self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"王儼" style:UIBarButtonItemStylePlain target:nil action:nil]; 

@interface ViewController ()  @end@implementation ViewController - (void)viewDidLoad {     [super viewDidLoad];    // 自定義返回按鈕     UIButton *button = [[UIButton alloc]initWithFrame:CGRectMake(0, 0, 44, 44)];     [button setTitle:@"王儼2" forState:UIControlStateNormal];     [button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];     [button addTarget:self action:@selector(back:) forControlEvents:UIControlEventTouchUpInside];    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:button]; } - (void)back:(UIButton *)button {     [self.navigationController popViewControllerAnimated:YES]; } - (void)viewWillAppear:(BOOL)animated {   [super viewWillAppear:animated];  if (self.navigationController.viewControllers.count > 1) {     // 記錄系統返回手勢的代理     _delegate = self.navigationController.interactivePopGestureRecognizer.delegate;     // 設置系統返回手勢的代理為當前控制器     self.navigationController.interactivePopGestureRecognizer.delegate = self;   } } - (void)viewWillDisappear:(BOOL)animated {   [super viewWillDisappear:animated];   // 設置系統返回手勢的代理為我們剛進入控制器的時候記錄的系統的返回手勢代理   self.navigationController.interactivePopGestureRecognizer.delegate = _delegate; }#pragma mark - UIGestureRecognizerDelegate- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {    return self.navigationController.childViewControllers.count > 1; } - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {  return self.navigationController.viewControllers.count > 1; }@end