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继承是面向对象编程语言的三大特性之一，写好基类会给App的开发带来极大的方便。在iOS开发中，一般一个页面就对应一个ViewController，ViewController在开发中用的也很多，写一个好的ViewController的基类，会让开发变得轻松很多。
可以写一个BaseViewController，继承自UIViewController，在这里可以实现一些整个项目里ViewController的公共方法，最常用的就是导航栏相关的。一般App在设计的时候，导航栏的风格都比较同意，导航栏相关的方法可以放在基类里面实现，然后让其他的功能ViewController继承BaseViewController，这样导航栏部分就不用每个界面都处理了。 下面是我自己写的一个BaseViewController，具体的实现也要看App的主要功能，基类一般实现共性的功能，代码仅供参考，有更好建议的也欢迎评论留言交流。 BaseViewController.h代码：#import@interface BZBaseViewController : UIViewController//返回按钮@property(nonatomic,strong) UIButton * backButton;//导航栏标题@property(nonatomic,strong) UILabel * navigationTitleLabel;//导航栏右按钮（图片）@property(nonatomic,strong) UIButton * rightButton;//导航栏右按钮（文字）@property(nonatomic,strong) UIButton * rightTextButton;//为了灵活的满足不同的ViewController，将set方法放到.h文件，供子类调用-(void)setupNavigationItem;-(void)setBackButton;-(void)setRightButton;-(void)setNavigationTitleLabel;-(void)setRightTextButton;//返回按钮和右按钮点击方法，如果需要实现不同的方法，子类可以重新该方法-(void)navBackClick;-(void)navRightClick;-(void)navRightTextClick;@end
BaseViewController.m代码：
#import "BZBaseViewController.h"@interface BZBaseViewController ()@end@implementation BZBaseViewController- (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. //ViewController的背景颜色，如果整个App页面背景颜色比较统一，建议在这里设置 self.view.backgroundColor = COLOR_COMMON_LIGHTGRAY; //设置导航栏 [self setupNavigationItem]; self.navigationController.navigationBar.translucent = NO; self.navigationItem.hidesBackButton = YES; if (iOS11) { //scrollerView在导航栏透明时不下压 [[UIScrollView appearance] setContentInsetAdjustmentBehavior:UIScrollViewContentInsetAdjustmentNever]; }else{ self.automaticallyAdjustsScrollViewInsets = NO; }}-(void)setupNavigationItem{//导航栏背景 UIImage * image = [[UIImage imageNamed:@"img_navigationbar_bg"] resizableImageWithCapInsets:UIEdgeInsetsMake(-1, 0, 0, 0) resizingMode:UIImageResizingModeStretch]; [self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];}-(void)setBackButton{//设置返回按钮 UIBarButtonItem * backBarButton = [[UIBarButtonItem alloc] initWithCustomView:self.backButton]; self.navigationItem.leftBarButtonItem = backBarButton;}-(void)setRightButton{//设置右按钮（图片） UIBarButtonItem * rightBarButton = [[UIBarButtonItem alloc] initWithCustomView:self.rightButton]; self.navigationItem.rightBarButtonItem = rightBarButton;}-(void)setRightTextButton{//设置右按钮（文字） UIBarButtonItem * rightBarButton = [[UIBarButtonItem alloc] initWithCustomView:self.rightTextButton]; self.navigationItem.rightBarButtonItems = @[[self getNavigationSpacerWithSpacer:0],rightBarButton];}-(void)setNavigationTitleLabel{//设置标题 self.navigationItem.titleView = self.navigationTitleLabel;}-(UIBarButtonItem *)getNavigationSpacerWithSpacer:(CGFloat)spacer{//设置导航栏左右按钮的偏移距离 UIBarButtonItem *navgationButtonSpacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil]; navgationButtonSpacer.width = spacer; return navgationButtonSpacer;}#pragma mark - lazy 各控件的初始化方法-(UIButton *)backButton{ if (!_backButton) { _backButton = [UIButton buttonWithType:UIButtonTypeCustom]; _backButton.frame = CGRectMake(0, 0, 50, 40); [_backButton setImage:[UIImage imageNamed:@"button_nav_back"] forState:UIControlStateNormal]; _backButton.titleLabel.font = [UIFont systemFontOfSize:17]; [_backButton setContentEdgeInsets:UIEdgeInsetsMake(0, -40, 0, 0)]; [_backButton addTarget:self action:@selector(navBackClick) forControlEvents:UIControlEventTouchUpInside]; } return _backButton;}-(UIButton *)rightButton{ if (!_rightButton) { _rightButton = [UIButton buttonWithType:UIButtonTypeCustom]; _rightButton.frame = CGRectMake(0, 0, 40, 40); [_rightButton addTarget:self action:@selector(navRightClick) forControlEvents:UIControlEventTouchUpInside]; } return _rightButton;}-(UIButton *)rightTextButton{ if (!_rightTextButton) { _rightTextButton = [UIButton buttonWithType:UIButtonTypeCustom]; _rightTextButton.frame = CGRectMake(0, 0, 60, 40); _rightTextButton.titleLabel.font = [UIFont systemFontOfSize:17]; [_rightTextButton addTarget:self action:@selector(navRightTextClick) forControlEvents:UIControlEventTouchUpInside]; } return _rightTextButton;}-(UILabel *)navigationTitleLabel{ if (!_navigationTitleLabel) { _navigationTitleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH - 150, 30)]; _navigationTitleLabel.font = [UIFont systemFontOfSize:17]; _navigationTitleLabel.textColor = [UIColor whiteColor]; _navigationTitleLabel.textAlignment = NSTextAlignmentCenter; } return _navigationTitleLabel;}#pragma mark - click 导航栏按钮点击方法，右按钮点击方法都需要子类来实现-(void)navBackClick{ [self.navigationController popViewControllerAnimated:YES];}-(void)navRightClick{}-(void)navRightTextClick{}@end 写好基类之后，让其他页面继承于该基类，导航栏相关的设置直接调用这里面的方法即可，子类主要用来写自己的功能性代码就好，用起来也是很方便的。
当然如果要开发的App每个页面的导航栏差异比较大，UI风格也相差比较大的话可能就不太实用了，合适的才是最好的，需不需要基类、需要什么样的基类还是看具体项目。希望能给开发的小伙伴们带来帮助。转载地址：http://gdifb.baihongyu.com/