How to set Index and item corresponding to the picker?

I am facing an issue that i can't bind both index and item to the picker respectively. My need is I want to see some items in the Picker and also i want to set the index value to the picker respectively to the items that bind,

i am using pickersg.Items.Add(//some items here); and it is working , but the issue is there is need to update at that case ,passing the value corresponding to the items added