分享到Facebook

在iOS应用内将内容分享到Facebook，可通过接入Facebook SDK实现。官方网站：https://developers.facebook.com/docs/sharing/ios
接入Facebook SDK这里不做介绍。
可分享的内容为链接、图片、视频、多媒体（图片+视频），还可为分享的视频添加话题。
每一种分享内容都有对应的shareContent类型，并通过shareDialog分享到Facebook

分享链接：

FBSDKShareLinkContent *content = [[FBSDKShareLinkContent alloc] init];
content.contentURL = [NSURL URLWithString:@"https://developers.facebook.com"];
FBSDKShareDialog *dialog = [[FBSDKShareDialog alloc] init];
dialog.fromViewController = self;
dialog.content = content;
dialog.mode = FBSDKShareDialogModeShareSheet;
[dialog show];

分享图片

• 图片必须小于12MB
• 可分享多张图片

NSMutableArray* photos = [[NSMutableArray alloc] initWithCapacity:images.count];
for (UIImage* image in images) {
     FBSDKSharePhoto* photo = [[FBSDKSharePhoto alloc] init];
     photo.image = image;
     photo.userGenerated = YES;
        
     [photos addObject:photo];
}
    
FBSDKSharePhotoContent* content = [[FBSDKSharePhotoContent alloc] init];
content.photos = photos;
FBSDKShareDialog *dialog = [[FBSDKShareDialog alloc] init];
dialog.fromViewController = self;
dialog.content = content;
dialog.mode = FBSDKShareDialogModeShareSheet;
[dialog show];

分享本地视频

• 视频大小必须小于 50MB。

FBSDKShareVideo *video = [[FBSDKShareVideo alloc] init];
video.videoURL = url;   //亲测该URL必须是相册视频URL，如果是[NSURL fileURLWithPath:filePath],分享不了，必须写入相册
FBSDKShareVideoContent *content = [[FBSDKShareVideoContent alloc] init];
content.video = video;
content.hashtag = [FBSDKHashtag hashtagWithString:hashTag];  //还可加上话题，字符串必须带有#，只能带一个话题

同时分享图片和视频

• 用户使用的 iOS 版本至少应为 7.0。
• 分享内容的用户应安装版本 52.0 或以上的 iOS 版 Facebook 客户端。
• 照片大小必须小于 12MB，视频大小必须小于 50MB。
• 用户最多可以分享 1 个视频加 29 张照片，或最多分享 30 张照片。

FBSDKSharePhoto *photo = [FBSDKSharePhoto photoWith...
FBSDKShareVideo *video = [FBSDKShareVideo videoWith...
FBSDKShareMediaContent *content = [FBSDKShareMediaContent new];
content.media = @[photo, video];

分享到WhatsApp

分享内容到WhatsApp，只能通过openURL和原生系统分享的方式，官方网站：https://faq.whatsapp.com/en/iphone/23559013

分享文字

• 分享文字使用的是openURL的方式，如果文字中带有链接，也能识别出是链接

NSString *urlString = [NSString stringWithFormat:@"whatsapp://send?text=%@", encodeText];
BOOL ret = [[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlString]];
if (ret) {

} else {
  NSLog("failed to share");
}

分享图片

分享图片只能使用iOS的系统分享，采用UIDocumentInteractionController

NSString *savePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/whatsAppTmp.wai"];
[UIImageJPEGRepresentation(image, 1.0) writeToFile:savePath atomically:YES];
UIDocumentInteractionController *documentInteractionController =
            [UIDocumentInteractionController interactionControllerWithURL:[NSURL fileURLWithPath:savePath]];
documentInteractionController.UTI = @"net.whatsapp.image";
documentInteractionController.delegate = self;
BOOL success = [documentInteractionController presentOpenInMenuFromRect:CGRectZero inView:viewController.view animated:YES];

分享本地视频

• 除了文字之外，分享其他内容到WhatsApp只能调用系统分享，以URL的形式
• 不知道为啥UIDocumentInteractionController 分享不了视频，只能用UIActivityViewController了

NSMutableArray* items = [NSMutableArray new];
NSURL *url =  [NSURL fileURLWithPath:filePath];   //filePath为是本地视频路径，可以是沙盒路径，也可以是文件目录路径
if (url) {
      [items addObject:url];
}
UIActivityViewController *activityVC = [[UIActivityViewController alloc] initWithActivityItems:items applicationActivities:nil];
activityVC.excludedActivityTypes = @[ UIActivityTypePostToFacebook, UIActivityTypePostToTwitter ];
if ([SystemInfo isPad]) {
   if ([activityVC respondsToSelector:@selector(popoverPresentationController)]) {
          // iOS8
       activityVC.popoverPresentationController.sourceView = viewController.view;
       activityVC.popoverPresentationController.sourceRect =
       CGRectMake(viewController.view.frame.size.width * 4 / 5, viewController.view.frame.size.height - 80, 0, 0);
       activityVC.popoverPresentationController.permittedArrowDirections = UIPopoverArrowDirectionAny;
    }
}

分享到Instagram

分享图片

分享图片通过存入相册再分享

分享视频

分享视频到Instagram，必须通过相册URL

NSURL *movieURL = [NSURL fileURLWithPath:filePath];  //filePath为本地视频的路径
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library writeVideoAtPathToSavedPhotosAlbum:movieURL completionBlock:^(NSURL *assetURL, NSError *error) {
    if (error || !assetURL) {
        NSLog(@"write video to album error");
    }
    NSString *assetPath = [[assetURL absoluteString] stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet alphanumericCharacterSet]];
    NSString *captionItem = [caption stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet alphanumericCharacterSet]];
    NSURL *instagramURL = [NSURL URLWithString:[NSString stringWithFormat:@"instagram://library?AssetPath=%@&InstagramCaption=%@", assetPath, captionItem]];            
    BOOL ret = [[UIApplication sharedApplication] openURL:instagramURL];
    if (ret) {
    } else {
        NSLog("failed to share");
    }
}];

分享到VK

在iOS应用内分享内容到VK，由VKsdk支持，sdk支持分享链接、文字和图片，通过VKShareDialogController进行交互，官方网站：https://vk.com/dev/ios_sdk
而本地视频只能通过系统原生分享的方式，传入相册视频url进行分享

通过sdk进行分享

VKShareDialogController * shareDialog = [VKShareDialogController new]; 
shareDialog.text = @"This post created using #vksdk #ios"; 
shareDialog.vkImages = @[@"-10889156_348122347",@"7840938_319411365",@"-60479154_333497085"]; 
shareDialog.shareLink = [[VKShareLink alloc] initWithTitle:@"Super puper link, but nobody knows" link:[NSURL URLWithString:@"https://vk.com/dev/ios_sdk"]]; 
[shareDialog setCompletionHandler:^(VKShareDialogControllerResult result) { 
    [self dismissViewControllerAnimated:YES completion:nil]; 
}]; 
[self presentViewController:shareDialog animated:YES completion:nil];