在以下C#代码中，输出结果是什么？
using System;
class Program
{
static void Main(string[] args)
{
int[,] matrix = {
{ 1, 2, 3 },
{ 4, 5, 6 },
{ 7, 8, 9 }
};
Transpose(matrix);
for (int i = 0; i < matrix.GetLength(0); i++)
{
for (int j = 0; j < matrix.GetLength(1); j++)
{
Console.Write(matrix[i, j] + " ");
}
Console.WriteLine();
}
}
static void Transpose(int[,] matrix)
{
int n = matrix.GetLength(0);
for (int i = 0; i < n; i++)
{
for (int j = i + 1; j < n; j++)
{
int temp = matrix[i, j];
matrix[i, j] = matrix[j, i];
matrix[j, i] = temp;
}
}
}
}