Unable to convert String to Double[]

I didn't do it all in one operation, but this code does what you ultimately want to achieve:
    String numbers = "100,200,300,400";
    String[] numberInStringArray = numbers.Split(',');
    double[] arrayOfDouble = new double[numberInStringArray.Length];

    for (int i = 0; i < numberInStringArray.Length; i++)
        arrayOfDouble[i] = Convert.ToDouble(numberInStringArray[i]);

    // view our efforts:
    for (int i = 0; i < numberInStringArray.Length; i++)
        Console.Write(arrayOfDouble[i] + " ");