iphone - 如何无条件地将绿色添加图标放在插入行上

Question

我有一个 UITableView，在末尾有一个特殊的行来插入一个新项目。这行得通，但我希望它有绿色加号图标，而不必将表格 View 置于编辑模式。我该怎么做？

如果可能的话，我不希望创建按钮或捆绑图像。有什么方法可以仅使用标准的 UITableView/UITableViewCell 功能来完成其中一项或两项工作吗？

Answer 1

您想将 accessoryView 设置为单元格:

@interface RootViewController : UITableViewController {
  NSInteger nextValue;
  NSMutableArray *timeIntervals;
}


@implementation RootViewController


- (NSNumber *)nextValue {
  NSNumber *n = [NSNumber numberWithInteger:nextValue];
  nextValue++;
  return n;
}

- (void)viewDidLoad {
  [super viewDidLoad];
  nextValue = 1;
  timeIntervals = [[NSMutableArray alloc] init];
  [timeIntervals addObject:[self nextValue]];
}

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

- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"TimeIntervalCell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
                                       reuseIdentifier:CellIdentifier] autorelease];
      UIButton *b = [UIButton buttonWithType:UIButtonTypeContactAdd];
      [b addTarget:self action:@selector(addTapped:) forControlEvents:UIControlEventTouchUpInside];
      cell.accessoryView = b;
    }

  NSNumber *number = [timeIntervals objectAtIndex:indexPath.row];
  cell.accessoryView.tag = indexPath.row;
  cell.textLabel.text = [number stringValue];
  cell.detailTextLabel.text = @"detail about this number";
  return cell;
}

- (void)addTapped:(UIButton *)sender {
  id cell = sender;
  while (cell != nil && [cell isKindOfClass:[UITableViewCell class]] == NO)
    cell = [cell superview];

  if (cell == nil) {
    NSLog(@"[%@ %@] sender was not in a cell", 
          NSStringFromClass([self class]), NSStringFromSelector(_cmd));
    return;
  }

  NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
  NSInteger index = indexPath.row + 1; // insert after current cell
  [timeIntervals insertObject:[self nextValue] atIndex:index];
  NSIndexPath *newIndexPath = [NSIndexPath indexPathForRow:index inSection:0];
  [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
                        withRowAnimation:UITableViewRowAnimationFade];
}


- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
  NSLog(@"[%@ %@] not implemented", NSStringFromClass([self class]), NSStringFromSelector(_cmd));
}


@end

(这是对 Xcode 4.0.2 导航应用程序模板的所有修改代码)