android - The id in different layout xml must be different? -

I have two layout xml file, Main.xml, a button of Android name: id = "@ + id / BtnClose ", and about.xml also has a button named Android: id =" @ + id / btnclose ", is that OK? Thanks!

main.xml

  & lt; Relative layout xmlns: android = "http://schemas.android.com/apk/res / Android" Android: layout_width = "fill_parent" Android: layout_height = "wrap_content" Android: paddingTop = "3dip" Android: layout_marginTop = "3dip "Android: Background =" # DCDCDC "& gt; & Lt; Button android: id = "@ + id / btnClose" style = "@ style / MyTextAppearance" Android: Layout_width = "Wrap_content" Android: Layout_height = "Wrap_content" Android: layout_alignParentRight = "true" android: text = "@ string / out Exit "/> & Lt; / RelativeLayout & gt;   
  about.xml     & lt; LinearLayout xmlns: android = "http://schemas.android.com/apk/sh/Android" xmlns: Advertisement = "http://schemas.android.com/apk/lib/com.google.ads" Android: layout_width Android: layout_height = "fill_parent" Android: paddingTop = "3dip" Android: paddingLeft = "7dip" Android: background = "@ line / boundary_i" Android: orientation = "vertical" & gt; & Lt; Button android: id = "@ + id / btnClose" Android: Layout_width = "Wrap_content" Android: Layout_height = "Wrap_content" Android: Layout_gravity = "center" style = "@ style / MyTextAppearance" android: text = "@ string / Marryren "/> & Lt; / LinearLayout & gt;    
 
 
 it can be the same  
 Illusion / ambiguity Avoid but it is better to have different IDs as suggested by BlackBelt.  
 You can set the current view for hierarchy of the activity. So if you have the same ID in the different XML layout it's okay.  
 If the code you have  
 down <> setContentView (R.layout.main) button b = (Button) findViewById (R.id.btnClose); // start button   
 You are currently visible can ViewById the hierarchy main.xml  
 If you have below  
 < Code> setContentView (R.layout.about); Button B = (button) Find VVBIID (RID. BTN close); // initialize button   
 In both the above cases, both have code containing the button with  main.xml  and  about.xml  < Close the code> @ + ID / BTNC   
 Assume that you get an ID  @ + id / button2  in  about.xml  and another The button is down  
  setContentView (R.layout.main); Button B = (button) Find VVBIID (R.B. button2);   
 You will get  NullPointerException  because your current view is set to the hierarchy activity  main.xml  not  about.xml . There is no button in the  main.xml  with ID  button2 .