使用'UIActivityItemSource`协议无法与Instagram共享

Question

我使用UIActivityViewController共享文本和图像。图片来自activityImage，这是一个UIImage()。自定义文本从activityText()这是从UIActivityItemSource协议返回。

问题在于，Instagram在某些条件下仅在UIActivityViewController中可见。

要summerize下面的测试：

• Instagram的是仅可见在UIActivityViewController为activityItems: [activityImage]和activityItems: [activityImage, NSNull()]

• Instagram的被隐藏为activityItems: [activityImage, activityText()]即使当返回UIActivityItemSource协议值是""，nil，NSNull()。

的问题是，UIActivityItemSource协议需要被调用，使不同的共享平台，可以单独管理。

---

问题：

• 我怎样才能调用UIActivityItemSource协议时分享的Instagram？

• 什么替代""，nil和NSNull()调用UIActivityItemSource协议时，我可以试试吗？

---

代码：

class activityText: NSObject, UIActivityItemSource { 
    @objc func activityViewControllerPlaceholderItem(activityViewController: UIActivityViewController) -> AnyObject { 
     return "" 
    } 
    @objc func activityViewController(activityViewController: UIActivityViewController, itemForActivityType activityType: String) -> AnyObject? { 
     switch activityType { 
     case UIActivityTypeMessage: 
      return "Special text when sharing to Messages." 
     default: 
      return "" 
     } 
    } 
} 

func shareEverwhere() { 
     var activityImage: UIImage() 
     let activity = UIActivityViewController(activityItems: [activityImage, activityText()], applicationActivities: nil) 
     self.presentViewController(activity, animated: true, completion: nil) 
} 

---

测试：

Instagram的是可见在UIActivityViewController

let activity = UIActivityViewController(activityItems: [activityImage], applicationActivities: nil) 

或

let activity = UIActivityViewController(activityItems: [activityImage, NSNull()], applicationActivities: nil) 

Instagram的被隐藏在UIActivityViewController

let activity = UIActivityViewController(activityItems: [activityImage, ""], applicationActivities: nil) 

或

let activity = UIActivityViewController(activityItems: [activityImage, activityText()], applicationActivities: nil) 

或

let activity = UIActivityViewController(activityItems: [activityImage, activityText()], applicationActivities: nil) 
class activityText: NSObject, UIActivityItemSource { 
    @objc func activityViewControllerPlaceholderItem(activityViewController: UIActivityViewController) -> AnyObject { 
     return "" 
    } 
    @objc func activityViewController(activityViewController: UIActivityViewController, itemForActivityType activityType: String) -> AnyObject? { 
     return NSNull() 
    } 
} 

或

let activity = UIActivityViewController(activityItems: [activityImage, activityText()], applicationActivities: nil) 
class activityText: NSObject, UIActivityItemSource { 
    @objc func activityViewControllerPlaceholderItem(activityViewController: UIActivityViewController) -> AnyObject { 
     return "" 
    } 
    @objc func activityViewController(activityViewController: UIActivityViewController, itemForActivityType activityType: String) -> AnyObject? { 
      return nil 
    } 
} 

或

let activity = UIActivityViewController(activityItems: [activityImage, activityText()], applicationActivities: nil) 
class activityText: NSObject, UIActivityItemSource { 
    @objc func activityViewControllerPlaceholderItem(activityViewController: UIActivityViewController) -> AnyObject { 
     return "" 
    } 
    @objc func activityViewController(activityViewController: UIActivityViewController, itemForActivityType activityType: String) -> AnyObject? { 
      return "" 
    } 
} 

Answer 1

有人问，在回答：Share image with hashtag via UIActivityViewController (Twitter, Facebook, Instagram)

 UIActivityViewController *activityViewController = 
[[UIActivityViewController alloc] initWithActivityItems:@[vm.image, [[ActivityStringItemSource alloc] initWithString:attributedString]] applicationActivities:nil]; 

和类实现字符串（或没有）的回报是：

@interface ActivityStringItemSource()<UIActivityItemSource> 

@property(strong, nonatomic) NSMutableAttributedString *stringContent; 
@end 

@implementation ActivityStringItemSource 

- (instancetype)initWithString:(NSMutableAttributedString *) placeholder 
{ 
    self = [super init]; 
    if (self) { 
     _stringContent = placeholder; 
    } 
    return self; 
} 

- (id)activityViewControllerPlaceholderItem:(UIActivityViewController *)activityViewController { 
    return [NSObject new]; 
} 

- (id)activityViewController:(UIActivityViewController *)activityViewController itemForActivityType:(UIActivityType)activityType { 
    if([activityType containsString:@"instagram"]) { 
     return nil; 
    } else { 
     return _stringContent; 
    } 
} 

@end 

的关键，如通过指向原来答案是返回一个NSObject（该类扩展NSObject的）。然后在项目选择中，只需测试instagram返回零，否则返回您的字符串。