Change value of label in Xcode

I'm new in Xcode. I want to make a Progress View and below is a label. This label can change value from 1 to 100 just the same when the progress run. For example: when i tap the "Start"开发者_JAVA百科 button then the progress run from 1 to 100, so does the label run from 1 to 100. Absolutely, i want to see to value change 1,2,3,4... of the label. Can anyone help me?

Code details attached is good. Thanks!

You can use this logic to get your answer.