前言
本文主要给大家介绍了关于iOS Label全方位对齐的实现方法，分享出来供大家参考学习，下面话不多说了，来一起看看详细的介绍吧
ARUILabelTextAlign
1. 实现 UILabel文本在 左(上 中 下)、中(上 中 下）、右(上 中 下) 9个方位显示；
2. 提供富文本底部不对齐的解决方案；
演示
核心代码：
ARAlignLabel.h
#import <UIKit/UIKit.h>@class ARMaker;typedef NS_ENUM(NSUInteger, textAlignType){ textAlignType_top = 10, // 顶部对齐 textAlignType_left, // 左边对齐 textAlignType_bottom, // 底部对齐 textAlignType_right, // 右边对齐 textAlignType_center // 水平/垂直对齐（默认中心对齐）};@interface ARAlignLabel : UILabel/** * 根据对齐方式进行文本对齐 * * @param alignType 对齐block */- (void)textAlign:(void(^)(ARMaker *make))alignType;@end//工具类@interface ARMaker : NSObject/* 存放对齐样式 */@property(nonatomic, strong) NSMutableArray *typeArray;/** * 添加对齐样式 */- (ARMaker *(^)(textAlignType type))addAlignType;@end
ARAlignLabel.m
#import "ARAlignLabel.h"@interface ARAlignLabel ()/* 对齐方式 */@property(nonatomic, strong) NSArray *typeArray;//上@property(nonatomic, assign) BOOL hasTop;//左@property(nonatomic, assign) BOOL hasLeft;//下@property(nonatomic, assign) BOOL hasBottom;//右@property(nonatomic, assign) BOOL hasRight;@end@implementation ARAlignLabel- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines { CGRect textRect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines]; if (self.typeArray){ for (int i=0; i<self.typeArray.count; i++) { textAlignType type = [self.typeArray[i] integerValue]; switch (type) { case textAlignType_top: //顶部对齐 self.hasTop = YES; textRect.origin.y = bounds.origin.y; break; case textAlignType_left: //左部对齐 self.hasLeft = YES; textRect.origin.x = bounds.origin.x; break; case textAlignType_bottom: //底部对齐 self.hasBottom = YES; textRect.origin.y = bounds.size.height - textRect.size.height; break; case textAlignType_right: //右部对齐 self.hasRight = YES; textRect.origin.x = bounds.size.width - textRect.size.width; break; case textAlignType_center: if (self.hasTop) { //上中 textRect.origin.x = (bounds.size.width - textRect.size.width)*0.5; } else if (self.hasLeft) { //左中 textRect.origin.y = (bounds.size.height - textRect.size.height)*0.5; } else if (self.hasBottom) { //下中 textRect.origin.x = (bounds.size.width - textRect.size.width)*0.5; } else if (self.hasRight) { //右中 textRect.origin.y = (bounds.size.height - textRect.size.height)*0.5; } else{ //上下左右居中 textRect.origin.x = (bounds.size.width - textRect.size.width)*0.5; textRect.origin.y = (bounds.size.height - textRect.size.height)*0.5; } break; default: break; } } } return textRect;}- (void)drawTextInRect:(CGRect)requestedRect { CGRect actualRect = requestedRect; if (self.typeArray) { actualRect = [self textRectForBounds:requestedRect limitedToNumberOfLines:self.numberOfLines]; } [super drawTextInRect:actualRect];}- (void)textAlign:(void(^)(ARMaker *make))alignType { ARMaker *make = [[ARMaker alloc]init]; alignType(make); self.typeArray = make.typeArray;}@end//工具类@implementation ARMaker- (instancetype)init { self = [super init]; if (self) { self.typeArray = [NSMutableArray array]; } return self;}- (ARMaker *(^)(enum textAlignType type))addAlignType { __weak typeof (self) weakSelf = self; return ^(enum textAlignType type) { [weakSelf.typeArray addObject:@(type)]; return weakSelf; };}@end
工具使用 - 九个方位对齐
- (void)viewDidLoad { [super viewDidLoad]; self.view.backgroundColor = [UIColor whiteColor]; if (_index == 9) { //富文本底部对齐 [self attributedTextAgainOfBottom]; }else { ARAlignLabel *label = [[ARAlignLabel alloc] initWithFrame:CGRectMake(kScreenWidth/2.0 - 150, 300, 300, 80)]; label.backgroundColor = [UIColor orangeColor]; label.textColor = [UIColor blackColor]; label.font = [UIFont systemFontOfSize:18]; label.text = @"爱学习，爱编程，爱咖啡可乐"; label.numberOfLines = 1; [self.view addSubview:label]; switch (_index) { case 0: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_left).addAlignType(textAlignType_top); }]; break; case 1: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_left).addAlignType(textAlignType_center); }]; break; case 2: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_left).addAlignType(textAlignType_bottom); }]; break; case 3: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_center).addAlignType(textAlignType_top); }]; break; case 4: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_center); }]; break; case 5: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_center).addAlignType(textAlignType_bottom); }]; break; case 6: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_right).addAlignType(textAlignType_top); }]; break; case 7: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_right).addAlignType(textAlignType_center); }]; break; case 8: [label textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_right).addAlignType(textAlignType_bottom); }]; break; default: break; } }}
富文本底部对齐
//富文本底部对齐- (void)attributedTextAgainOfBottom { CGFloat space = 10.0; ARAlignLabel *leftLB = [[ARAlignLabel alloc] initWithFrame:CGRectMake(20, 200, kScreenWidth/2.0 - 20 - space/2.0, 80)]; leftLB.backgroundColor = [UIColor lightGrayColor]; leftLB.textColor = [UIColor blackColor]; leftLB.numberOfLines = 1; [self.view addSubview:leftLB]; //右下 [leftLB textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_center); }]; NSMutableAttributedString *attributedArr = [[NSMutableAttributedString alloc] initWithString:@"单价 $123"]; [attributedArr setAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:40], NSForegroundColorAttributeName:[UIColor blackColor]} range:NSMakeRange(0, 1)]; [attributedArr setAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:25], NSForegroundColorAttributeName:[UIColor blackColor]} range:NSMakeRange(1, 1)]; [attributedArr setAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:20], NSForegroundColorAttributeName:[UIColor blueColor]} range:NSMakeRange(3, 1)]; [attributedArr setAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:35], NSForegroundColorAttributeName:[UIColor redColor]} range:NSMakeRange(4, attributedArr.length - 4)]; leftLB.attributedText = attributedArr; //对齐之后 ARAlignLabel *rightLB = [[ARAlignLabel alloc] initWithFrame:CGRectMake(kScreenWidth/2.0 + space/2.0, 200, leftLB.frame.size.width, 80)]; rightLB.backgroundColor = [UIColor lightGrayColor]; rightLB.textColor = [UIColor blackColor]; rightLB.numberOfLines = 1; [self.view addSubview:rightLB]; //左下 [rightLB textAlign:^(ARMaker *make) { make.addAlignType(textAlignType_center); }]; //设置部分文字的偏移量 (0是让文字保持原来的位置, 负值是让文字下移，正值是让文字上移) [attributedArr addAttribute:NSBaselineOffsetAttributeName value:@(1) range:NSMakeRange(0, 1)]; [attributedArr addAttribute:NSBaselineOffsetAttributeName value:@(0) range:NSMakeRange(1, 1)]; [attributedArr addAttribute:NSBaselineOffsetAttributeName value:@(-2) range:NSMakeRange(3, 1)]; [attributedArr addAttribute:NSBaselineOffsetAttributeName value:@(-3) range:NSMakeRange(4, attributedArr.length - 4)]; rightLB.attributedText = attributedArr;}
富文本底部对齐 - 使用场景：
Github：https://github.com/ArchLL/ARUILabelTextAlign（本地下载）
总结
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