自定义的两端对齐的Label

#import <UIKit/UIKit.h>


@interface FNLabel : UIView
@property (nonatomic, strong)NSMutableAttributedString* string;
@property (nonatomic, strong)UIFont* font;
@property (nonatomic, strong)UIColor* textColor;

- (void)setText:(NSString*)text;
@end

  1 #import "FNLabel.h"
  2 #import <CoreText/CoreText.h>
  3 
  4 @implementation FNLabel
  5 
  6 - (id)initWithFrame:(CGRect)frame
  7 {
  8     self = [super initWithFrame:frame];
  9     if (self) {
 10         self.backgroundColor = [UIColor clearColor];
 11     }
 12     return self;
 13 }
 14 
 15 - (void)drawRect:(CGRect)rect
 16 {
 17     [self formatString];
 18     
 19     CGContextRef ctx = UIGraphicsGetCurrentContext();
 20     
 21     // 从文本空间到用户控件的转换矩阵
 22     CGContextSetTextMatrix(ctx, CGAffineTransformIdentity);
 23     // 缩放范围
 24     CGContextTranslateCTM(ctx,0, self.bounds.size.height);
 25     // 调整正确的坐标系
 26     CGContextScaleCTM(ctx, 1.0, -1.0);
 27     
 28     // 1.由富文本得到framesetter
 29     CTFramesetterRef frameSetter = CTFramesetterCreateWithAttributedString((__bridge CFAttributedStringRef)_string);
 30     // 2.由self.bounds得到path
 31     CGMutablePathRef path = CGPathCreateMutable();
 32     CGPathAddRect(path, NULL, self.bounds);
 33     // 3.由framesetter(内涵文本内容)，range(要画的范围)，path文本矩形 得到CTFrameRef
 34     CTFrameRef frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake(0, [_string length]), path, NULL);
 35     // 4.画文本
 36     CTFrameDraw(frame, ctx);
 37     
 38     CFRelease(path);
 39     CFRelease(frame);
 40     CFRelease(frameSetter);
 41 }
 42 #pragma mark - 普通的两端对齐文本
 43 - (void)setText:(NSString *)text
 44 {
 45     _string = [[NSMutableAttributedString alloc] initWithString:text];
 46     if (_textColor) {
 47         [_string addAttribute:NSForegroundColorAttributeName value:_textColor range:NSMakeRange(0, [_string length])];
 48     }
 49     if (_font) {
 50         [_string addAttribute:NSFontAttributeName value:_font range:NSMakeRange(0, [_string length])];
 51     }
 52     [self setNeedsDisplay];
 53 }
 54 #pragma mark - 保存整体文字颜色
 55 - (void)setTextColor:(UIColor *)textColor
 56 {
 57     _textColor = textColor;
 58 }
 59 #pragma mark - 保存整体字体
 60 - (void)setFont:(UIFont *)font
 61 {
 62     _font = font;
 63 }
 64 #pragma mark - 添加所有富文本属性
 65 - (void)setString:(NSMutableAttributedString *)string
 66 {
 67     
 68     NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:string.string];
 69     
 70     _string = str;
 71     // 设置文字颜色
 72     if (_textColor == nil) {
 73         _textColor = [UIColor blackColor];
 74     }
 75     [_string addAttribute:NSForegroundColorAttributeName value:_textColor range:NSMakeRange(0, [string length])];
 76     if (_font == nil) {
 77         _font = [UIFont systemFontOfSize:20];
 78     }
 79     // 设置文字字体
 80     [_string addAttribute:NSFontAttributeName value:_font range:NSMakeRange(0, [string length])];
 81     
 82     // 遍历添加所有字体文本属性
 83     [string enumerateAttribute:NSFontAttributeName inRange:NSMakeRange(0, _string.length) options:NSAttributedStringEnumerationLongestEffectiveRangeNotRequired usingBlock:^(id  _Nullable value, NSRange range, BOOL * _Nonnull stop) {
 84         if (value) {
 85             [_string addAttribute:NSFontAttributeName value:value range:range];
 86             
 87             [self setNeedsDisplay];
 88         }
 89     }];
 90     // 遍历添加所有颜色文本属性
 91     [string enumerateAttribute:NSForegroundColorAttributeName inRange:NSMakeRange(0, _string.length) options:NSAttributedStringEnumerationLongestEffectiveRangeNotRequired usingBlock:^(id  _Nullable value, NSRange range, BOOL * _Nonnull stop) {
 92         if (value) {
 93             [_string addAttribute:NSForegroundColorAttributeName value:value range:range];
 94             
 95             [self setNeedsDisplay];
 96         }
 97     }];
 98 }
 99 #pragma mark - 添加两端对齐属性
100 - (void)formatString
101 {
102     NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
103     style.alignment = NSTextAlignmentJustified;
104     style.lineSpacing = 5;
105     [_string addAttribute:NSParagraphStyleAttributeName value:style range:NSMakeRange(0, _string.length)];
106     
107 }
108 
109 @end