ios7屏幕适配

第一步 在项目的Info.plist 文件中 添加一行属性配置
View controller-based status bar appearance ＝NO
这个设置为：View Controller 不对status Bar 显示进行操作

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7) {          

      [application setStatusBarStyle:UIStatusBarStyleLightContent];            

     self .window.clipsToBounds = YES ;              

   self .window.frame =  CGRectMake(0,20, self .window.frame.size.width, self .window.frame.size.height-20);

         //added on 19th Sep

         self .window.bounds = CGRectMake(0, 20, self .window.frame.size.width, self .window.frame.size.height);

     }

http://stackoverflow.com/questions/18294872/ios-7-status-bar-back-to-ios-6-style