How do you get the width and height of a multi-dimensional array?

Question

You use Array.GetLength with the index of the dimension you wish to retrieve.

Use GetLength(), rather than Length.

int rowsOrHeight = ary.GetLength(0);
int colsOrWidth = ary.GetLength(1);

// Two-dimensional GetLength example.
int[,] two = new int[5, 10];
Console.WriteLine(two.GetLength(0)); // Writes 5
Console.WriteLine(two.GetLength(1)); // Writes 10

Some of the other posts are confused about which dimension is which. Here's an NUNIT test that shows how 2D arrays work in C#

[Test]
public void ArraysAreRowMajor()
{
    var myArray = new int[2,3]
        {
            {1, 2, 3},
            {4, 5, 6}
        };

    int rows = myArray.GetLength(0);
    int columns = myArray.GetLength(1);
    Assert.AreEqual(2,rows);
    Assert.AreEqual(3,columns);
    Assert.AreEqual(1,myArray[0,0]);
    Assert.AreEqual(2,myArray[0,1]);
    Assert.AreEqual(3,myArray[0,2]);
    Assert.AreEqual(4,myArray[1,0]);
    Assert.AreEqual(5,myArray[1,1]);
    Assert.AreEqual(6,myArray[1,2]);
}