ios - iOS 8 上的 UITableView 单元格宽度停留在 320pt

Question

我目前正在尝试在不使用 Storyboard的情况下使用自定义单元格创建一个简单的 UITableView。

我在 iPhone 6 模拟器上遇到一个问题，其中表格 View 的宽度为 375(应该如此)，但内部单元格的宽度为 320。

在项目中找不到数字 320，因为我没有对其进行硬编码。当我设置单元格的背景颜色时，它扩展了 375 的整个宽度，但我需要将图像向右对齐，它只对齐 320，如下图所示。

我不确定这是因为我缺少约束还是存在错误。感谢任何帮助，谢谢!

设置表格的代码:

- (TBMessageViewCell *)getMessageCellforTableView:(UITableView *)tableView atIndexPath:(NSIndexPath *)indexPath
{

    static NSString *cellIdentifier = @"MessageCell";
    TBMessageViewCell *cell = (TBMessageViewCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if (cell == nil) {
        cell = [[TBMessageViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
        [cell createSubviews];
    }

     // Set the new message and refresh
    [cell setMessage:self.viewModel.messages[indexPath.row]];
    [cell populateSubviews];
    cell.backgroundColor = [UIColor blueColor];

    NSLog(@"cell Width: %f", cell.contentView.frame.size.width);

    return cell;
}

完成 TBMessageViewCell:

@implementation TBMessageViewCell

const CGFloat MARGIN = 10.0f;
const CGFloat AVATAR_SIZE = 40.0f;

-(id)initWithStyle:(UITableViewCellStyle *)style reuseIdentifier:(NSString *)reuseIdentifier
{
    if(self = [super initWithStyle:UITableViewCellStyleDefault reuseIdentifier:reuseIdentifier]){
    }

// Sets background and selected background color
self.backgroundColor = [UIColor clearColor];
UIView *selectionColor = [[UIView alloc] init];
selectionColor.backgroundColor = [UIColor clearColor];
self.selectedBackgroundView = selectionColor;

return self;
}

- (void)populateSubviews
{
    // Set the message body
    [self.messageBodyLabel setText:self.message.body];
    [self.messageBodyLabel setTextAlignment:NSTextAlignmentRight];
    CGRect bodyFrame = CGRectMake(MARGIN, MARGIN, self.frame.size.width - (AVATAR_SIZE + (MARGIN * 3)), self.frame.size.height);
    // Calculates the expected frame size based on the font and dimensions of the label
    // FLT_MAX simply means no constraint in height
    CGSize maximumLabelSize = CGSizeMake(bodyFrame.size.width, FLT_MAX);
    CGRect textRect = [self.message.body boundingRectWithSize:maximumLabelSize
    options:NSStringDrawingUsesLineFragmentOrigin
    attributes:@{NSFontAttributeName:self.messageBodyLabel.font}
    context:nil];
    bodyFrame.size.height = textRect.size.height;

    // Setup the new avatar frame (Right aligned)
    CGRect avatarFrame = CGRectMake(bodyFrame.size.width + (MARGIN * 2), MARGIN, AVATAR_SIZE, AVATAR_SIZE);

    // Align to the LEFT side for current user's messages
    if ([[TBConfig userID] isEqualToString:self.message.user.userID]) {
        // Set avatar to left if it's me
        avatarFrame.origin.x = MARGIN;
        bodyFrame.origin.x = AVATAR_SIZE + (MARGIN * 2);
        [self.messageBodyLabel setTextAlignment:NSTextAlignmentLeft];
    }

    self.avatar.frame = avatarFrame;
    self.avatar.layer.cornerRadius = self.avatar.frame.size.width/2;
    self.messageBodyLabel.frame = bodyFrame;

    // Set the new cell height on the main Cell
    CGFloat cellHeight = MAX(bodyFrame.size.height, self.frame.size.height) + MARGIN;
    self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, cellHeight);

    // Set the new Profile avatar
    if (![self.avatar.profileID isEqualToString:self.message.user.facebookID]) {
        [self.avatar setProfileID:nil];
        [self.avatar setProfileID:self.message.user.facebookID];
    }
}

- (void)createSubviews
{
    self.messageBodyLabel = [[UILabel alloc] init];
    self.messageBodyLabel.textColor = [UIColor whiteColor];
    self.messageBodyLabel.lineBreakMode = NSLineBreakByWordWrapping;
    self.messageBodyLabel.numberOfLines = 0;
    [self addSubview:self.messageBodyLabel];

    // Creates the avatar
    self.avatar = [[FBProfilePictureView alloc] init];
    [self.avatar setPictureCropping:FBProfilePictureCroppingSquare];
    [self addSubview:self.avatar];
}

Answer 1

在将单元格添加到显示之前(在调整大小之前)，您正在打印单元格的大小。它还不知道它将被添加到的 tableview 的大小。

单元格在添加到显示时将被赋予适当的框架。

编辑:哦，您可能不希望cellIdentifier 是static。您可能需要 *const。