导航栏按钮未显示

Question

当试图在左侧和右侧添加导航按钮时,它没有显示？这是我用过的代码,这有什么不对吗？

这是我在appdelegate中添加导航栏的方式,

  UIViewController *viewController1 = [[logyFirstViewController alloc] initWithNibName:@"logyFirstViewController" bundle:nil];
  UIViewController *viewController2 = [[logySecondViewController alloc] initWithNibName:@"logySecondViewController" bundle:nil];
  UIViewController *viewController3 = [[record alloc] initWithNibName:@"record" bundle:nil];
  UIViewController *viewController4 = [[searchview alloc] initWithNibName:@"searchview" bundle:nil];
  UIViewController *viewController5 = [[profilde alloc] initWithNibName:@"profilde" bundle:nil];
 self.tabBarController = [[UITabBarController alloc] init];

self.tabBarController.viewControllers = @[viewController1, viewController2, viewController3, viewController4, viewController5];
navigationController = [[UINavigationController alloc] initWithRootViewController:self.tabBarController];

self.navigationController.navigationBar.barStyle=UIBarStyleDefault;

[navigationController.navigationBar setAlpha:0.8f];
 [self.window addSubview:[navigationController view]];





 button4 = [UIButton buttonWithType:UIButtonTypeCustom];
 [button4 setFrame:CGRectMake(0.0f, 0.0f, 25.0f, 25.0f)];
 [button4 addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
 [button4 setImage:[UIImage imageNamed:@"del.png"] forState:UIControlStateNormal];
 UIBarButtonItem *random1 = [[UIBarButtonItem alloc] initWithCustomView:button4];
 self.navigationController.navigationItem.leftBarButtonItem=random1;

请帮忙.

Answer 1

我看到您的代码没有问题,只需检查您的图像或尝试使用圆角矩形图像进行测试

UIButton* button4 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button4 setFrame:CGRectMake(0.0f, 0.0f, 25.0f, 25.0f)];
[button4 addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *random1 = [[UIBarButtonItem alloc] initWithCustomView:button4];

并使用 self.navigationController.navigationBar.topItem.leftBarButtonItem=random1; 而不是 self.navigationController.navigationItem.leftBarButtonItem=random1;