IOS 7中的表格视图单元格扩展

Posted 2023-03-03

【中文标题】IOS 7中的表格视图单元格扩展

【英文标题】：Table view cell expanding in IOS 7

【发布时间】：2013-10-01 09:08:04

【问题描述】：

我正在开发一个 ios 应用程序。我使用了表格视图。当用户单击任何单元格时，该单元格就会展开。但有些单元格在 iOS 7 中没有扩展。其他版本运行正常。下面是示例代码。我该如何纠正？

- (BOOL)cellIsSelected:(NSIndexPath *)indexPath 
    // Return whether the cell at the specified index path is selected or not
    NSNumber *selectedIndex = [selectedIndexes objectForKey:indexPath];
    return selectedIndex == nil ? FALSE : [selectedIndex boolValue];



#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView

    return 1;


- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

    if([self cellIsSelected:indexPath])
        
            return 111;
        
        // Cell isn't selected so return single height
        return 41;


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

    return  [self.filteredItineraries count];


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

    static NSString *simpleTableIdentifier = @"FlightTracker";

    CellFlightTracker *cell = (CellFlightTracker *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];


    if(cell == nil)
    
        NSArray *nib=nil;

        nib = [[NSBundle mainBundle] loadNibNamed:@"CellFlightTracker" owner:self options:nil];

        cell = [nib objectAtIndex:0];
     




        if([self cellIsSelected:indexPath])
        
            cell.backgroundColor=[UIColor blackColor];
        else
        
            cell.backgroundColor=[UIColor darkGrayColor];
        


    return cell;


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

     if([self cellIsSelected:indexPath])
             cell.backgroundColor= [UIColor blackColor];
         else
             cell.backgroundColor= [UIColor darkGrayColor];


-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath

    [tableView deselectRowAtIndexPath:indexPath animated:TRUE];

        // Toggle 'selected' state
        BOOL isSelected = ![self cellIsSelected:indexPath];

        // Store cell 'selected' state keyed on indexPath
        NSNumber *selectedIndex = [NSNumber numberWithBool:isSelected];
        [selectedIndexes setObject:selectedIndex forKey:indexPath];


        // This is where magic happens...
        [tableView1 beginUpdates];
        CellFlightTracker *selectedCell = (CellFlightTracker*)[tableView cellForRowAtIndexPath:indexPath];



        if(selectedCell.lblDepartureAirportStatus.hidden)
            [selectedCell.lblDepartureAirportStatus setHidden:NO];
        else
            [selectedCell.lblDepartureAirportStatus setHidden:YES];


        [tableView1 endUpdates];

【问题讨论】：

看看 cellIsSelected 的实现会很有用：...

作为一个测试，你能把[tableView deselectRowAtIndexPath:indexPath animated:TRUE]注释掉或者换成[tableView deselectRowAtIndexPath:indexPath animated:NO]吗？我在表格视图单元格中遇到了堆叠动画的问题。

@JefferyThomas 我试过但没用：/

【参考方案1】：

如果你把UITableViewCell子类化并在调整单元格大小时使用layoutSubviews来调整会更好。

//In SMTableViewCell.h

@interface SMTableViewCell : UITableViewCell

@property (weak, nonatomic) IBOutlet UILabel *statusLabel;
@property (weak, nonatomic) IBOutlet UIButton *seeMoreButton;

//SMTableViewCell.m

- (void)layoutSubviews

    CGRect labelFrame = self.statusLabel.frame;
    labelFrame.size.height = self.frame.size.height - 55.0f;
    self.statusLabel.frame = labelFrame;

    CGRect buttonFrame = self.seeMoreButton.frame;
    buttonFrame.origin.y = labelFrame.origin.y+labelFrame.size.height+10.0f;
    self.seeMoreButton.frame = buttonFrame;

保留一个数组来存储 selectedIndexPaths

@property (nonatomic, strong) NSMutableArray *selectedIndexPaths;

计算单元格的高度

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;

    BOOL isSelected = [self.selectedIndexPaths containsObject:indexPath];

    CGFloat maxHeight = MAXFLOAT;
    CGFloat minHeight = 40.0f;

    CGFloat constrainHeight = isSelected?maxHeight:minHeight;
    CGFloat constrainWidth  = tableView.frame.size.width - 20.0f;

    NSString *text       = self.items[indexPath.row];
    CGSize constrainSize = CGSizeMake(constrainWidth, constrainHeight);
    CGSize labelSize     = [text sizeWithFont:[UIFont systemFontOfSize:15.0f]
                            constrainedToSize:constrainSize
                                lineBreakMode:NSLineBreakByCharWrapping];

    return MAX(labelSize.height+75, 100.0f);

初始化自定义显示更多TableViewCell

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

    static NSString *cellIdentifier = @"CellIdentifier";

    SMTableViewCell *cell= (SMTableViewCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];

    if (cell == nil)
    
        cell = [[[NSBundle mainBundle]loadNibNamed:NSStringFromClass([SMTableViewCell class])
                                             owner:nil
                                           options:nil] lastObject];
    

    BOOL isSelected = [self.selectedIndexPaths containsObject:indexPath];
    cell.statusLabel.numberOfLines = isSelected?0:2;

    NSString *text = self.items[indexPath.row];
    cell.statusLabel.text = text;


    NSString *buttonTitle = isSelected?@"See Less":@"See More";
    [cell.seeMoreButton setTitle:buttonTitle forState:UIControlStateNormal];
    [cell.seeMoreButton addTarget:self action:@selector(seeMoreButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
    [cell.seeMoreButton setTag:indexPath.row];

    cell.selectionStyle = UITableViewCellSelectionStyleNone;

    return cell;

按钮点击事件方法

- (void)seeMoreButtonPressed:(UIButton *)button

    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:button.tag inSection:0];
    [self addOrRemoveSelectedIndexPath:indexPath];


- (void)addOrRemoveSelectedIndexPath:(NSIndexPath *)indexPath

    if (!self.selectedIndexPaths) 
        self.selectedIndexPaths = [NSMutableArray new];
    

    BOOL containsIndexPath = [self.selectedIndexPaths containsObject:indexPath];

    if (containsIndexPath) 
        [self.selectedIndexPaths removeObject:indexPath];
    else
        [self.selectedIndexPaths addObject:indexPath];
    

    [self.tableView reloadRowsAtIndexPaths:@[indexPath]
                     withRowAnimation:UITableViewRowAnimationFade];

如果单元格被选中，则会给出相同的事件

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath

    [tableView deselectRowAtIndexPath:indexPath animated:YES];

    [self addOrRemoveSelectedIndexPath:indexPath];

样本Demo project link.

【讨论】：

谢谢@Vivek，您的代码正在运行。但我不明白我能做什么：/

修复 iOS 8 中的分隔符，SMTableViewCell.m 中的call super in layoutSubviews