表格单元格中的像素化UILabel

Question

要将 UILabel 添加到表格单元格，我使用

UILabel *timeLabel = [[UILabel alloc] initWithFrame:CGRectMake(270, 10, 40, 12)];
timeLabel.text = @"2s";
timeLabel.backgroundColor = [UIColor clearColor];
timeLabel.font = [UIFont systemFontOfSize:12];
timeLabel.textColor = [UIColor lightGrayColor];
timeLabel.highlightedTextColor = [UIColor whiteColor];
timeLabel.textAlignment = UITextAlignmentRight;
timeLabel.frame = CGRectIntegral(timeLabel.frame);
[cell.contentView addSubview:timeLabel]; 

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

。

这可以正常工作，直到我滚动表格或选择一个单元格。然后标签变得像素化。

加载时：

行动后

：

我还试图通过继承 UITableViewCell 来添加标签并加载它 - (void) layoutSubviews。

我已经找到相关问题here和here，但没有任何效果。

编辑：由于标准单元格标签已在使用中，因此无法使用标准单元格标签。我需要添加一个额外的标签。

Answer 1

我终于得到了一个肮脏的解决方案。

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

我设置

cell.selectionStyle = UITableViewCellSelectionStyleNone;。

在 UITableViewCell 的子类中，我在 initWithStyle 中加载timeLabel，如下所示：

timeLabel = [[UILabel alloc] initWithFrame:CGRectMake(270, 10, 40, 12)];
timeLabel.text = @"2s";
timeLabel.backgroundColor = [UIColor whiteColor];
timeLabel.font = [UIFont systemFontOfSize:12];
timeLabel.textColor = [UIColor lightGrayColor];
timeLabel.highlightedTextColor = [UIColor whiteColor];
timeLabel.textAlignment = UITextAlignmentRight;
[self.contentView addSubview:timeLabel];

然后我重写这两个函数：

#define UIColorFromRGB(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 green:((float)((rgbValue & 0xFF00) >> 8))/255.0 blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]

- (void)setHighlighted:(BOOL)highlighted animated:(BOOL)animated
{
    if(highlighted == YES){
        UIImage *image = [UIImage imageNamed:@"cellBg@2x.png"];
        //scale custom cell background to necessary height
        UIImage *scaledImage = [image scaleToSize:CGSizeMake(1,self.contentView.frame.size.height)];
        //set cell background
        self.backgroundColor = [UIColor colorWithPatternImage:scaledImage];
        //set textcolor for default labels
        self.textLabel.textColor = [UIColor whiteColor];
        self.detailTextLabel.textColor = [UIColor whiteColor];
        //set textcolor for custom label
        timeLabel.textColor = [UIColor whiteColor]; 
        //cope background for custom label background since timeLabel.backgroundColor = [UIColor clearColor] doesnt work
        CGImageRef ref = CGImageCreateWithImageInRect(scaledImage.CGImage, CGRectMake(0, 10, 12, 20));
        UIImage *img = [UIImage imageWithCGImage:ref];
        //set custom label background
        timeLabel.backgroundColor = [UIColor colorWithPatternImage:img];
    } else {
        //set unselected colors
        self.backgroundColor = [UIColor whiteColor];
        self.textLabel.textColor = [UIColor darkGrayColor];
        self.detailTextLabel.textColor = UIColorFromRGB(0x808080);
        timeLabel.textColor = UIColorFromRGB(0x808080);
        //white background works without the label pixelates
        timeLabel.backgroundColor = [UIColor whiteColor];
    }
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
    if(selected == YES){
        UIImage *image = [UIImage imageNamed:@"cellBg@2x.png"];
        UIImage *scaledImage = [image scaleToSize:CGSizeMake(1,self.contentView.frame.size.height)];
        self.backgroundColor = [UIColor colorWithPatternImage:scaledImage];
        self.textLabel.textColor = [UIColor whiteColor];
        self.detailTextLabel.textColor = [UIColor whiteColor];
        timeLabel.textColor = [UIColor whiteColor];
        CGImageRef ref = CGImageCreateWithImageInRect(scaledImage.CGImage, CGRectMake(0, 10, 12, 20));
        UIImage *img = [UIImage imageWithCGImage:ref];  
        timeLabel.backgroundColor = [UIColor colorWithPatternImage:img];
    } else {
        self.backgroundColor = [UIColor whiteColor];
        self.textLabel.textColor = [UIColor darkGrayColor];
        self.detailTextLabel.textColor = UIColorFromRGB(0x808080);
        timeLabel.textColor = UIColorFromRGB(0x808080);
        timeLabel.backgroundColor = [UIColor whiteColor];
    }
}

希望这可以帮助一些人！