具体功能百度去吧
1、UIActivityViewController
2、SLComposeViewController 这个，好像加了文字和标题，图片就只能转发一张？
// 添加视频
NSItemProvider*itemProvider = [[NSItemProvider alloc] initWithItem:(NSURL*)obj typeIdentifier:(NSString*)kUTTypeQuickTimeMovie];
NSExtensionItem*extensionItem = [NSExtensionItem new];
extensionItem.attachments = [NSArrayarrayWithObject:itemProvider];[composeVC performSelector:@selector(addExtensionItem:) withObject:extensionItem];
