C# equivalent to Java's Exception.printStackTrace()?

Try this:

Console.WriteLine(ex.ToString());

From http://msdn.microsoft.com/en-us/library/system.exception.tostring.aspx:

The default implementation of ToString obtains the name of the class that threw the current exception, the message, the result of calling ToString on the inner exception, and the result of calling Environment.StackTrace. If any of these members is null, its value is not included in the returned string.

Note that in the above code the call to ToString isn't required as there's an overload that takes System.Object and calls ToString directly.

I would like to add: If you want to print the stack outside of an exception, you can use:

Console.WriteLine(System.Environment.StackTrace);

As Drew says, just converting the exception a string does this. For instance, this program:

using System;

class Test
{
    static void Main()
    {
        try
        {
            ThrowException();
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
        }
    }

    static void ThrowException()
    {

        try
        {
            ThrowException2();
        }
        catch (Exception e)
        {
            throw new Exception("Outer", e);
        }
    }

    static void ThrowException2()
    {
        throw new Exception("Inner");
    }
}

Produces this output:

System.Exception: Outer ---> System.Exception: Inner
   at Test.ThrowException2()
   at Test.ThrowException()
   --- End of inner exception stack trace ---
   at Test.ThrowException()
   at Test.Main()