备注一下，方便查阅

WindowManager m = getWindowManager();    
       Display d = m.getDefaultDisplay();  //为获取屏幕宽、高    
       LayoutParams p = getWindow().getAttributes();  //获取对话框当前的参数值    
       p.height = (int) (d.getHeight() * 1.0);   //高度设置为屏幕的1.0   
       p.width = (int) (d.getWidth() * 0.7);    //宽度设置为屏幕的0.8   
       p.alpha = 1.0f;      //设置本身透明度  
       p.dimAmount = 0.0f;      //设置黑暗度  
       getWindow().setAttributes(p);   
用fragment + fragmentTabHost
http://bbs.csdn.net/topics/390074704
http://blog.csdn.net/wa991830558/article/details/39180909  讲解

安卓改变窗体的大小