UILabel实现文字居上,居下,居中

应用场景,使用轻量级UILabel实现文字居上显示,或者居下显示的特殊UI要求下,使用频率不高(使用UITextview和UITextFiled也可以做,但是个人感觉不太合适)

代码如下:
LQLable.h

#import 

typedef NS_ENUM(NSUInteger, LQTextAlignment) {
    LQTextAlignmentTop,
    LQTextAlignmentMiddle,
    LQTextAlignmentBottom,
};

@interface LQLabel : UILabel

@property (nonatomic, assign) LQTextAlignment textAlignment;
@end

LQLable.m

#import "LQLabel.h"

@interface LQLabel ()

@end

@implementation LQLabel

@synthesize textAlignment = textAlignment_;

- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.textAlignment = LQTextAlignmentMiddle;
    }
    return self;
}

-(void)setTextAlignment:(LQTextAlignment)textAlignment {
    textAlignment_ = textAlignment;
    [self setNeedsDisplay];
}


- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {
    CGRect textRect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];
    switch (self.textAlignment) {
        case LQTextAlignmentTop:
            textRect.origin.y = bounds.origin.y;
            break;
        case LQTextAlignmentBottom:
            textRect.origin.y = bounds.origin.y + bounds.size.height - textRect.size.height;
            break;
        case LQTextAlignmentMiddle:
            
        default:
            textRect.origin.y = bounds.origin.y + (bounds.size.height - textRect.size.height) / 2.0;
    }
    return textRect;
}

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


@end

备注:如有不足请告知