如何在表格中插入行？

Question

我是Objective-c的新手.我有一个包含3行和1个部分的tableView.你能帮我看看如何通过按下按钮(addCity)在表格中添加一些文本行吗？

- (void)viewDidLoad {
    [super viewDidLoad];
    m_bg.image = [UIImage imageNamed:[WeatherAppDelegate isNight]  ? @"SettingsBackNight.png" : @"SettingsBackDay.png" ];
    tableView.layer.cornerRadius = 10;
    m_scrollView.layer.cornerRadius = 10;
    [m_scrollView setContentSize:CGSizeMake(tableView.frame.size.width, tableView.frame.size.height)];
    dataArray = [[NSMutableArray alloc] initWithObjects:@"Moscow", @"London", @"Paris", nil];

}


- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [dataArray count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *MyIdentifier = @"MyIdentifier";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];

    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:MyIdentifier] autorelease];
    }

    [cell.textLabel setText: [dataArray objectAtIndex:indexPath.row]];
    return cell;
}


-(IBAction)addCity:(id)sender
{
    [dataArray addObject:@"City"];
    NSArray *paths = [NSArray arrayWithObject:[NSIndexPath indexPathForRow:[dataArray count]-1 inSection:1]];
    [[self tableView] insertRowsAtIndexPaths:paths withRowAnimation:UITableViewRowAnimationTop];
    [tableView reloadData];
}

Answer 1

您的表必须从某些源中获取其数据,您可以在需要时添加元素.(比如说,数据源中的NSMutableArray实例),那么你的方法就会像.为简单起见,假设您有包含NSStrings的dataArray:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
   return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
   return [dataArray count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
  static NSString *MyIdentifier = @"MyIdentifier";
  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
  if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:MyIdentifier] autorelease];
  }
  [cell.textLabel setText: [dataArray objectAtIndex:indexPath.row];
  return cell;
}


-(IBAction)addCity:(id)sender
{
  [tableView beginUpdates];
  [dataArray addObject:@"City"];
  NSArray *paths = [NSArray arrayWithObject:[NSIndexPath indexPathForRow:[dataArray count]-1 inSection:1]];
  [[self tableView] insertRowsAtIndexPaths:paths withRowAnimation:UITableViewRowAnimationTop];
  [tableView endUpdates];
}