前言
系统Api提供的textAlignment位置我们一般只会用到左边、右边、中间三种显示方式，于是写个分类提供更多的显示位置，分别包含左上、右上、左下、右下、中上、中下
采用Category的方式处理，简单方便使用
GitHub地址：KJEmitterView
简单介绍 Property & API
NS_ASSUME_NONNULL_BEGIN /// Label 文本显示样式 typedef NS_ENUM(NSUInteger, KJLabelTextAlignmentType) { KJLabelTextAlignmentTypeLeft = 0, KJLabelTextAlignmentTypeRight, KJLabelTextAlignmentTypeCenter, KJLabelTextAlignmentTypeLeftTop, KJLabelTextAlignmentTypeRightTop, KJLabelTextAlignmentTypeLeftBottom, KJLabelTextAlignmentTypeRightBottom, KJLabelTextAlignmentTypeTopCenter, KJLabelTextAlignmentTypeBottomCenter, }; @interface UILabel (KJExtension) /// 设置文字内容显示位置，外部不需要再去设置 " textAlignment " 属性 @property(nonatomic,assign)KJLabelTextAlignmentType kTextAlignmentType; /// 获取高度 - (CGFloat)kj_calculateHeightWithWidth:(CGFloat)width; /// 获取高度，指定行高 - (CGFloat)kj_calculateHeightWithWidth:(CGFloat)width OneLineHeight:(CGFloat)height; /// 获取文字尺寸 + (CGSize)kj_calculateLabelSizeWithTitle:(NSString*)title font:(UIFont*)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode; @end NS_ASSUME_NONNULL_END
1. kTextAlignmentType 设置文本位置，
这里需要注意的就是内部有使用到系统的textAlignment 属性，因此调用该属性的话，则不需要调用textAlignment属性
使用示例
CGFloat x,y; CGFloat sp = kAutoW(10); CGFloat w = (kScreenW-sp*4)/3.; CGFloat h = w*9/16; NSArray *names = @[@"左边",@"右边",@"中间",@"左上",@"右上",@"左下",@"右下",@"中上",@"中下"]; NSInteger types[9] = { KJLabelTextAlignmentTypeLeft, KJLabelTextAlignmentTypeRight, KJLabelTextAlignmentTypeCenter, KJLabelTextAlignmentTypeLeftTop, KJLabelTextAlignmentTypeRightTop, KJLabelTextAlignmentTypeLeftBottom, KJLabelTextAlignmentTypeRightBottom, KJLabelTextAlignmentTypeTopCenter, KJLabelTextAlignmentTypeBottomCenter }; for (int k=0; k<names.count; k++) { x = k%3*(w+sp)+sp; y = k/3*(h+sp)+sp+64+sp*2; UILabel *label = [UILabel kj_createLabelWithText:names[k] FontSize:16 TextColor:UIColor.orangeColor]; label.backgroundColor = [UIColor.orangeColor colorWithAlphaComponent:0.2]; label.kTextAlignmentType = types[k]; label.borderWidth = 1; label.borderColor = UIColor.orangeColor; label.frame = CGRectMake(x, y, w, h); [self.view addSubview:label]; }
Category
// // UILabel+KJExtension.m // KJEmitterView // // Created by 杨科军 on 2020/9/24. // Copyright © 2020 杨科军. All rights reserved. // https://github.com/yangKJ/KJExtensionHandler #import "UILabel+KJExtension.h" #import <objc/runtime.h> @implementation UILabel (KJExtension) - (KJLabelTextAlignmentType)kTextAlignmentType{ return (KJLabelTextAlignmentType)[objc_getAssociatedObject(self, @selector(kTextAlignmentType)) integerValue]; } - (void)setKTextAlignmentType:(KJLabelTextAlignmentType)kTextAlignmentType{ objc_setAssociatedObject(self, @selector(kTextAlignmentType), @(kTextAlignmentType), OBJC_ASSOCIATION_ASSIGN); static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ method_exchangeImplementations(class_getInstanceMethod(self.class, @selector(drawTextInRect:)), class_getInstanceMethod(self.class, @selector(kj_drawTextInRect:))); }); switch (kTextAlignmentType) { case KJLabelTextAlignmentTypeRight: case KJLabelTextAlignmentTypeRightTop: case KJLabelTextAlignmentTypeRightBottom: self.textAlignment = NSTextAlignmentRight; break; case KJLabelTextAlignmentTypeLeft: case KJLabelTextAlignmentTypeLeftTop: case KJLabelTextAlignmentTypeLeftBottom: self.textAlignment = NSTextAlignmentLeft; break; case KJLabelTextAlignmentTypeCenter: case KJLabelTextAlignmentTypeTopCenter: case KJLabelTextAlignmentTypeBottomCenter: self.textAlignment = NSTextAlignmentCenter; break; default: break; } } - (void)kj_drawTextInRect:(CGRect)rect{ switch (self.kTextAlignmentType) { case KJLabelTextAlignmentTypeRight: case KJLabelTextAlignmentTypeLeft: case KJLabelTextAlignmentTypeCenter: [self kj_drawTextInRect:rect]; break; case KJLabelTextAlignmentTypeBottomCenter: case KJLabelTextAlignmentTypeLeftBottom: case KJLabelTextAlignmentTypeRightBottom:{ CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines]; textRect.origin = CGPointMake(textRect.origin.x, -CGRectGetMaxY(textRect)+rect.size.height); [self kj_drawTextInRect:textRect]; } break; default:{ CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines]; [self kj_drawTextInRect:textRect]; } break; } } /// 获取高度 - (CGFloat)kj_calculateHeightWithWidth:(CGFloat)width{ self.numberOfLines = 0; self.lineBreakMode = NSLineBreakByCharWrapping; CGSize size = [UILabel kj_calculateLabelSizeWithTitle:self.text font:self.font constrainedToSize:CGSizeMake(width, MAXFLOAT) lineBreakMode:NSLineBreakByCharWrapping]; size.height += 3; return size.height; } /// 获取高度，指定行高 - (CGFloat)kj_calculateHeightWithWidth:(CGFloat)width OneLineHeight:(CGFloat)height{ self.numberOfLines = 0; self.lineBreakMode = NSLineBreakByCharWrapping; CGSize size = [UILabel kj_calculateLabelSizeWithTitle:self.text font:self.font constrainedToSize:CGSizeMake(width, MAXFLOAT) lineBreakMode:NSLineBreakByCharWrapping]; return size.height * height / self.font.lineHeight; } /// 获取文字尺寸 + (CGSize)kj_calculateLabelSizeWithTitle:(NSString*)title font:(UIFont*)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode{ if (title.length == 0) return CGSizeZero; NSMutableParagraphStyle *paragraph = [[NSMutableParagraphStyle alloc] init]; paragraph.lineBreakMode = lineBreakMode; CGRect frame = [title boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:font,NSParagraphStyleAttributeName:paragraph} context:nil]; return frame.size; } @end
