多个类写到一个类文件里面(高德官方demo源码总结)

iOS点滴

可以在一个类里面写多个 类 类的实现部分的顺序可以不一致

• 例子来自高德地图官方demo
  

  写的有点乱，解释下，就是在一个类文件里面 比如：

• .h文件中 声明两个类NaviButton和QuickStartAnnotationView

//
//  QuickStartAnnotationView.h
//  AMapNaviKit
//
//  Created by 刘博 on 16/3/9.
//  Copyright © 2016年 AutoNavi. All rights reserved.
//
#import <MAMapKit/MAMapKit.h>
@interface NaviButton : UIButton
@property (nonatomic, strong) UIImageView *carImageView;
@property (nonatomic, strong) UILabel *naviLabel;
@end
@interface QuickStartAnnotationView : MAPinAnnotationView
- (id)initWithAnnotation:(id <MAAnnotation>)annotation reuseIdentifier:(NSString *)reuseIdentifier;
@end

• .m中实现这两个类，而且实现的先后顺序随意

#import "QuickStartAnnotationView.h"
#define naviButtonWidth 44
#define naviButtonHeight 74
@implementation NaviButton
- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self)
    {
        [self setBackgroundImage:[UIImage imageNamed:@"naviBackgroundNormal"] forState:UIControlStateNormal];
        [self setBackgroundImage:[UIImage imageNamed:@"naviBackgroundHighlighted"] forState:UIControlStateSelected];
        //imageView
        _carImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"navi"]];
        [self addSubview:_carImageView];
        //label
        _naviLabel = [[UILabel alloc] init];
        _naviLabel.text = @"导航";
        _naviLabel.font = [_naviLabel.font fontWithSize:9];
        _naviLabel.textColor = [UIColor whiteColor];
        [_naviLabel sizeToFit];
        [self addSubview:_naviLabel];
    }
    return self;
}
#define kMarginRatio 0.1
- (void)layoutSubviews
{
    [super layoutSubviews];
    _carImageView.center = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.superview.frame) - CGRectGetHeight(_carImageView.frame) * (0.5 + kMarginRatio));
    _naviLabel.center = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.superview.frame) + CGRectGetHeight(_naviLabel.frame) * (0.5 + kMarginRatio));
}
@end
@implementation QuickStartAnnotationView
- (id)initWithAnnotation:(id <MAAnnotation>)annotation reuseIdentifier:(NSString *)reuseIdentifier
{
    self = [super initWithAnnotation:annotation reuseIdentifier:reuseIdentifier];
    if (self)
    {
        NaviButton *naviButton = [[NaviButton alloc] initWithFrame:(CGRectMake(0, 0, naviButtonWidth, naviButtonHeight))];
        self.leftCalloutAccessoryView = naviButton;
    }
    return self;
}
@end

再啰嗦几句，这个写法的好处，把多个不可分割的类写到一个文件里面
1.减少了文件数，便于查找
2.增强了耦合性，对于可以看成一个整体的部分，可以像这样当做一个整体来写！
3.代码简洁，逻辑清楚。