how to convert int to uint

Question

I have int variable with value 820924 when I'm trying to convert it like that:

(uint)data[structure["MICROSECONDS"].Index]

it doesn't work.

This doesn't work as well

unchecked((uint)data[structure["MICROSECONDS"].Index])

I receive Specified cast is not valid. exception.

Data stores object, but at run time I should try to convert to int. I'm almost sure. I've printed object value it was 820924, however I don't know how to print object type, but it must be int.

Code:

object value = data[structure["MICROSECONDS"].Index]; Console.WriteLine("xx MICROSECONDS type " + value.GetType()); Console.WriteLine("xx casting " + value); Console.WriteLine("xx cast ok" + (uint)value); 

Result:

xx MICROSECONDS type System.Int32 xx casting 820924 

Answer 1

First of all you should check the type of your value. You can do it by calling obj.GetType() method (either in your code directly or in Immediate window).

If it is int then you can do:

uint u = (uint) (int) obj; 

Please note that it differs from your cast because it casts to int and then converts to uint while you were trying to cast to uint. int cannot be cast to uint and that is why you get the InvalidCastException. int can be only converted to uint. It is confusing that both conversion and cast operators look same in code: u = (uint) x.

Easier thing you can do is calling a specific method from Convert class:

uint u = Convert.ToUInt32(x); 

Answer 2

The problem is that int is stored as object. Int derives from object but uint doesn't derive from int so you can't cast int stored as object to uint. First you have to cast it to int and then to uint because that cast is valid. Try it yourself:

object o = 5;//this is constant that represents int, constant for uint would be 5u uint i = (uint)o;//throws exception 

But this works:

object o = 5; int i = (int)o; uint j = (uint)i; 

or

object o = 5; uint i = (uint)(int)o; //No matter how this looks awkward