我在ios 7下使用XCode 5来做一个简单的项目 . 当我按下以编程方式创建的按钮时出现以下错误:
2013-11-10 09:16:02.969 Project2[446:70b] +[KNSunDynamicUIButton buttonSavePressed:]: unrecognized selector sent to class 0x221424
细节:
我创建了一个自定义方法,用于以编程方式创建UIButton对象 . 该自定义方法用于任何视图控制器 . 该自定义方法需要传入的参数,如x,y,width,height,button title和selector,它们是一个事件处理程序,并像“ (SEL)selector ”一样传入 .
Custom method (属于助手类):
+(UIButton*)kNSunSetupWithSelector:(SEL)selector withX:(int)x y:(int)y width:(int)width height:(int)height
buttonTitle:(NSString*)buttonTitle backGroundColor:(CGColorRef) backGroundColor
{
UIButton* button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button setTitle:@"Save" forState:UIControlStateNormal];
button.frame = CGRectMake(x, y, width, height);
button.backgroundColor = [UIColor greenColor];
// selector is used over here
[button addTarget:self
action:selector
forControlEvents:UIControlEventTouchDown];
return button;
}
然后在 view controller .m file 中,我将该自定义方法称为:
-(void)setUpButtons
{
SEL selector = @selector(buttonSavePressed:);
_buttonSave = [KNSunDynamicUIButton kNSunSetupWithSelector:selector withX:470 y:410 width:160 height:40 buttonTitle:@"Save" backGroundColor:(_buttonSaveColor)];
[self.view addSubview:_buttonSave];
}
@interface MyViewController ()
{
...
// buttons
UIButton* _buttonSave;
}
@end
而 the same view controller .m file 中按钮的事件处理程序的定义如下:
- (void)buttonSavePressed:(UIButton*)button
{
NSLog(@"Button Save clicked.");
}
当我运行我的代码并点击按钮时,我看到如上所述的异常 . 请帮忙谢谢 .
附:如果我重写自定义方法作为其签名中没有"(SEL)selector"参数的替代方法,并且让调用该自定义方法的控制器视图完成编码选择器的工作,则会出现 no 异常:
-(void)setUpButtons
{
//Note: the codes are in my view controller .m file
_buttonSave = [KNSunDynamicUIButton kNSunSetupWithX:470 y:410 width:160 height:40 buttonTitle:@"Save" backGroundColor:_buttonSaveColor];
// Note: selector coding is taken care by codes of my view controller instead of by custom method
[_buttonSave addTarget:self
action:@selector(buttonSavePressed:)
forControlEvents:UIControlEventTouchDown];
[self.view addSubview:_buttonSave];
[_buttonSave setupView];
}
另一种自定义方法(我不喜欢这种方法,因为它没有处理动态传入选择器):
+(UIButton*)kNSunSetupWithX:(int)x y:(int)y width:(int)width height:(int)height
buttonTitle:(NSString*)buttonTitle backGroundColor:(CGColorRef) backGroundColor
{
UIButton* button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button setTitle:@"Save" forState:UIControlStateNormal];
button.frame = CGRectMake(x, y, width, height);
button.backgroundColor = [UIColor greenColor];
return button;
}
1 回答
问题在于辅助类:
在这里你说帮助器类将有方法're passing through selector, in you' re case
buttonSavePressed:
方法 .您应该在您的帮助方法中添加inController参数,以告知哪个控制器是放置的选择器方法 .
在您的特定情况下,辅助方法应该类似于此(请注意,在选择器参数之后添加了 inController 参数):
你应该通过这种方式从控制器中调用它: