ios7 constructing headers and footers in tableview

static NSString *CellIdentifier = @"CellIdentifier";

@interface  () <UITableViewDelegate, UITableViewDataSource>
@property (nonatomic, strong) UITableView *myTableView;
@end

@implementation 



- (CGFloat)     tableView:(UITableView *)tableView
 heightForHeaderInSection:(NSInteger)section{
    
    if (section == 0){
        return 30.0f;
    }
    
    return 0.0f;
}

//设置footer，section0时为30
- (CGFloat)     tableView:(UITableView *)tableView
 heightForFooterInSection:(NSInteger)section{
    
    if (section == 0){
        return 30.0f;
    }
    
    return 0.0f;
    
}

//header标题
- (NSString *) tableView:(UITableView *)tableView
 titleForHeaderInSection:(NSInteger)section{
    
    if (section == 0){
        return @"Section 1 Header";
    }
    
    return nil;
    
}

//footer标题
- (NSString *) tableView:(UITableView *)tableView
 titleForFooterInSection:(NSInteger)section{
    
    if (section == 0){
        return @"Section 1 Footer";
    }
    
    return nil;
    
}

//Returns the table cell at the specified index path.
- (UITableViewCell *) tableView:(UITableView *)tableView
          cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    
    UITableViewCell *cell = nil;
    cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier
                                           forIndexPath:indexPath];
    cell.textLabel.text = [[NSString alloc] initWithFormat:@"Cell %ld",
                             (long)indexPath.row];
    return cell;
    
}

//3rows in section
- (NSInteger) tableView:(UITableView *)tableView
  numberOfRowsInSection:(NSInteger)section{
    return 3;
}


//iOS7电池状态栏 样式
-(UIStatusBarStyle)preferredStatusBarStyle
{
    return UIStatusBarStyleLightContent;
}

-(void)viewWillLayoutSubviews{
    //iOS7，UIScreen下降20像素，显示黑色电池栏
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7) {
        self.view.clipsToBounds = YES;
        CGRect screenRect = [[UIScreen mainScreen] bounds];
        CGFloat screenHeight = screenRect.size.height;
        self.view.frame =  CGRectMake(0, 20, self.view.frame.size.width,screenHeight-20);
        self.view.bounds = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
    }
}

- (void)viewDidLoad{
    [super viewDidLoad];
    //使用布局，显示扩展边缘
    self.edgesForExtendedLayout = UIRectEdgeNone;
    //初始化tableview，style为group类型
    self.myTableView = [[UITableView alloc] initWithFrame:self.view.bounds
                                 style:UITableViewStyleGrouped];
    //注册cell类
    [self.myTableView registerClass:[UITableViewCell class]
             forCellReuseIdentifier:CellIdentifier];
    
    //datasource，delegate指向ViewController
    self.myTableView.dataSource = self;
    self.myTableView.delegate = self;
    //自动调整布局
    self.myTableView.autoresizingMask = UIViewAutoresizingFlexibleWidth |
    UIViewAutoresizingFlexibleHeight;
    //添加到view
    [self.view addSubview:self.myTableView];
    
}

@end