Question about arrays in C#

I have

string[] filenames = Directory.GetFiles(@"C:\temp\test", "*.png", SearchOption.AllDirectories);

string[] myArr = new string[10];

private void btnLoadTrainingData_Click(object sender, EventArgs e)
{
            foreach (string f in filenames)
            {                
                img = (Bitmap)Bitmap.FromFile(f);
                Console.WriteLine(convertToBinary(img));            
            }
}

The method 'convertToBinary' returns a string value of 1's and 0's of the converted image.

What I need is how to store the string of each returned value in an array + the filename.

I want something like this:
A_001.png 100100011
A_002.png 100110011
B_001.png 001110111
etc



I have tried to implement an array (see below) but I am always getting the last file that was opened.

private void populateArray(string binVal)
    {
        for (int j = 0; j < myArr.Length; j++)
        {
            //for (int j = 0; j < 2; j++)
            myArr[j] = (binVal);
        }

Tags: C#