how to update gridview when form is close

i have one wpf applicatio in my application i have 1 home page where inside home page i have 4 tab so in 1st tab i have 1 gridview and 1 button so i click on button so 1 new form is open in top of home page so i want when i close my new form then auto refresh my gridview how can i done this please help me... i am using wpf c#