Round off number in C# windows base application

I doubt you really need rounding: it is needed very rarely. I suspect you only need a rounded presentation of the number to be shown on the screen, which is a completely different thing. You really should not round any values before you present them.

Use string.Format with proper precision specifiers.
See:
http://msdn.microsoft.com/en-us/library/system.string.format.aspx[^],
http://msdn.microsoft.com/en-us/library/dwhawy9k.aspx[^],
http://msdn.microsoft.com/en-us/library/0c899ak8.aspx[^].

—SA

What you are looking for is the Math.Round method.

int num = Math.Round(myNumber);

See[^] Math.Round.

double test = 3.4;
int result = Math.Round(test,1,MidpointRounding.AwayFromZero);

Do you mean MidpointRounding.AwayFromZero?

you can refer MSDN abort AwayFromZero:
http://msdn.microsoft.com/en-us/library/system.midpointrounding.aspx[^]