UITableView 滚动移除 UIButton 值

Posted 2023-03-04

【中文标题】UITableView 滚动移除 UIButton 值

【英文标题】：UITableView Scrolling removes the UIButton value

【发布时间】：2015-06-26 18:12:48

【问题描述】：

我有一个 UITableview 并添加了 UIButton 作为自定义视图。当我按下按钮时，它会更改所选按钮的标题，但当我滚动它时，它会恢复正常状态。请参阅下面的代码...

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
    // UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];

    static NSString *Cellidentifier = @"DataTableCellId";
    STCustomCell *cell = (STCustomCell *) [tableView dequeueReusableCellWithIdentifier:Cellidentifier];
    if (cell == nil) 

        NSArray *nib = [[NSBundle mainBundle]loadNibNamed:@"CellView" owner:self options:nil];
    cell = nib[0];

        cellButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        cellButton.tag=indexPath.row;
        [cellButton addTarget:self
                   action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchDown];
        [cellButton setTitle:@"Save" forState:UIControlStateNormal];
        cellButton.frame = CGRectMake(265.0, 20.0, 45.0, 27.0);
        cellButton.layer.borderColor = [UIColor lightGrayColor].CGColor;
        cellButton.tintColor = [UIColor lightGrayColor];
        cellButton.titleLabel.font = [UIFont systemFontOfSize:12.0];
        cellButton.layer.borderWidth = 1.0f;
        cellButton.layer.cornerRadius = 5;
        cellButton.layer.masksToBounds = YES;
        [cell.contentView addSubview:cellButton];

    

    return cell;


-(void)buttonClicked:(UIButton*)sender
      
        [sender setBackgroundColor:[UIColor lightGrayColor]];
        [sender setTintColor: [UIColor whiteColor]];
        [sender setTitle:@"Saved" forState:UIControlStateNormal];
        [sender addTarget:self
                   action:@selector(saveCell:) forControlEvents:UIControlEventTouchUpInside];
        sender.enabled = NO;

【参考方案1】：

首先，检查您的子句是否为 nil，检查您的单元格是否为 nil 并且不要实例化它是没有意义的。并且由于可重用行为，您的按钮会进入初始状态。所以，检查你的按钮的 enabled 属性

   
    NSMutableDictionary *buttonsState;


- (void)viewDidLoad 
    [super viewDidLoad];
    buttonsState = [NSMutableDictionary new];



- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
    // UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];

    static NSString *Cellidentifier = @"DataTableCellId";
    STCustomCell *cell = (STCustomCell *) [tableView dequeueReusableCellWithIdentifier:Cellidentifier];
    UIButton *cellButton = (UIButton*)[cell.contentView viewWithTag:indexPath.row];
    if (cell == nil) 

        cell = [[STCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:Cellidentifier]
    
    if (cellButton == nil)
    
        cellButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        cellButton.tag=indexPath.row;
        [cell.contentView addSubview:cellButton];

    

    if ([buttonsState objectForKey:@(indexPath.row)] == nil)
    
        [cellButton setTitle:@"Save" forState:UIControlStateNormal];
        cellButton.frame = CGRectMake(265.0, 20.0, 45.0, 27.0);
        cellButton.layer.borderColor = [UIColor lightGrayColor].CGColor;
        cellButton.tintColor = [UIColor lightGrayColor];
        cellButton.titleLabel.font = [UIFont systemFontOfSize:12.0];
        cellButton.layer.borderWidth = 1.0f;
        cellButton.layer.cornerRadius = 5;
        cellButton.layer.masksToBounds = YES;
        [cellButton addTarget:self
                       action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchDown];
    
    else
    
        [cellButton setBackgroundColor:[UIColor lightGrayColor]];
        [cellButton setTintColor: [UIColor whiteColor]];
        [cellButton setTitle:@"Saved" forState:UIControlStateNormal];
        [cellButton addTarget:self
                       action:@selector(saveCell:) forControlEvents:UIControlEventTouchUpInside];
    
    return cell;


-(void)buttonClicked:(UIButton*)sender

    [buttonsState setObject:@YES forKey:@(sender.tag)];

    [sender setBackgroundColor:[UIColor lightGrayColor]];
    [sender setTintColor: [UIColor whiteColor]];
    [sender setTitle:@"Saved" forState:UIControlStateNormal];
    [sender addTarget:self
               action:@selector(saveCell:) forControlEvents:UIControlEventTouchUpInside];
    sender.enabled = NO;

【讨论】：

感谢您的评论，但是当我添加 UIButton *cellButton = [cell.contentView viewForTag:indexPath.row];我得到一个“uiview”的不可见@interface 声明选择器 viewForTag 警告。

将 viewForTag 更改为 viewWithTag

它仍然给我一个不兼容的指针，并且这个方法不起作用

你是什么意思？你不能编译这个sn-p？我是从头开始写的，所以请告诉我到底哪里出了问题

更改 UIButton cellButton = [cell.contentView viewWithTag:indexPath.row];到 UIButton *cellButton =(UIButton) [cell.contentView viewWithTag:indexPath.row];