Question

我的UITableViewCell存在问题。我正在开发一个应用程序，其中一个Feed中的某些帖子可能包含一个图像，并且点击的按钮也需要包含一个“标签”编号，具体取决于该表的哪一行，因为我已经下载了一系列图像。

当我滚动（正如你已经猜到的）桌子时，问题出现了。图像加载很好，但是当我向上/向下滚动时，图像将会移到其他单元格上方，当单元格显示在屏幕上时，图像会快速将其位置更改为正确的位置等。

这是我的UITableView的代码：

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [feed count];
}

- (UITableViewCell *) getCellContentView:(NSString *)cellIdentifier 
{
    CGRect rect = [self.tableView bounds];
    CGRect CellFrame = CGRectMake(0.0f, 0.0f, rect.size.width, 10.0f);
    CGRect TitleFrame = CGRectMake(55.0f, 10.0f, 240.0f, 15.0f);
    CGRect TextFrame = CGRectMake(55.0f, 25.0f, 250.0f, 15.0f);
    CGRect PinFrame = CGRectMake(21.0f, 10.0f, 30.0f, 30.0f);
    CGRect ViewFrame = CGRectMake(50.0f, 35.0f, 260.0f, 0.0f);
    CGRect CommentsFrame = CGRectMake(300.0f, 10.0f, 20.0f, 15.0f);
    UILabel * lblTemp;

    UITableViewCell * cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
    [cell setFrame:CellFrame];

    lblTemp = [[UILabel alloc] initWithFrame:TitleFrame];
    lblTemp.tag = 1;
    lblTemp.numberOfLines = 0;
    lblTemp.opaque = NO;
    lblTemp.font = [UIFont systemFontOfSize:13.0f];
    lblTemp.backgroundColor = [UIColor clearColor];
    lblTemp.textColor = [UIColor blackColor];
    lblTemp.textAlignment = UITextAlignmentLeft;
    lblTemp.shadowColor = [UIColor whiteColor];
    lblTemp.shadowOffset = CGSizeMake(0, 1);
    [cell.contentView addSubview:lblTemp];

    lblTemp = [[UILabel alloc] initWithFrame:TextFrame];
    lblTemp.tag = 2;
    lblTemp.numberOfLines = 0;
    lblTemp.lineBreakMode = UILineBreakModeWordWrap;
    lblTemp.adjustsFontSizeToFitWidth = NO;
    lblTemp.font = [UIFont systemFontOfSize:13.0f];
    lblTemp.textColor = [UIColor lightGrayColor];
    lblTemp.backgroundColor = [UIColor clearColor];
    lblTemp.shadowColor = [UIColor whiteColor]; 
    lblTemp.shadowOffset = CGSizeMake(0, 1);
    [cell.contentView addSubview:lblTemp];

    lblTemp = [[UILabel alloc] initWithFrame:CommentsFrame];
    lblTemp.tag = 5;
    lblTemp.numberOfLines = 1;
    lblTemp.font = [UIFont systemFontOfSize:13.0f];
    lblTemp.textColor = [UIColor lightGrayColor];
    lblTemp.backgroundColor = [UIColor whiteColor];
    lblTemp.shadowColor = [UIColor whiteColor];
    lblTemp.shadowOffset = CGSizeMake(0, 1);
    [cell.contentView addSubview:lblTemp];

    UIImageView * imgTemp = [[UIImageView alloc] initWithFrame:PinFrame];
    imgTemp.tag = 3;
    [cell.contentView addSubview:imgTemp];

    UIView * viewTemp = [[UIView alloc] initWithFrame:ViewFrame];
    viewTemp.tag = 4;
    [viewTemp setBackgroundColor:[UIColor whiteColor]];
    [cell.contentView addSubview:viewTemp];

    return cell;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString * CellIdentifier = @"Cell";

    UITableViewCell * cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    //UITableViewCell * cell = [self getCellContentView:CellIdentifier];

    if (cell == nil) {
        cell = [self getCellContentView:CellIdentifier];
    } else {
        [cell.contentView viewWithTag:999];
    }

    cell.backgroundColor = [UIColor clearColor];

    UILabel * title         = (UILabel *)[cell viewWithTag:1];
    UILabel * journey       = (UILabel *)[cell viewWithTag:2];
    UIImageView * pin       = (UIImageView *) [cell viewWithTag:3];
    UILabel * comments      = (UILabel *)[cell viewWithTag:5];

    title.text = [NSString stringWithFormat:@"%@", [[feed objectAtIndex:indexPath.row] objectForKey:@"comment"]];
    [title sizeToFit];
    title.frame = CGRectMake(title.frame.origin.x, title.frame.origin.y, 240, title.frame.size.height);

    if ([[feed objectAtIndex:indexPath.row] objectForKey:@"weather_desc"] != [NSNull null] ||
        [[feed objectAtIndex:indexPath.row] objectForKey:@"weather_temp"] != [NSNull null]) {
            journey.text = [NSString stringWithFormat:@"It's %@ and %@°C.", [[feed objectAtIndex:indexPath.row] objectForKey:@"weather_desc"], [[feed objectAtIndex:indexPath.row] objectForKey:@"weather_temp"]];
    } else {
        journey.text = [NSString stringWithFormat:@"%@", [[[feed objectAtIndex:indexPath.row] objectForKey:@"journey"] objectForKey:@"name"]];
    }
    journey.frame = CGRectMake(journey.frame.origin.x, 10 + title.frame.size.height, 240, 15);

    if ([[feed objectAtIndex:indexPath.row] objectForKey:@"latitude"] != [NSNull null]) {
        pin.image = [UIImage imageNamed:@"LocationPin.png"];
    } else {
        pin.image = [UIImage imageNamed:@"Pin.png"];
    }

    if ([[feed objectAtIndex:indexPath.row] objectForKey:@"image_file_size"] != [NSNull null]) {
        NSString * text = [NSString stringWithFormat:@"%@", [[feed objectAtIndex:indexPath.row] objectForKey:@"comment"]];
        CGFloat height = [text sizeWithFont:[UIFont systemFontOfSize:13] constrainedToSize:CGSizeMake(250, 1500) lineBreakMode:UILineBreakModeWordWrap].height;

        UIImage * myImage = [images objectForKey:[NSString stringWithFormat:@"%i", indexPath.row]];

        UIButton * button = [[UIButton alloc] initWithFrame:CGRectZero];
        [button setBackgroundImage:myImage forState:UIControlStateNormal];
        [button setFrame:CGRectMake(title.frame.origin.x + 55.0f, 40.0f + height, 250.0f, myImage.size.height)];
        [button setTag:10 + indexPath.row];
        [button addTarget:self action:@selector(imagePressed:) forControlEvents:UIControlEventTouchUpInside];
        [cell addSubview:button];

        UIView * backView = (UIView *) [cell viewWithTag:4];
        [backView setFrame:CGRectMake(title.frame.origin.x + 50.0f, 35.0f + height, 260.0f, myImage.size.height + 10.0f)];
    } else {
        UIView * backView = (UIView *) [cell viewWithTag:4];
        [backView setFrame:CGRectZero];
        [backView setBackgroundColor:[UIColor clearColor]];
    }

    comments.text = [NSString stringWithFormat:@"%i", [[[feed objectAtIndex:indexPath.row] objectForKey:@"comments"] count]];

    UIImage * background = [UIImage imageNamed:@"CellBackground.png"];
    UIImageView *imageView = [[UIImageView alloc] initWithImage:background];
    imageView.contentMode = UIViewContentModeScaleToFill;
    [cell setBackgroundView:imageView];

    return cell;
}

- (void)tableView:(UITableView *)tv didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [self.tableView deselectRowAtIndexPath:indexPath animated:NO];
    MilestoneView * milestoneView = [[MilestoneView alloc] initWithNibName:@"MilestoneView" bundle:nil];
    [milestoneView setMilestone:[feed objectAtIndex:indexPath.row]];
    [self.navigationController pushViewController:milestoneView animated:YES];
}

- (CGFloat)tableView:(UITableView *)tv heightForRowAtIndexPath:(NSIndexPath *)indexPath 
{
    NSString * text = [NSString stringWithFormat:@"%@", [[feed objectAtIndex:indexPath.row] objectForKey:@"comment"]];
    CGFloat height = [text sizeWithFont:[UIFont systemFontOfSize:13] constrainedToSize:CGSizeMake(240, 1500) lineBreakMode:UILineBreakModeWordWrap].height;

    if ([[feed objectAtIndex:indexPath.row] objectForKey:@"image_file_size"] != [NSNull null]) {
        UIImage * myImage = [images objectForKey:[NSString stringWithFormat:@"%i", indexPath.row]];
        height += myImage.size.height + 15.0f;
    }

    return height + 37;
}

我也在使用Apple内置的'ARC'和iOS 5.0。

亲切的问候，

星

Answer 1

在此代码中，您在cellForRowAtIndexPath中添加按钮，因此会发生这种情况.... 所以，你在getCellContentView中添加了按钮，backView的代码，并从getCellContentView中的数组中获取图像。

UIImage *myImage = [images objectForKey:[NSString stringWithFormat:@"%i", indexPath.row]];

然后，

UIButton *button = [[UIButton alloc] initWithFrame:CGRectZero];
[button setBackgroundImage:myImage forState:UIControlStateNormal];
[button setFrame:CGRectMake(55.0f, 40.0f, 250.0f, myImage.size.height)];

改变高度，宽度和宽度x，y co-or。你想要什么和将单元格索引设置为按钮。

[button setTag:indexPath.row];
[button addTarget:self action:@selector(imagePressed:) forControlEvents:UIControlEventTouchUpInside];
[cell.contentView addSubview:button];

如果您有任何问题，请告诉我....

替换以下功能标题

- (UITableViewCell *) getCellContentView:(NSString *)cellIdentifier {
.
.
}

使用此功能

- (UITableViewCell *) getCellContentView:(NSString *)cellIdentifier  indexPathForButtonTag:(NSIndexPath*)indexPath {
.
.
}

替换cellForRowAtIndex

中的以下行

cell = [self getCellContentView:CellIdentifier];

使用

cell = [self getCellContentView:CellIdentifier indexPathForButtonTag:indexPath];

Answer 2

您不需要每个按钮都有不同的标签。您不应该在cellForRowAtIndexPath中向单元格添加任何子视图，因为您将不可避免地最终在子视图上添加子视图。我注意到您还在此方法中添加了一个图像视图作为单元格的背景 - 您只应在创建新单元格时执行此操作。

我将假设您没有使用xib文件进行此单元格布局，因此只需在contentView方法中添加该按钮并为其指定已知标记即可。

在按钮的操作方法中，您可以使用locationInView:和indexPathForRowAtPoint:方法找出按钮所在表格的哪一行：

CGPoint hit = [sender locationInView:self.tableView];
NSIndexPath *hitRow = [self.tableView indexPathForRowAtPoint:hit];

另外，请注意，将视图的.hidden属性设置为YES可能会减少将其框架设置为CGRectZero的工作量。

Answer 3

通过执行以下简单代码结束修复解决方案：

NSIndexPath *indexPath = [self.tableView indexPathForCell:(UITableViewCell *)[[sender superview]superview]];

我使用UIButton发件人来获取它所在的单元格。我还提取了.tag的所有修改并将它们保持在相同的数字。

在UITableViewCell中使用UIImages的UIButton - 重叠等

3 个答案: