.....

When your SetContainerType is like

public void SetContainerType(int type){
.... 
}

Then you need to cast. as you are awaiting an integer here
if instead of this you have

public void SetContainerType(ContainerTypes type){
...
 
}

then this works without troubles. May I ask why you have it this way ?

public class class1
	{
		[FlagsAttribute]
		public enum ContainerTypes : int
		{
			CT_OUTLOOK = 0,
			CT_XML = 1,
			CT_SDX = 2,
			CT_SAP = 4
		};
	}

Instead of this

public enum ContainerTypes : int
		{
			CT_OUTLOOK = 0,
			CT_XML = 1,
			CT_SDX = 2,
			CT_SAP = 4
		};
 
public class class1 {
...whatever needs using your enum here
}

as the enum is public its quite useless to put it into the class, isn't it ? And use singular names for enum as you in every case have one of them.