android Xml生成一条细线

<View
 android:layout_width="match_parent" 
 android:layout_height="2dip"
 android:background="#FF909090" 
 android:layout_marginLeft="40dip"
 android:layout_marginRight="40dip"
 android:layout_marginTop="10dip" />

//android获取屏幕的高度和宽度用到WindowManager这个类，两种方法： 
 //第一种
WindowManager wm = (WindowManager) getContext()
                    .getSystemService(Context.WINDOW_SERVICE);
 
     int width = wm.getDefaultDisplay().getWidth();
     int height = wm.getDefaultDisplay().getHeight();
 //第二种
WindowManager wm = this.getWindowManager();
 
     int width = wm.getDefaultDisplay().getWidth();
     int height = wm.getDefaultDisplay().getHeight();