iOS5:如何在NSObject类中使用UIActionSheet对象并使其出现在另一个视图中？

Question

我有一个常见的方法,导致出现"联系我们"(UIActionSheet)消息.因为我在多个类中使用相同的代码,我试图移动到它自己的类(我使用NSObject类类型).

问题是,如何让UIActionSheet出现在需要它的类的NIB中？

我在NSObject类中使用此代码:

    UIActionSheet *msg = [[UIActionSheet alloc] 
                      initWithTitle:@"Consultation Request" 
                      delegate:self 
                      cancelButtonTitle:@"Cancel"  
                      destructiveButtonTitle:nil  
                      otherButtonTitles:@"Email",@"Text",@"Office Phone", nil];

msg.actionSheetStyle = UIActionSheetStyleBlackOpaque;

[msg showInView:self.view];

显然最后一行是错误的,因为"视图"是原始类的NIB.

Answer 1

有3个选项.

1.财产

您可以使用属性来告诉您NSObject应该在哪里显示您的操作表:

///// MyObject.h

@property (nonatomic, strong /* or rerain if not ARC */) UIView *viewForActionSheet;

//// MyObject.m

@synthesize viewForActionSheet;

...

[msg showInView:self.viewForActionSheet];


//// MyViewController.m

MyObject *obj = [[MyObject alloc] init];
obj.viewForActionSheet = self.view;
[obj presentMyActionSheet];

2.代表

这是使用obj-c协议(aka委托)的更高级方法

//// MyObject.h

@protocol MyObjectDelegate <NSObject>
@required

- (UIView *)viewForActionSheet;

@end;

@interface MyObject : NSObject

...

@property (nonatomic, unsafe_unretained /* or assign if not ARC */) id <MyObjectDelegate> delegate;

@end

//// MyObject.m

@synthesize delegate;

...

[msg showInView:self.delegate.viewForActionSheet];

//// MyViewController.m

- (UIView *)viewForActionSheet {
    return self.view;
}

3.窗口

最简单的方法,但不是最安全的方式

//// MyObject.m

[msg showInView:[[UIApplication sharedApplication] keyWindow]];