In C# Visual Studio, has Text Box, and Button

Create a function that accepts a positive integer and returns an integer array of that length that contains random integers between 200 and 900. Use your function from #3 to reverse that array. Then create a third function that accepts that reversed array and returns a string containing a string representation of the integers in that array separated by spaces (do not use any builtin gadget to convert the integer array into a string. I am expecting loops and math and ascii code here.)