c# - Close WPF window that host Pages -

im learning c# wpf. im trying understand how navigation works.

i have created test app includes 2 buttons. 1 navigates next page , open new window.

navigation between pages not problem. able navigate page1 page2 using button. code below written in page1.xaml.cs

private void button_click(object sender, routedeventargs e)     {         page2 p2 = new page2();         this.navigationservice.navigate(p2);     } 

the problem when try open new window , close previous 1 button, doesnt work. (i wrote on page1.xaml.cs)

private void button_copy_click(object sender, routedeventargs e)     {         window1 win1 = new window1();         win1.show();         this.close();     } 

its giving me error code cs1061 , telling me not contain definition 'close' .....

here complete code of page1.xaml.cs:

using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.windows; using system.windows.controls; using system.windows.data; using system.windows.documents; using system.windows.input; using system.windows.media; using system.windows.media.imaging; using system.windows.navigation; using system.windows.shapes;  namespace wpfapplication1 {     /// <summary>     /// interaction logic page1.xaml     /// </summary>     public partial class page1 : page     {         public page1()         {             initializecomponent();         }          private void button_click(object sender, routedeventargs e)         {             page2 p2 = new page2();             this.navigationservice.navigate(p2);         }          private void button_copy_click(object sender, routedeventargs e)         {             window1 win1 = new window1();             win1.show();             this.close();         }     } } 

it's bit of guess, haven't seen enough of code. if call this.close() placed outside class defining window you're trying close, there's no such method in scope of this.