Checking for winner in TicTacToe?

Question

What would be the best way to see (in a 2 player) game of Tic Tac Toe who won? Right now I'm using something similar to the following:

if (btnOne.Text == "X" && btnTwo.Text == "X" && btnThree.Text == "X")
{
    MessageBox.Show("X has won!", "X won!");
    return;
}
else
// I'm not going to write the rest but it's really just a bunch
// if statements.

So how do I get rid of the multiple if's?

Answer 1

Something alongs:

rowSum == 3 || columnSum == 3 || diagnolSum == 3

.. ?