在c#中，这在UITableViewCell中为我工作。

        UILabel myLabel = new UILabel();
        myLabel.Font = UIFont.SystemFontOfSize(16);
        myLabel.Lines = 0;
        myLabel.TextAlignment = UITextAlignment.Left;
        myLabel.LineBreakMode = UILineBreakMode.WordWrap;
        myLabel.MinimumScaleFactor = 1;
        myLabel.AdjustsFontSizeToFitWidth = true;

       myLabel.InvalidateIntrinsicContentSize();
       myLabel.Frame = new CoreGraphics.CGRect(20, mycell.ContentView.Frame.Y + 20, cell.ContentView.Frame.Size.Width - 40, mycell.ContentView.Frame.Size.Height);
       myCell.ContentView.AddSubview(myLabel);

我认为这里的重点是:-

            myLabel.TextAlignment = UITextAlignment.Left;
            myLabel.LineBreakMode = UILineBreakMode.WordWrap;
            myLabel.MinimumScaleFactor = 1;
            myLabel.AdjustsFontSizeToFitWidth = true;

当使用NSString填充UILabel时，您可以使用\r转到下一行。

UILabel * label;


label.text = [NSString stringWithFormat:@"%@ \r %@",@"first line",@"seconcd line"];

你应该试试这个:

-(CGFloat)dynamicLblHeight:(UILabel *)lbl
{
    CGFloat lblWidth = lbl.frame.size.width;
    CGRect lblTextSize = [lbl.text boundingRectWithSize:CGSizeMake(lblWidth, MAXFLOAT)
                                               options:NSStringDrawingUsesLineFragmentOrigin
                                            attributes:@{NSFontAttributeName:lbl.font}
                                               context:nil];
    return lblTextSize.size.height;
}

已经回答了，但你也可以在故事板中手动执行。在标签的属性检查器下，可以将换行符更改为换行(或字符换行)。

UILabel *textLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 150, 30)];
[textLabel sizeToFit];
textLabel.numberOfLines = 0;
textLabel.text = @"Your String...";

斯威夫特4:

label.lineBreakMode = .byWordWrapping

label.numberOfLines = 0

label.translatesAutoresizingMaskIntoConstraints = false

label.preferredMaxLayoutWidth = superview.bounds.size.width - 10