Write in C#

Write a method called IsUnique that accepts an array of integers and returns a boolean indicating that each value in the array is unique. Basically, there are no 2 values that are equal.

Example: array { 8, 12, 4, 6, 5, 11, 12, 4, 3} should return false because there are two elements that are equal (12)

However array { 8, 12, 4, 6, 5, 11, 19, 7, 3} is unique, no element is repeated, and should return true

The array should not be sorted.