在ios7及以上系统中在UINavigationBar中添加UITextField或者UISearchbar时不显示输入光杆问题及解决
-(void)initSearchBar{_textSearch=[[UISearchTextFiledalloc]initWithFrame:CGRectMake(0,7,ScreenWidth-50,30)];_textSearch.placeholder=@"在此输入查找内容";_textSearch.leftView=[[UIImageViewalloc]initWithImage:[UI