iOS开发实战之Label全方位对齐的轻松实现

#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

#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

- (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- (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; }