I have a function as below:
public var UpdateMapFetcher(int stationID, int typeID)
I need this function to return either string or int.
My return value is set as below
if (finaloutput == "System.String")
{
// param1[i] = Convert.ChangeType(typeID_New.ToString(), typeof(string));
returnvalue = returnvalue.ToString();
return returnvalue;
}
else if (finaloutput == "System.Int32")
{
int a=0;
a = Convert.ToInt32(returnvalue);
return a;
}
How to have either one data type as return value in dynamic environment.
My intuition tells me, that you are trying to convert string value to some type. In that case you can use:
public T UpdateMapFetcher<T>(int stationID)
{
//var someValue = "23";
return (T)Convert.ChangeType(someValue, typeof(T));
}
//then
var typed = UpdateMapFetcher<int>(6);
In case you don't know T, you can use mapping (0-int, 1-string, etc.):
public object UpdateMapFetcher(int stationID, int type)
{
var typeMap = new []{ typeof(int), typeof(string)};
//var someValue = "23";
return Convert.ChangeType(someValue, typeMap[type]);
}
//then
var untyped = UpdateMapFetcher(6, 0/*0 is int*/);
if (untyped.GetType() == typeof(int))
{ /*is int*/
}
Another solution is to use implicit conversions:
public class StringOrInt
{
private object value;
public ValueType Type { get; set; }
public static implicit operator StringOrInt(string value)
{
return new StringOrInt()
{
value = value,
Type = ValueType.String
};
}
public static implicit operator StringOrInt(int value)
{
return new StringOrInt()
{
value = value,
Type = ValueType.Int
};
}
public static implicit operator int(StringOrInt obj)
{
return (int)obj.value;
}
public static implicit operator string(StringOrInt obj)
{
return (string)obj.value;
}
}
public enum ValueType
{
String,
Int
}
And then (simplified):
public static StringOrInt UpdateMapFetcher(int stationID, int typeID)
{
if (typeID == 0)
return "Text";
return 23;
}
private static void Main(string[] args)
{
var result = UpdateMapFetcher(1, 1);
if (result.Type == ValueType.String) { }//can check before
int integer = result;//compiles, valid
string text = result;//compiles, fail at runtime, invalid cast
}
you can return an object. You'd have to subsequently check for types in your consuming method. I assume that won't be a problem in your usecase.
your method signature is therefore:
public object UpdateMapFetcher(int stationID, int typeID)
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