How to set top-left alignment for UILabel for iOS application?

Solution 1:

It's fairly easy to do. Create a UILabel sublcass with a verticalAlignment property and override textRectForBounds:limitedToNumberOfLines to return the correct bounds for a top, middle or bottom vertical alignment. Here's the code:

SOLabel.h

#import <UIKit/UIKit.h>

typedef enum
{
    VerticalAlignmentTop = 0, // default
    VerticalAlignmentMiddle,
    VerticalAlignmentBottom,
} VerticalAlignment;

@interface SOLabel : UILabel

   @property (nonatomic, readwrite) VerticalAlignment verticalAlignment;

@end

SOLabel.m

@implementation SOLabel

-(id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (!self) return nil;

    // set inital value via IVAR so the setter isn't called
    _verticalAlignment = VerticalAlignmentTop;

    return self;
}

-(VerticalAlignment) verticalAlignment
{
    return _verticalAlignment;
}

-(void) setVerticalAlignment:(VerticalAlignment)value
{
    _verticalAlignment = value;
    [self setNeedsDisplay];
}

// align text block according to vertical alignment settings
-(CGRect)textRectForBounds:(CGRect)bounds 
    limitedToNumberOfLines:(NSInteger)numberOfLines
{
   CGRect rect = [super textRectForBounds:bounds 
                   limitedToNumberOfLines:numberOfLines];
    CGRect result;
    switch (_verticalAlignment)
    {
       case VerticalAlignmentTop:
          result = CGRectMake(bounds.origin.x, bounds.origin.y, 
                              rect.size.width, rect.size.height);
           break;

       case VerticalAlignmentMiddle:
          result = CGRectMake(bounds.origin.x, 
                    bounds.origin.y + (bounds.size.height - rect.size.height) / 2,
                    rect.size.width, rect.size.height);
          break;

       case VerticalAlignmentBottom:
          result = CGRectMake(bounds.origin.x, 
                    bounds.origin.y + (bounds.size.height - rect.size.height),
                    rect.size.width, rect.size.height);
          break;

       default:
          result = bounds;
          break;
    }
    return result;
}

-(void)drawTextInRect:(CGRect)rect
{
    CGRect r = [self textRectForBounds:rect 
                limitedToNumberOfLines:self.numberOfLines];
    [super drawTextInRect:r];
}

@end

Solution 2:

Rather than re-explaining, I will link to this rather extensive & highly rated question/answer:

Vertically align text to top within a UILabel

The short answer is no, Apple didn't make this easy, but it is possible by changing the frame size.

Solution 3:

I found a solution using AutoLayout in StoryBoard.

1) Set no of lines to 0 and text alignment to Left.

2) Set height constraint.

3) The height Constraint should be in Relation - Less Than or Equal

4)

   override func viewWillLayoutSubviews() {
        sampleLabel.sizeToFit()
    }

I got the result as follows :

Solution 4:

The SOLabel works for me.

Swift 3 & 5:

This version has been updated from the original to allow support for RTL languages:

public class VerticalAlignLabel: UILabel {
    enum VerticalAlignment {
        case top
        case middle
        case bottom
    }

    var verticalAlignment : VerticalAlignment = .top {
        didSet {
            setNeedsDisplay()
        }
    }

    override public func textRect(forBounds bounds: CGRect, limitedToNumberOfLines: Int) -> CGRect {
        let rect = super.textRect(forBounds: bounds, limitedToNumberOfLines: limitedToNumberOfLines)

        if UIView.userInterfaceLayoutDirection(for: .unspecified) == .rightToLeft {
            switch verticalAlignment {
            case .top:
                return CGRect(x: self.bounds.size.width - rect.size.width, y: bounds.origin.y, width: rect.size.width, height: rect.size.height)
            case .middle:
                return CGRect(x: self.bounds.size.width - rect.size.width, y: bounds.origin.y + (bounds.size.height - rect.size.height) / 2, width: rect.size.width, height: rect.size.height)
            case .bottom:
                return CGRect(x: self.bounds.size.width - rect.size.width, y: bounds.origin.y + (bounds.size.height - rect.size.height), width: rect.size.width, height: rect.size.height)
            }
        } else {
            switch verticalAlignment {
            case .top:
                return CGRect(x: bounds.origin.x, y: bounds.origin.y, width: rect.size.width, height: rect.size.height)
            case .middle:
                return CGRect(x: bounds.origin.x, y: bounds.origin.y + (bounds.size.height - rect.size.height) / 2, width: rect.size.width, height: rect.size.height)
            case .bottom:
                return CGRect(x: bounds.origin.x, y: bounds.origin.y + (bounds.size.height - rect.size.height), width: rect.size.width, height: rect.size.height)
            }
        }
    }

    override public func drawText(in rect: CGRect) {
        let r = self.textRect(forBounds: rect, limitedToNumberOfLines: self.numberOfLines)
        super.drawText(in: r)
    }
}

Swift 1:

class UIVerticalAlignLabel: UILabel {

enum VerticalAlignment : Int {
    case VerticalAlignmentTop = 0
    case VerticalAlignmentMiddle = 1
    case VerticalAlignmentBottom = 2
}

var verticalAlignment : VerticalAlignment = .VerticalAlignmentTop {
    didSet {
        setNeedsDisplay()
    }
}

required init(coder aDecoder: NSCoder){
    super.init(coder: aDecoder)
}

override func textRectForBounds(bounds: CGRect, limitedToNumberOfLines: Int) -> CGRect {
    let rect = super.textRectForBounds(bounds, limitedToNumberOfLines: limitedToNumberOfLines)

    switch(verticalAlignment) {
        case .VerticalAlignmentTop:
            return CGRectMake(bounds.origin.x, bounds.origin.y, rect.size.width, rect.size.height)
        case .VerticalAlignmentMiddle:
            return CGRectMake(bounds.origin.x, bounds.origin.y + (bounds.size.height - rect.size.height) / 2, rect.size.width, rect.size.height)
        case .VerticalAlignmentBottom:
            return CGRectMake(bounds.origin.x, bounds.origin.y + (bounds.size.height - rect.size.height), rect.size.width, rect.size.height)
        default:
            return bounds
    }
}

override func drawTextInRect(rect: CGRect) {
    let r = self.textRectForBounds(rect, limitedToNumberOfLines: self.numberOfLines)
    super.drawTextInRect(r)
    }
}