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" />

转载http://www.cnblogs.com/henryxu/archive/2013/04/10/3012081.html

//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();