Question

我遇到了问题：我在我的UiNavigation控制器中以编程方式创建了一个UIBarButton。但是，我希望它在按下时会发出警报。但是，当我使用带有自定义文本的自定义栏按钮时，它不起作用：

self.navigationItem.rightBarButtonItem = self.editButtonItem;
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithTitle:@"Subscribe" style:UIBarButtonItemStyleDone target:nil action:@selector(subscribe:)];

self.navigationItem.rightBarButtonItem = addButton;

但是当我做一个普通的条形按钮时，它可以正常工作：

self.navigationItem.rightBarButtonItem = self.editButtonItem;
UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(subscribe:)];

self.navigationItem.rightBarButtonItem = addButton;

这是虚空：

-(void)subscribe:(id)sender {

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Highscore" message:@"" delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil, nil];

    [alert show];

}

提前致谢， Rafee

Answer 1

在初始化调用中将nil替换为target:

[[UIBarButtonItem alloc] initWithTitle:@"Subscribe" 
                                 style:UIBarButtonItemStyleDone 
                                target:nil  <---
                                action:@selector(subscribe:)];

self。您的alloc init应如下所示：

[[UIBarButtonItem alloc] initWithTitle:@"Subscribe" 
                                 style:UIBarButtonItemStyleDone 
                                target:self
                                action:@selector(subscribe:)];

发送给nil的消息不起作用; - ）

Answer 2

target必须是self，而不是nil。否则，没有人接受这个行动！

UIBarButton没有执行Action

2 个答案: