使用 `UIActivityItemSource` 协议无法分享到 Instagram

Question

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

问题是，Instagram 仅在特定条件下在 UIActivityViewController 中可见。

总结以下测试：

• Instagram 仅在UIActivityViewController activityItems: [activityImage] 和 activityItems: [activityImage, NSNull()] 中可见

• Instagram 对于activityItems: [activityImage, activityText()]隐藏，即使返回的UIActivityItemSource 协议值为""、nil、NSNull()。

问题是需要调用UIActivityItemSource协议，这样不同的共享平台才能分开管理。

---

问题：

• 调用UIActivityItemSource协议时如何分享到Instagram？

• 在调用UIActivityItemSource 协议时，我可以尝试哪些""、nil 和NSNull() 的替代方案？

---

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 在UIActivityViewController中可见

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

或

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

Instagram 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

问题的提问和回答地址为：Share image with hashtag via UIActivityViewController (Twitter, Facebook, Instagram)

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

而实现字符串返回（或不返回）的类是：

@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

正如原始答案所指出的那样，关键是返回一个 NSObject（该类扩展了 NSObject）。然后在项目选择中，只需测试 instagram 以返回 nil，否则返回您的字符串。

Answer 2

测试后，您只需将图像添加到 activityViewControllerPlaceholderItem

final class MyImageItemSource: NSObject, UIActivityItemSource {

    final let image: UIImage

    init(image: UIImage) {
        self.image = image
    }

    func activityViewControllerPlaceholderItem(_ activityViewController: UIActivityViewController) -> Any {
        image
    }

    func activityViewController(_ activityViewController: UIActivityViewController, itemForActivityType activityType: UIActivity.ActivityType?) -> Any? {
        image
    }

}