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uiTableView单元格-是否从按钮获取indexPath.row?

selector uibutton uitableview objective-c iphone

6

dpigera · 技术社区 · 16 年前

我目前在一个单元格中定义了一个按钮,并有一个方法来跟踪它的uitouchdown操作,如图所示:

- (void) clickedCallSign:(id)sender {

    int index = [sender tag];
    NSLog(@"event triggered %@",index);

}

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
    //Callsign button
    UIButton *button;

    CGRect rect = CGRectMake(TEXT_OFFSET_X, BORDER_WIDTH, LABEL_WIDTH, LABEL_HEIGHT);
    button = [[UIButton alloc] initWithFrame:rect];
    cell.tag=[indexPath row];
    button.tag=[indexPath row];
    [button addTarget:self action:@selector(clickedCallSign:) forControlEvents:UIControlEventTouchDown];
    [button setBackgroundColor:[UIColor redColor]];
    [button setTitle:@"hello" forState:UIControlStateNormal];
    [cell.contentView addSubview:button];
    [button release];   
}

但是,当我单击模拟器中的一个单元时,控制台调试消息是:“事件触发(空)”,我的应用程序很快就会崩溃。

如何将indexPath.row值正确获取到ClickedCallSign方法中?

3 回复 | 直到 12 年前

1

2

Ben Zotto sberry 16 年前

首先, index 是一个 int ,因此您的nslog需要如下所示(请注意 %d ):

NSLog(@"event triggered %d", index);

(这是 可能的 这会导致撞车,但也有可能是其他事情导致了不稳定。)

2

JastinBall 12 年前

在没有节和行之前,标记是很好的。尝试其他方法获取索引路径:

- (void)tableView:(UITableView*)tableView willDisplayCell:(UITableViewCell*)cell forRowAtIndexPath:(NSIndexPath*)indexPath {

    //...

    [button addTarget:self action:@selector(clickedCallSign:withEvent:) forControlEvents:UIControlEventTouchDown];

    //...

}

// Get the index path of the cell, where the button was pressed
- (NSIndexPath*)indexPathForEvent:(id)event
{
    NSSet *touches = [event allTouches];
    UITouch *touch = [touches anyObject];
    CGPoint currentTouchPosition = [touch locationInView:self.tableView];
    return [self.tableView indexPathForRowAtPoint:currentTouchPosition];
}

- (IBAction)clickedCallSign:(id)sender withEvent:(UIEvent*)event
{
    NSIndexPath* buttonIndexPath = [self indexPathForEvent:event];
}

3

2

mahboudz 12 年前

如果不想使用标记字段,请让按钮调用此方法:

- (void)tapAccessoryButton:(UIButton *)sender
{
    UIView *parentView = sender.superview;

    // the loop should take care of any changes in the view heirarchy, whether from
    // changes we make or apple makes.
    while (![parentView.class isSubclassOfClass:UITableViewCell.class])
        parentView = parentView.superview;

    if ([parentView.class isSubclassOfClass:UITableViewCell.class]) {
        UITableViewCell *cell = (UITableViewCell *) parentView;
        NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
        [self tableView:self.tableView accessoryButtonTappedForRowWithIndexPath:indexPath];
    }
}