给初学者写的tapGesture和返回按钮写法的示例

给菜鸟写的tapGesture和返回按钮写法的示例
菜鸟真的很菜，还不爱学习，不怕神一样的对手，只怕不爱学习的菜鸟。

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    UIImage *returnBtnImage = [UIImage imageNamed:@"return_btn.png"];
    [btn setFrame:CGRectMake(0, 0, returnBtnImage.size.width, returnBtnImage.size.height)];
    [btn setBackgroundImage:returnBtnImage forState:UIControlStateNormal];
    [btn setTitle:@"  返回" forState:UIControlStateNormal];
    [btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [btn.titleLabel setFont:[UIFont boldSystemFontOfSize:12]];
    [btn addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
    
    UIBarButtonItem *backBtn = [[UIBarButtonItem alloc]initWithCustomView:btn];
    self.navigationItem.leftBarButtonItem = backBtn;
    
    UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 30, 30)];
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapCheck:)];
    tap.numberOfTapsRequired = 1;
    [imageView addGestureRecognizer:tap];
}