Question

我试图弄清楚这一段时间了：

我在tableview中有一个自定义单元格，它有两个标签，一个在另一个之下。顶部标签最多可以是一行或两行。底部标签仅限于一行。

顶部标签将始终存在，但底部标签将存在于某些单元格中，而我的其他单元格则不存在。

我需要一种方法来弄清楚如何将这些标签垂直居中。我尝试使用cell.label1.numberOfLines = 0;使顶级标签动态化但是标签1实际上并不限于2行。

我尝试通过计算第一个标签的高度然后将两个标签排列在中心来垂直居中这些标签。

如果我使用xib将行数限制为2，则第一个标签的高度始终计算为2行，即使标签消耗1行也是如此。我看到的一个问题是，如果我使用[cell.label1 sizeToFit];，那么在滚动表格时，标签似乎总是会改变显示的文本。显示的文本总是针对相应的标签，但文本有时会在中途包装，有时会使用整行。

以下是我的参考代码：

CustomCell1 *cell = (CustomCell1 *)[self.tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil)
{
    NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"CustomCell1" owner:self options:nil];
    cell = [nib objectAtIndex:0];
    cell.label1.lineBreakMode = UILineBreakModeWordWrap;
    cell.label1.numberOfLines = 0;
    cell.label1.tag = [indexPath row];
}
cell.label1.text = [[responseArray objectAtIndex:[indexPath row]] text];
if([[[responseArray objectAtIndex:[indexPath row]] isDone] isEqualToString:@"N"]) {
    cell.label2.text = @"";
} else {
    cell.label2.text = @"Done";
}

//[cell.label1 sizeToFit];

CGSize label1Size = [cell.label1 frame].size;
CGFloat label1Height = label1Size.height;
CGRect label1Frame = cell.label1.frame;
int numLines = (int)(label1Height/cell.label1.font.leading);

CGSize label2Size = [cell.label2 frame].size;
CGFloat label2Height = label2Size.height;
CGRect label2Frame = cell.label2.frame;

if(numLines > 1) {

    if([cell.label2.text isEqualToString:@""]) {
        //if label2 == "" then center label1
        label1Frame.origin.y = cellHeight/2 - label1Height/2;
        cell.label1.frame = label1Frame;
    } else {
        label1Frame.origin.y = 12;
        cell.label1.frame = label1Frame;
        label2Frame.origin.y = 52; 
        cell.label2.frame = label2Frame;
    }
} else {
    if([cell.label2.text isEqualToString:@""]) {
        CGRect frame = cell.label1.frame;
        frame.origin.y = cellHeight/2 - label1Height/2;
        cell.label1.frame = frame;
    } else {
        label1Frame.origin.y = cellHeight/2 - label1Height/2;
        cell.label1.frame = label1Frame;
        label2Frame.origin.y = cellHeight/2;
        cell.label2.frame = label2Frame;
    }
}

请帮助我IOS大师提出你的建议。

Answer 1

最好将调整大小计算移动到layoutSubviews。

//CustomCell.m

- (void)layoutSubviews{

CGRect label1Frame = self.label1.frame;
//Calculate the size of label 1
CGSize label1Size = [self.label1.text sizeWithFont:[self.label1 font]
                                constrainedToSize:CGSizeMake(label1Frame.size.width,42.0f)
                                    lineBreakMode:NSLineBreakByTruncatingTail];
label1Frame.size.height = label1Size.height;

CGRect label2Frame = self.label2.frame;
//Calculate the size of label 2
CGSize label2Size = [self.label2.text sizeWithFont:[self.label2 font]
                                 constrainedToSize:CGSizeMake(label2Frame.size.width,21.0f)
                                     lineBreakMode:NSLineBreakByTruncatingTail];
label2Frame.size.height = label2Size.height;

//Total height of labels
CGFloat totalHeight = label1Frame.size.height+label2Frame.size.height+5.0f;

//For centering half of difference of two labels with cell
label1Frame.origin.y = (self.frame.size.height - totalHeight)/2.0f;
self.label1.frame = CGRectIntegral(label1Frame);

label2Frame.origin.y = label1Frame.origin.y+label1Frame.size.height+5.0f;
self.label2.frame = CGRectIntegral(label2Frame);

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
     CustomCell1 *cell = (CustomCell1 *)[self.tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
     if (cell == nil)
     {
         NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"CustomCell1" owner:self options:nil];
        cell = [nib objectAtIndex:0];
        cell.label1.lineBreakMode = UILineBreakModeWordWrap;
        cell.label1.numberOfLines = 2;
        cell.label1.tag = [indexPath row];
    }
    cell.label1.text = [[responseArray objectAtIndex:[indexPath row]] text];
    if([[[responseArray objectAtIndex:[indexPath row]] isDone] isEqualToString:@"N"]) {
        cell.label2.text = @"";
    } else {
        cell.label2.text = @"Done";
    }

    return cell;

}

具有动态标签高度的IOS Uitableview自定义单元格

1 个答案: