C # – How to convert a two-dimensional array into a single array?

I have the following definition of Two-dimensional table:

int[,] arrayBidimensional = new int[3, 3]
{
1, 2, 3
4, 5, 6,
{7, 8, 9}
};

The variable above has no method .ToArray () so that the value is converted into a simple array.

How to convert this table in two dimensions for a int[ ] instead of int[,] ? There is a way simple do that?