我正在尝试使用两个按钮为表格单元格附件视图制作一个视图，以便对该单元格索引处的对象执行两个（显然）不同的事情。我在 RootViewController（UITableView 所在的位置）中制作了两个带有选择器的基本圆角矩形 UIButton。这是我用来在 cellForRowAtIndexPath 方法中找到的单元格中初始化此视图的代码：
UIButton* minus = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain];
[minus setFrame:CGRectMake(0, 0, 30, 30)];
[minus setTitle:@"-" forState:UIControlStateNormal];
[minus addTarget:self action:@selector(subtractOne:event:) forControlEvents:UIControlEventTouchDown];
UIButton* plus = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain];
[plus setFrame:CGRectMake(30, 0, 30, 30)];
[plus setTitle:@"+" forState:UIControlStateNormal];
[plus addTarget:self action:@selector(addOne:event:) forControlEvents:UIControlEventTouchDown];
UIView* customAccessory = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 60, 30)];
[customAccessory addSubview:minus];
[customAccessory addSubview:plus];
cell.accessoryView = customAccessory;
[customAccessory release];
并且定义了他们调用的两种方法：
- (void)subtractOne:(id)sender forEvent:(UIEvent *)event;
- (void)addOne:(id)sender forEvent:(UIEvent *)event;
任何想法为什么这会将无法识别的发件人发送到实例“RootViewController”？
这是完整的错误：
2011-03-20 20:34:35.493 MyApp[23262:207]-[RootViewController minusOne:event:]：无法识别的选择器发送到实例 0x573c350 2011-03-20 20:34:35.496 MyApp[23262:207] *终止应用程序由于未捕获的异常“NSInvalidArgumentException”，原因：“-[RootViewController minusOne:event:]：无法识别的选择器发送到实例 0x573c350”