ios - UIButton 在单元格重新加载时创建两次

Question

我在 UITableViewCell 中有一个 UIButton。当应用程序首次启动时，它按预期工作，我在其中创建了它的框架。

当我滚动通过包含按钮的单元格时，它会在按钮下方创建第二个按钮实例。
这是一个视频来说明我的问题:http://pixori.al/DJ1k

这是 UITableViewCell 的代码以及我如何填充单元格。不确定为什么会这样。

#pragma mark - UITableViewDataSource

// 3 sections, (1 = mistarOverview) (2 = hourlyForecast) (3 = dailyForecast)
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 3;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    if (section == 0) {
        return MAX(6,6) + 1; //TODO add getNumberOfClasses for people with 7 or 8 classes
    } else if (section == 1) {
        return MIN([[MAManager sharedManager].hourlyForecast count], 6) + 1;
    } else {
        return MIN([[MAManager sharedManager].dailyForecast count], 6) + 1;
    }
}

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

    // Redefine layout variables in method from `viewDidLoad`
    CGFloat inset = 20; // For padding


    if (! cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier];
    }

    // Sets up attributes of each cell
    cell.selectionStyle = UITableViewCellSelectionStyleNone; //TODO none
    cell.backgroundColor = [UIColor colorWithWhite:0 alpha:0.2];
    cell.textLabel.textColor = [UIColor whiteColor];
    cell.detailTextLabel.textColor = [UIColor whiteColor];
    QBFlatButton* loginButton = nil;

    if (indexPath.section == 0) {
        if (indexPath.row == 0) {
            [self configureHeaderCell:cell title:@"Grades"];

            if ([cell.textLabel.text isEqual: @"Grades"] && (!loginButton) && (indexPath.row == 0) && (indexPath.section == 0)) {

                UIView *cellView = cell.contentView;
                CGRect loginButtonFrame = CGRectMake((cellView.frame.size.width - (80 + inset)), 18, 80, (cellView.frame.size.height));
                loginButton = [[QBFlatButton alloc] initWithFrame:loginButtonFrame];
                [loginButton addTarget:self action:@selector(loginButtonWasPressed)forControlEvents:UIControlEventTouchUpInside];
                loginButton.faceColor = [UIColor grayColor];
                loginButton.sideColor = [UIColor clearColor];

                loginButton.radius = 6.0;
                loginButton.margin = 4.0;
                loginButton.depth = 3.0;
                loginButton.alpha = 0.3;

                loginButton.titleLabel.font = [UIFont fontWithName:@"HelveticaNeue-Light" size:20];
                [loginButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
                [loginButton setTitle:@"Login" forState:UIControlStateNormal];
                [cellView addSubview:loginButton];
            }
        } else {
            cell.selectionStyle = UITableViewCellSelectionStyleBlue;
            cell.textLabel.text = [NSString stringWithFormat:@"Period %ld               A+", (long)indexPath.row];
            cell.detailTextLabel.text = @"Class name";
            //TODO get grades and config using method (TB Created)
        }
    } else if (indexPath.section == 1) {
        if (indexPath.row == 0) {
            [self configureHeaderCell:cell title:@"Hourly Forecast"];
        }
        else {
            // Get hourly weather and configure using method
            MACondition *weather = [MAManager sharedManager].hourlyForecast[indexPath.row - 1];
            [self configureHourlyCell:cell weather:weather];
        }
    }
    else if (indexPath.section == 2) {
        if (indexPath.row == 0) {
            [self configureHeaderCell:cell title:@"Daily Forecast"];
        }
        else if (indexPath.section == 2) {
            // Get daily weather and configure using method
            MACondition *weather = [MAManager sharedManager].dailyForecast[indexPath.row - 1];
            [self configureDailyCell:cell weather:weather];
        }
    }

    return cell;
}

Answer 1

实现以下 UITableView 委托(delegate)方法

-(void)tableView:(UITableView *)tableView didEndDisplayingCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
//In here, check the index path. When you have the cell that contains the button, pop it out from there by using [button removeFromSuperView];
}

当您将单元格出列时，您的问题就会出现。由于单元格被重复使用，它已经有了按钮，您只需再次重新添加它。这将解决您的问题。但是，我建议您为 UITableViewCell 创建一个子类，并在它的 prepareForReuse 方法中弹出按钮。由你决定。两者都可以。