滚动时表视图返回错误值 [英] Table view return wrong values when scrolling

问题描述

问题是我已经实现了一个带有故事板自定义单元格的表格视图.每个单元格都有一个按钮作为选择按钮，这意味着每当我按下按钮时，图像就会改变.例如，如果我按下单元格索引 = 0 的按钮，它的图像会正确更改，但是在滚动表格时我发现其他按钮也更改了它们的图像！问题来自表索引路径，我花了很多时间试图修复它但没有结果.有什么解决办法吗?

The problem is that I have implemented a table view with custom cell from storyboard. Each cell has a button as a selection button which mean whenever I press on a button , it image change. For example, if I press on the button with cell index=0, it image change correctly however when scrolling the table I found other buttons also changed their images! The problem is from the table index path and I spent a lot of time trying to fix it with no result. Any Solution?

    static NSString *simpleTableIdentifier = @"cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    if (cell == nil) {

        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:simpleTableIdentifier];
        NSLog(@"index path inside cell = nil %i",(int)indexPath);
    }

    buttonObj=(UIButton *)[cell viewWithTag:40];
   [buttonObj addTarget:self action:@selector(select:) forControlEvents:UIControlEventTouchDown];

return cell;

-(void) select:(id)sender{
    UIButton *button=(UIButton *)sender;

    UITableViewCell *clickedCell = (UITableViewCell*)[[sender superview] superview];
    NSIndexPath *indexPathCell = [addFriendTableView indexPathForCell:clickedCell];

    NSLog(@"indexPathCell %i",(int)indexPathCell.row);

        Contacts* selectedContact = [contactsArray objectAtIndex:indexPathCell.row];

        if([self image:button.imageView.image isEqualTo:[UIImage imageNamed:@"addFriend.png"]]==YES){

    [button setImage:[UIImage imageNamed:@"addFriendPressed.png"] forState(UIControlStateNormal)];
     [selectFriendsArray addObject:selectedContact];
           counter++
        }

        else if( [self image:button.imageView.image isEqualTo:[UIImage imageNamed:@"addFriendPressed.png"]]==YES)
        {
            [button setImage:[UIImage imageNamed:@"addFriend.png"] forState:(UIControlStateNormal)];
            counter--;
            [selectFriendsArray removeObject:selectedContact];
            }

推荐答案

这里你要做的是为每个单元格获取相同的 UIButton 对象.您需要为每个单元格创建一个单独的按钮.

Here what you are doing is getting same UIButton object for every cell. You need to create a separate button for every cell.

用唯一的标签标识这个 UIButton 对象，然后进一步选择该单元格.

Identify this UIButton object with unique tag and then select that cell for further.

为 UIButton 对象创建一个标签.在 #import statments

Create a tag for UIButton object. Put below line at top of your view controller class after #import statments

#define kButtonTag 1000

现在为每个对象设置唯一的标签.

Now set unique tag for each object.

 static NSString *simpleTableIdentifier = @"cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    if (cell == nil) {

        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:simpleTableIdentifier];
        NSLog(@"index path inside cell = nil %i",(int)indexPath);
    }

    // kButtonTag = 1000

     NSInteger btnTag = kButtonTag + indexPath.row;

     [[cell.contentView viewWithTag:btnTag] removeFromSuperview];

     UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    // Set button properties which you required here...
    //....

    [button setTag:[cell viewWithTag:kButtonTag + indexPath.row]];
    [button addTarget:self action:@selector(select:) forControlEvents:UIControlEventTouchDown];

    [cell.contentView addSubview:button];

在您的选择方法中，检查该按钮标签.

In your select method, check for that button tag.

- (void) select:(UIButton *)sender {
    NSInteger tag = sender.tag;
    NSInteger index = tag - kButtonTag;

    // Above index is unique index for your cell.
}

希望你能从这个简短的解释中得到想法.

Hope you will get idea, From this short explanation.

这篇关于滚动时表视图返回错误值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！