ios - 删除行前的确认

Question

我试图在实际从 UITableView 中删除单元格之前显示 UIAlertView

NSIndexPath *_tmpIndexPath;


- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if(editingStyle == UITableViewCellEditingStyleDelete)
    {
        _tmpIndexPath = indexPath;

         NSLog(@"%d", indexPath.row); // 2
         NSLog(@"%d", _tmpIndexPath.row); // 2

        UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:@"Dete" message:@"Are you sure you want to delete this entry?" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"Ok", nil] autorelease];
        [alert show];
    }
}

所以我的两个日志都返回了正确的路径。

我有我的观点委托(delegate) UIAlertView

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    NSLog(@"%d", _tmpIndexPath.row);
    if(buttonIndex == 1)
    {
        NSLog(@"%d", _tmpIndexPath.row);
    }
}

现在我无法弄清楚为什么在 clickButtonAtIndex() 中尝试记录 _tmpIndexPath.row 时出现错误

 *** -[NSIndexPath row]: message sent to deallocated instance 0x12228e00

Answer 1

您将需要保留 indexPath，发生的情况是当警报被解除时您的 indexPath 已经从您的系统中释放，

像这样

改变

_tmpIndexPath = indexPath;

到

_tmpIndexPath = [indexPath retain];