1.Share Extension
在 iOS 8 之前，用户只有 Facebook,Twitter 等有限的几个分享选项可以选择。如果希望将内容分享到 Pinterest ，开发者则需要一些额外的努力。在 iOS 8 中，开发者可以创建自定义的分享选项，将你的应用添加到系统分享的队列中。
image
Share扩展效果图
2. 转入正题 － Share Extension
本篇文章主要是探讨Share Extension的开发与使用。下面会结合一个例子对其做一个全面的探讨和深入的了解。
2.1 创建Share Extension扩展Target
** 注：扩展不能单独创建，必须依赖于应用工程项目，因此如果你还没有创建一个应用工程，先去创建一个。**
1、打开项目设置，在TARGETS侧栏地下点击“＋”号来创建一个新的Target，如图：
image
添加Target
2、然后选择”iOS” -> “Application Extension” -> “Share Extension”，点击“Next”。如图：
image
创建Share扩展
3、给扩展起个名字，这里填写了“Share”，点击“Finish”。如图：
image
填写扩展信息
4、这时候会提示创建一个Scheme，点击“Activate”。如图：
image
那么，直到这里创建Share Extension的工作就算是完成了。接下来可以先进行一下编译运行。这里跟做App开发的时候会稍微有点不一样。因为Extension是需要Host App（宿主应用）来运行的。所以，XCode中会弹出界面让我们选择一个iOS的App来运行Extension。如图：
image
选择宿主应用
这里我选择了XCode建议的应用Safari，然后点击“Run”来进行调试运行。XCode会启动Safari，如图：
image
能看到Safari中间的分享按钮是灰色不可用的。别急，你还没打开一个网页呢_。我们随便点开一个网页，可以看到分享按钮变为激活状态。点击分享按钮就会弹出分享菜单，如图：
image
运行效果图
可以看到刚才建立的Share扩展已经显示在面板上了，如果你没有发现自己的扩展，那么你可以将菜单滑动到最右边，在“更多”选项中激活自己的扩展。如图：
1804600-075f9ccc018d92e7.png
我们点击自己创建的分享项，其弹出一个分享窗口。如图：
image
分享界面效果图
2.2. 配置Share Extension
接下来我们需要给他一些设置。我们展开XCode左侧栏的Share目录，找到Info.plist文件。如：
image
扩展Info.plist
我们只需要关注以下几个字段的设置：
6C4A5F11-0A3A-4ADB-99CB-21D2C23C298E.png
对于不同的应用里面有可能出现只允许接受某种类型的内容，那么Share Extension就不能一直出现在分享菜单中，因为不同的应用提供的分享内容不一样，这就需要通过设置NSExtensionActivationRule字段来决定Share Extension是否显示。例如，只想接受其他应用分享链接到自己的应用，那么可以通过下面的步骤来设置：
将NSExtensionActivationRule字段类型由String改为Dictionary。
展开NSExtensionActivationRule字段，创建其子项NSExtensionActivationSupportsWebURLWithMaxCount，并设置一个限制数量。
调整后如下图所示：
image
Info.plist
2.3 处理Share Extension中的数据
其实在Share Extension中默认都会有一个数据展现的UI界面。该界面继承SLComposeServiceViewController这个类型，如：
@interface ShareViewController : SLComposeServiceViewController
@end
其展现效果，如图：
image
分享界面
顶部包括了标题、取消（Cancel）按钮和提交（Post）按钮。然后下面跟着左边就是一个文本编辑框，右边就是一个图片显示控件。那么，每当用户点击取消按钮或者提交按钮时，都会分别触发下面的方法：
/**
* 点击取消按钮
*/
- (void)didSelectCancel
{
[super didSelectCancel];
}
/**
* 点击提交按钮
*/
- (void)didSelectPost
{
// This is called after the user selects Post. Do the upload of contentText and/or NSExtensionContext attachments.
// Inform the host that we're done, so it un-blocks its UI. Note: Alternatively you could call super's -didSelectPost, which will similarly complete the extension context.
[self.extensionContext completeRequestReturningItems:@[] completionHandler:nil];
}
在这两个方法里面可以进行一些自定义的操作。一般情况下，当用户点击提交按钮的时候，扩展要做的事情就是要把数据取出来，并且放入一个与Containing App（** 容器程序，尽管苹果开放了Extension，但是在iOS中extension并不能单独存在，要想提交到AppStore，必须将Extension包含在一个App中提交，并且App的实现部分不能为空,这个包含Extension的App就叫Containing app。Extension会随着Containing App的安装而安装，同时随着ContainingApp的卸载而卸载。**）共享的数据介质中（包括NSUserDefault、Sqlite、CoreData），要跟容器程序进行数据交互需要借助AppGroups服务，下面的章节会对这块进行详细说明。下面先来看看怎么获取扩展中的数据。
在ShareExtension中，UIViewController包含一个extensionContext这样的上下文对象：
@interface UIViewController(NSExtensionAdditions) <NSExtensionRequestHandling>
// Returns the extension context. Also acts as a convenience method for a view controller to check if it participating in an extension request.
@property (nullable, nonatomic,readonly,strong) NSExtensionContext *extensionContext NS_AVAILABLE_IOS(8_0);
@end
通过操作它就可以获取到分享的数据，返回宿主应用的界面等操作。我们可以先看一下extensionContext的定义。
NS_CLASS_AVAILABLE(10_10, 8_0)
@interface NSExtensionContext : NSObject
// The list of input NSExtensionItems associated with the context. If the context has no input items, this array will be empty.
@property(readonly, copy, NS_NONATOMIC_IOSONLY) NSArray *inputItems;
// Signals the host to complete the app extension request with the supplied result items. The completion handler optionally contains any work which the extension may need to perform after the request has been completed, as a background-priority task. The `expired` parameter will be YES if the system decides to prematurely terminate a previous non-expiration invocation of the completionHandler. Note: calling this method will eventually dismiss the associated view controller.
- (void)completeRequestReturningItems:(nullable NSArray *)items completionHandler:(void(^ __nullable)(BOOL expired))completionHandler;
// Signals the host to cancel the app extension request, with the supplied error, which should be non-nil. The userInfo of the NSError will contain a key NSExtensionItemsAndErrorsKey which will have as its value a dictionary of NSExtensionItems and associated NSError instances.
- (void)cancelRequestWithError:(NSError *)error;
// Asks the host to open an URL on the extension's behalf
- (void)openURL:(NSURL *)URL completionHandler:(void (^ __nullable)(BOOL success))completionHandler;
@end
// Key in userInfo. Value is a dictionary of NSExtensionItems and associated NSError instances.
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionItemsAndErrorsKey NS_AVAILABLE(10_10, 8_0);
// The host process will enter the foreground
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionHostWillEnterForegroundNotification NS_AVAILABLE_IOS(8_2);
// The host process did enter the background
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionHostDidEnterBackgroundNotification NS_AVAILABLE_IOS(8_2);
// The host process will resign active status (stop receiving events), the extension may be suspended
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionHostWillResignActiveNotification NS_AVAILABLE_IOS(8_2);
// The host process did become active (begin receiving events)
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionHostDidBecomeActiveNotification NS_AVAILABLE_IOS(8_2);
NSExtensionContext的结构比较简单，包含一个属性和三个方法。其说明如下：
image
类的下面还定义了一些通知，这些通知都是跟宿主程序的行为相关，在设计扩展的时候可以根据这些通知来进行对应的操作。其说明如下：
image
2.3.1 从inputItems中获取数据
inputItems是包含NSExtensionItem类型对象的数组。那么，要处理里面的数据还得先来了解一下NSExtensionItem的结构：
@interface NSExtensionItem : NSObject<NSCopying, NSSecureCoding>
// (optional) title for the item
@property(nullable, copy, NS_NONATOMIC_IOSONLY) NSAttributedString *attributedTitle;
// (optional) content text
@property(nullable, copy, NS_NONATOMIC_IOSONLY) NSAttributedString *attributedContentText;
// (optional) Contains images, videos, URLs, etc. This is not meant to be an array of alternate data formats/types, but instead a collection to include in a social media post for example. These items are always typed NSItemProvider.
@property(nullable, copy, NS_NONATOMIC_IOSONLY) NSArray *attachments;
// (optional) dictionary of key-value data. The key/value pairs accepted by the service are expected to be specified in the extension's Info.plist. The values of NSExtensionItem's properties will be reflected into the dictionary.
@property(nullable, copy, NS_NONATOMIC_IOSONLY) NSDictionary *userInfo;
@end
// Keys corresponding to properties exposed on the NSExtensionItem interface
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionItemAttributedTitleKey NS_AVAILABLE(10_10, 8_0);
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionItemAttributedContentTextKey NS_AVAILABLE(10_10, 8_0);
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionItemAttachmentsKey NS_AVAILABLE(10_10, 8_0);
image
从上面的定义可以看出除了文本内容，其他类型的内容都是作为附件存储的，而附件又是封装在一个叫NSItemProvider的类型中，其定义如下：
typedef void (^NSItemProviderCompletionHandler)(__nullable id <NSSecureCoding> item, NSError * __null_unspecified error);
typedef void (^NSItemProviderLoadHandler)(__null_unspecified NSItemProviderCompletionHandler completionHandler, __null_unspecified Class expectedValueClass, NSDictionary * __null_unspecified options);
// An NSItemProvider is a high level abstraction for file-like data objects supporting multiple representations and preview images.
NS_CLASS_AVAILABLE(10_10, 8_0)
@interface NSItemProvider : NSObject <NSCopying>
// Initialize an NSItemProvider with a single handler for the given item.
- (instancetype)initWithItem:(nullable id <NSSecureCoding>)item typeIdentifier:(nullable NSString *)typeIdentifier NS_DESIGNATED_INITIALIZER;
// Initialize an NSItemProvider with load handlers for the given file URL, and the file content.
- (nullable instancetype)initWithContentsOfURL:(null_unspecified NSURL *)fileURL;
// Sets a load handler block for a specific type identifier. Handlers are invoked on demand through loadItemForTypeIdentifier:options:completionHandler:. To complete loading, the implementation has to call the given completionHandler. Both expectedValueClass and options parameters are derived from the completionHandler block.
- (void)registerItemForTypeIdentifier:(NSString *)typeIdentifier loadHandler:(NSItemProviderLoadHandler)loadHandler;
// Returns the list of registered type identifiers
@property(copy, readonly, NS_NONATOMIC_IOSONLY) NSArray *registeredTypeIdentifiers;
// Returns YES if the item provider has at least one item that conforms to the supplied type identifier.
- (BOOL)hasItemConformingToTypeIdentifier:(NSString *)typeIdentifier;
// Loads the best matching item for a type identifier. The client's expected value class is automatically derived from the blocks item parameter. Returns an error if the returned item class does not match the expected value class. Item providers will perform simple type coercions (eg. NSURL to NSData, NSURL to NSFileWrapper, NSData to UIImage).
- (void)loadItemForTypeIdentifier:(NSString *)typeIdentifier options:(nullable NSDictionary *)options completionHandler:(nullable NSItemProviderCompletionHandler)completionHandler;
@end
// Common keys for the item provider options dictionary.
FOUNDATION_EXTERN NSString * __null_unspecified const NSItemProviderPreferredImageSizeKey NS_AVAILABLE(10_10, 8_0); // NSValue of CGSize or NSSize, specifies image size in pixels.
@interface NSItemProvider(NSPreviewSupport)
// Sets a custom preview image handler block for this item provider. The returned item should preferably be NSData or a file NSURL.
@property(nullable, copy, NS_NONATOMIC_IOSONLY) NSItemProviderLoadHandler previewImageHandler NS_AVAILABLE(10_10, 8_0);
// Loads the preview image for this item by either calling the supplied preview block or falling back to a QuickLook-based handler. This method, like loadItemForTypeIdentifier:options:completionHandler:, supports implicit type coercion for the item parameter of the completion block. Allowed value classes are: NSData, NSURL, UIImage/NSImage.
- (void)loadPreviewImageWithOptions:(null_unspecified NSDictionary *)options completionHandler:(null_unspecified NSItemProviderCompletionHandler)completionHandler NS_AVAILABLE(10_10, 8_0);
@end
// Keys used in property list items received from or sent to JavaScript code
// If JavaScript code passes an object to its completionFunction, it will be placed into an item of type kUTTypePropertyList, containing an NSDictionary, under this key.
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionJavaScriptPreprocessingResultsKey NS_AVAILABLE(10_10, 8_0);
// Arguments to be passed to a JavaScript finalize method should be placed in an item of type kUTTypePropertyList, containing an NSDictionary, under this key.
FOUNDATION_EXTERN NSString * __null_unspecified const NSExtensionJavaScriptFinalizeArgumentKey NS_AVAILABLE_IOS(8_0);
// Errors
// Constant used by NSError to distinguish errors belonging to the NSItemProvider domain
FOUNDATION_EXTERN NSString * __null_unspecified const NSItemProviderErrorDomain NS_AVAILABLE(10_10, 8_0);
// NSItemProvider-related error codes
typedef NS_ENUM(NSInteger, NSItemProviderErrorCode) {
NSItemProviderUnknownError = -1,
NSItemProviderItemUnavailableError = -1000,
NSItemProviderUnexpectedValueClassError = -1100,
NSItemProviderUnavailableCoercionError NS_AVAILABLE(10_11, 9_0) = -1200
} NS_ENUM_AVAILABLE(10_10, 8_0);
NSItemProvider结构说明
image
由此可见，其结构如下图所示：
image
层次结构图
为了要取到宿主程序提供的数组，那么只要关注loadItemTypeIdentifier:options:completionHandler方法的使用即可。有了上面的了解，那么接下来就是对inputItems进行数据分析并提取了，这里以一个链接的分享为例，改写视图控制器中的didSelectPost方法。看下面的代码：
- (void)didSelectPost
{
__block BOOL hasExistsUrl = NO;
[self.extensionContext.inputItems enumerateObjectsUsingBlock:^(NSExtensionItem * _Nonnull extItem, NSUInteger idx, BOOL * _Nonnull stop) {
[item.attachments enumerateObjectsUsingBlock:^(NSItemProvider * _Nonnull itemProvider, NSUInteger idx, BOOL * _Nonnull stop) {
if ([itemProvider hasItemConformingToTypeIdentifier:@"public.url"])
{
[itemProvider loadItemForTypeIdentifier:@"public.url"
options:nil
completionHandler:^(id<NSSecureCoding> _Nullable item, NSError * _Null_unspecified error) {
if ([(NSObject *)item isKindOfClass:[NSURL class]])
{
NSLog(@"分享的URL = %@", item);
}
}];
hasExistsUrl = YES;
*stop = YES;
}
}];
if (hasExistsUrl)
{
*stop = YES;
}
}];
// This is called after the user selects Post. Do the upload of contentText and/or NSExtensionContext attachments.
// Inform the host that we're done, so it un-blocks its UI. Note: Alternatively you could call super's -didSelectPost, which will similarly complete the extension context.
// [self.extensionContext completeRequestReturningItems:@[] completionHandler:nil];
}
上面的例子中遍历了extensionContext的inputItems数组中所有NSExtensionItem对象，然后从这些对象中遍历attachments数组中的所有NSItemProvider对象。匹配第一个包含public.url标识的附件（具体要匹配什么资源，数量是多少皆有自己的业务所决定）。** 注意：在上面代码中注释了[self.extensionContext completeRequestReturningItems:@[] completionHandler:nil];这行代码，主要是使到视图控制器不被关闭，等到实现相应的处理后再进行调用该方法，对分享视图进行关闭。** 在下面的章节会说明这一点。
2.3.2 将分享数据传递给容器程序
上面章节已经讲述了如何取得宿主应用所分享的内容。那么，接下来就是将这些内容传递给容器程序进行相应的操作（如：在一款社交应用中，可能会为取得的分享内容发布一条用户动态）。在默认情况下，iOS的应用是存在一个沙盒里面的，不允许应用与应用直接进行数据的交互。为此，苹果提供了一项叫App Groups的服务，该服务允许开发者可以在自己的应用之间通过NSUserDefaults、NSFileManager或者CoreData来进行相互的数据传输。下面介绍如何激活App Groups服务：
首先要有一个独立的AppID（带通配符＊号的AppID是不允许激活App Groups的）
image
使用AppGroup
然后打开容器应用的项目配置的Capabilities页签，激活App Groups特性，如图：
image
激活AppGroup特性
点击＋号添加一个App Groups，点击OK按钮
image
设置Group名称
创建完成后，XCode会自动把应用添加到新建的分组中。如图：
image
容器程序启用AppGroup
上述步骤完成后，容器程序的App Groups已经算是设置完成。然后轮到Share Extension插件需要激活App Groups服务，设置步骤跟容器程序相同，唯一不同的是，插件不需要创建新的App Group，只要加入到容器程序刚才创建的Group即可（这里可以理解为，哪些应用要实现共享数据，那么他们必须在同一个Group里面）。如图：
image
扩展程序启用AppGroup
至此，应用和扩展的App Groups服务都已经启动，现在就要进行分享内容的传输操作。下面分别介绍一下NSUserDefaults、NSFileManager以及CoreData三种方式是如何实现App Groups下的数据操作：
NSUserDefaults：要想设置或访问Group的数据，不能在使用standardUserDefaults方法来获取一个NSUserDefaults对象了。应该使用initWithSuiteName:方法来初始化一个NSUserDefaults对象，其中的SuiteName就是创建的Group的名字，然后利用这个对象来实现，跨应用的数据读写，代码如下：
//初始化一个供App Groups使用的NSUserDefaults对象
NSUserDefaults *userDefaults = [[NSUserDefaults alloc] initWithSuiteName:@"group.cn.vimfung.ShareExtensionDemo"];
//写入数据
[userDefaults setValue:@"value" forKey:@"key"];
//读取数据
NSLog(@"%@", [userDefaults valueForKey:@"key"]);
NSFileManager：通过调用 containerURLForSecurityApplicationGroupIdentifier:方法可以获得AppGroup的共享目录，然后在此目录的基础上实现任意的文件操作。代码如下：
//获取分组的共享目录
NSURL *groupURL = [[NSFileManager defaultManager] containerURLForSecurityApplicationGroupIdentifier:@"group.cn.vimfung.ShareExtensionDemo"];
NSURL *fileURL = [groupURL URLByAppendingPathComponent:@"demo.txt"];
//写入文件
[@"abc" writeToURL:fileURL atomically:YES encoding:NSUTF8StringEncoding error:nil];
//读取文件
NSString *str = [NSString stringWithContentsOfURL:fileURL encoding:NSUTF8StringEncoding error:nil];
NSLog(@"str = %@", str);
CoreData：其实CoreData是基于NSFileManager取得共享目录后来实现数据共享的。即在初始化CoreData时，先使用NSFileManager取得共享目录，然后再指定共享目录为存储数据文件的目录（如存储的sqlite文件）。代码如下：
//获取分组的共享项目
NSURL *containerURL = [[NSFileManager defaultManager] containerURLForSecurityApplicationGroupIdentifier:@"group.cn.vimfung.ShareExtensionDemo"];
NSURL *storeURL = [containerURL URLByAppendingPathComponent:@"DataModel.sqlite"];
//初始化持久化存储调度器
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"DataModel" withExtension:@"momd"];
NSManagedObjectModel *model = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
NSPersistentStoreCoordinator *coordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:model];
[coordinator addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:storeURL
options:nil
error:nil];
//创建受控对象上下文
NSManagedObjectContext *context = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
[context performBlockAndWait:^{
[context setPersistentStoreCoordinator:coordinator];
}];
为了方便演示，这里会使用NSUserDefault来直接把取到的url地址保存起来。代码如下所示：
/**
* 点击提交按钮
*/
- (void)didSelectPost
{
__block BOOL hasExistsUrl = NO;
[self.extensionContext.inputItems enumerateObjectsUsingBlock:^(NSExtensionItem * _Nonnull extItem, NSUInteger idx, BOOL * _Nonnull stop) {
[item.attachments enumerateObjectsUsingBlock:^(NSItemProvider * _Nonnull itemProvider, NSUInteger idx, BOOL * _Nonnull stop) {
if ([itemProvider hasItemConformingToTypeIdentifier:@"public.url"])
{
[itemProvider loadItemForTypeIdentifier:@"public.url"
options:nil
completionHandler:^(id<NSSecureCoding> _Nullable item, NSError * _Null_unspecified error) {
if ([(NSObject *)item isKindOfClass:[NSURL class]])
{
NSLog(@"分享的URL = %@", item);
NSUserDefaults *userDefaults = [[NSUserDefaults alloc] initWithSuiteName:@"group.cn.vimfung.ShareExtensionDemo"];
[userDefaults setValue: ((NSURL *)item).absoluteString forKey:@"share-url"];
//用于标记是新的分享
[userDefaults setBool:YES forKey:@"has-new-share"];
}
}];
hasExistsUrl = YES;
*stop = YES;
}
}];
if (hasExistsUrl)
{
*stop = YES;
}
}];
// This is called after the user selects Post. Do the upload of contentText and/or NSExtensionContext attachments.
// Inform the host that we're done, so it un-blocks its UI. Note: Alternatively you could call super's -didSelectPost, which will similarly complete the extension context.
// [self.extensionContext completeRequestReturningItems:@[] completionHandler:nil];
}
2.3.3 做好分享插件的提示操作
默认情况下，如果用户点击Post按钮后，分享界面就会消失，用户可以继续对宿主程序进行操作。这些都要靠NSExtensionContextd的completeRequestReturningItems:completionHandler:方法来实现。现在，由于在didSelectPost方法中加入了分享内容的处理，由于获取附件是一个异步过程，那么，就需要做好界面上的提示。否则，分享界面消失后由于没有操作提示，会使用户误以为界面进行卡死的状态，其实是分享内容还没有处理完成。接下来就是优化UI上的提示操作，代码如下：
/**
* 点击提交按钮
*/
- (void)didSelectPost
{
//加载动画初始化
UIActivityIndicatorView *activityIndicatorView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
activityIndicatorView.frame = CGRectMake((self.view.frame.size.width - activityIndicatorView.frame.size.width) / 2,
(self.view.frame.size.height - activityIndicatorView.frame.size.height) / 2,
activityIndicatorView.frame.size.width,
activityIndicatorView.frame.size.height);
activityIndicatorView.autoresizingMask = UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleBottomMargin;
[self.view addSubview:activityIndicatorView];
//激活加载动画
[activityIndicatorView startAnimating];
__weak ShareViewController *theController = self;
__block BOOL hasExistsUrl = NO;
[self.extensionContext.inputItems enumerateObjectsUsingBlock:^(NSExtensionItem * _Nonnull extItem, NSUInteger idx, BOOL * _Nonnull stop) {
[extItem.attachments enumerateObjectsUsingBlock:^(NSItemProvider * _Nonnull itemProvider, NSUInteger idx, BOOL * _Nonnull stop) {
if ([itemProvider hasItemConformingToTypeIdentifier:@"public.url"])
{
[itemProvider loadItemForTypeIdentifier:@"public.url"
options:nil
completionHandler:^(id<NSSecureCoding> _Nullable item, NSError * _Null_unspecified error) {
if ([(NSObject *)item isKindOfClass:[NSURL class]])
{
NSLog(@"分享的URL = %@", item);
NSUserDefaults *userDefaults = [[NSUserDefaults alloc] initWithSuiteName:@"group.cn.vimfung.ShareExtensionDemo"];
[userDefaults setValue:((NSURL *)item).absoluteString forKey:@"share-url"];
//用于标记是新的分享
[userDefaults setBool:YES forKey:@"has-new-share"];
[activityIndicatorView stopAnimating];
[theController.extensionContext completeRequestReturningItems:@[extItem] completionHandler:nil];
}
}];
hasExistsUrl = YES;
*stop = YES;
}
}];
if (hasExistsUrl)
{
*stop = YES;
}
}];
if (!hasExistsUrl)
{
//直接退出
[self.extensionContext completeRequestReturningItems:@[] completionHandler:nil];
}
}
2.4 容器程序获取分享数据
插件的工作基本上已经全部开发完成了，接下来就是容器程序获取数据并进行操作。下面是容器程序的处理代码：
- (void)applicationDidBecomeActive:(UIApplication *)application
{
//获取共享的UserDefaults
NSUserDefaults *userDefaults = [[NSUserDefaults alloc] initWithSuiteName:@"group.cn.vimfung.ShareExtensionDemo"];
if ([userDefaults boolForKey:@"has-new-share"])
{
NSLog(@"新的分享 : %@", [userDefaults valueForKey:@"share-url"]);
//重置分享标识
[userDefaults setBool:NO forKey:@"has-new-share"];
}
}
为了方便演示，这里直接在AppDelegate中的applicationDidBecomeActive:方法中检测是否有新的分享，如果有则通过Log打印链接出来。
至此，整个Share Extension开发的过程已经完成。
2.5 提审AppStore的注意事项
扩展中的处理不能太长时间阻塞主线程（建议放入线程中处处理），否则可能导致苹果拒绝你的应用。
扩展不能单独提审，必须要跟容器程序一起提交AppStore进行审核。
提审的扩展和容器程序的Build Version要保持一致，否则在上传审核包的时候会提示警告，导致程序无法正常提审。
3. 进阶研究
3.1 对默认分享界面进行扩展
在某些情况下，在分享界面中会加入一下其它信息的显示，或者其它的选项供用户操作。如：内容要分享给什么好友、分享内容的可见权限等等。那么，默认的分享界面（ SLComposeServiceViewController）提供了相关的方法来对其进行扩展。这些方法定义如下：
#if TARGET_OS_IPHONE
/*
Configuration Item Support (account pickers, privacy selection, location, etc.)
*/
// Subclasses should implement this, and return an array of SLComposeSheetConfigurationItem instances, if if needs to display configuration items in the sheet. Defaults to nil.
- (NSArray *)configurationItems;
// Forces a reload of the configuration items table.
// This is typically only necessary for subclasses that determine their configuration items in a deferred manner (for example, in -presentationAnimationDidFinish).
// You do not need to call this after changing a configuration item property; the base class detects and reacts to that automatically.
- (void)reloadConfigurationItems;
// Presents a configuration view controller. Typically called from a configuration item's tapHandler. Only one configuration view controller is allowed at a time.
// The pushed view controller should set preferredContentSize appropriately. SLComposeServiceViewController observes changes to that property and animates sheet size changes as necessary.
- (void)pushConfigurationViewController:(UIViewController *)viewController;
// Dismisses the current configuration view controller.
- (void)popConfigurationViewController;
#endif
下面是方法的说明
image
再来看一下SLComposeSheetConfigurationItem的声明：
typedef void (^SLComposeSheetConfigurationItemTapHandler)(void);
// Represents a user-configurable option for the compose session.
// For allowing the user to choose which account to post from, what privacy settings to use, etc.
SOCIAL_CLASS_AVAILABLE(NA, 8_0)
@interface SLComposeSheetConfigurationItem : NSObject
// Designated initializer
- (instancetype)init NS_DESIGNATED_INITIALIZER;
@property (nonatomic, copy) NSString *title; // The displayed name of the option.
@property (nonatomic, copy) NSString *value; // The current value/setting of the option.
@property (nonatomic, assign) BOOL valuePending; // Default is NO. set to YES to show a progress indicator. Can be used with a value too.
// Called on the main queue when the configuration item is tapped.
// Your block should not keep a strong reference to either the configuration item, or the SLComposeServiceViewController, otherwise you'll end up with a retain cycle.
@property (nonatomic, copy) SLComposeSheetConfigurationItemTapHandler tapHandler;
@end
其属性说明如下：
image
下面将通过使用这些方法来扩展UI，使插件增加两个配置项：一个是是否公开分享的配置项，该选项标识一个开关值。另外一个是公开权限设置项，在是否公开分享的开关为开时显示。可以选择分享给所有人还是好友。代码如下所示：
- (NSArray *)configurationItems {
// To add configuration options via table cells at the bottom of the sheet, return an array of SLComposeSheetConfigurationItem here.
//定义两个配置项，分别记录用户选择是否公开以及公开的权限，然后根据配置的值
static BOOL isPublic = NO;
static NSInteger act = 0;
NSMutableArray *items = [NSMutableArray array];
//创建是否公开配置项
SLComposeSheetConfigurationItem *item = [[SLComposeSheetConfigurationItem alloc] init];
item.title = @"是否公开";
item.value = isPublic ? @"是" : @"否";
__weak ShareViewController *theController = self;
__weak SLComposeSheetConfigurationItem *theItem = item;
item.tapHandler = ^{
isPublic = !isPublic;
theItem.value = isPublic ? @"是" : @"否";
[theController reloadConfigurationItems];
};
[items addObject:item];
if (isPublic)
{
//如果公开标识为YES，则创建公开权限配置项
SLComposeSheetConfigurationItem *actItem = [[SLComposeSheetConfigurationItem alloc] init];
actItem.title = @"公开权限";
switch (act)
{
case 0:
actItem.value = @"所有人";
break;
case 1:
actItem.value = @"好友";
break;
default:
break;
}
actItem.tapHandler = ^{
//设置分享权限时弹出选择界面
ShareActViewController *actVC = [[ShareActViewController alloc] init];
[theController pushConfigurationViewController:actVC];
[actVC onSelected:^(NSIndexPath *indexPath) {
//当选择完成时退出选择界面并刷新配置项。
act = indexPath.row;
[theController popConfigurationViewController];
[theController reloadConfigurationItems];
}];
};
[items addObject:actItem];
}
return items;
}
ShareActViewController实现：
@interface ShareActViewController () <UITableViewDelegate, UITableViewDataSource>
@property (nonatomic, strong) void (^selectedHandler) ();
@end
@implementation ShareActViewController
- (void)viewDidLoad
{
[super viewDidLoad];
UITableView *tableView = [[UITableView alloc] initWithFrame:self.view.bounds];
tableView.backgroundColor = [UIColor clearColor];
tableView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
tableView.dataSource = self;
tableView.delegate = self;
[tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"Cell"];
[self.view addSubview:tableView];
}
- (void)onSelected:(void(^)(NSIndexPath *indexPath))handler
{
self.selectedHandler = handler;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 2;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
cell.backgroundColor = [UIColor clearColor];
switch (indexPath.row)
{
case 0:
cell.textLabel.text = @"所有人";
break;
case 1:
cell.textLabel.text = @"好友";
break;
default:
break;
}
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (self.selectedHandler)
{
self.selectedHandler (indexPath);
}
}
在分享插件界面中重写了configurationItems方法，然后定义了两个配置项属性，分别是是否公开标识isPublic和公开权限act。然后创建是否公开的SLComposeSheetConfigurationItem配置项和根据isPublic的值来判断是否创建公开权限配置项。其中是否公开配置点击时会变更isPublic的值，从而达到显示或隐藏公开权限配置。而公开权限配置的点击则弹出一个选择的TableView，用于选择给定的值然后返回到分享界面。
3.2 替换Share Extension中的默认分享界面
如果通过扩展SLComposeServiceViewController还不能满足需求的情况下，这时候就需要自己设计一个分享视图控制器来替换默认的SLComposeServiceViewController。
首先，创建一个自定义视图控制器，如：CustomShareViewController。
然后打开扩展的Info.plist文件，删除NSExtensionMainStoryboard属性并增加一项NSExtensionPrincipalClass属性并指向CustomShareViewController（注：这里没有使用Storyboard所以要删除该属性），如图：
image
Info.plist
接下来根据实际的需要来设计分享视图的展示与交互形式。
然后调用CustomShareViewController的extensionContext属性来控制扩展的提交与取消等操作（注：由于扩展中导入了关于ExtensionContext的UIViewController类目，因此，每个ViewController都带有extensionContext属性）。
为了演示的简单性，下面的代码会通过extensionContext获取到url后，给到自定义分享视图的Label中显示，同时也提供一个提交和取消按钮，用于用户对分享内容的操作。代码如下：
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
//定义一个容器视图来存放分享内容和两个操作按钮
UIView *container = [[UIView alloc] initWithFrame:CGRectMake((self.view.frame.size.width - 300) / 2, (self.view.frame.size.height - 175) / 2, 300, 175)];
container.layer.cornerRadius = 7;
container.layer.borderColor = [UIColor lightGrayColor].CGColor;
container.layer.borderWidth = 1;
container.layer.masksToBounds = YES;
container.backgroundColor = [UIColor whiteColor];
container.autoresizingMask = UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleBottomMargin;
[self.view addSubview:container];
//定义Post和Cancel按钮
UIButton *cancelBtn = [UIButton buttonWithType:UIButtonTypeSystem];
[cancelBtn setTitle:@"Cancel" forState:UIControlStateNormal];
cancelBtn.frame = CGRectMake(8, 8, 65, 40);
[cancelBtn addTarget:self action:@selector(cancelBtnClickHandler:) forControlEvents:UIControlEventTouchUpInside];
[container addSubview:cancelBtn];
UIButton *postBtn = [UIButton buttonWithType:UIButtonTypeSystem];
[postBtn setTitle:@"Post" forState:UIControlStateNormal];
postBtn.frame = CGRectMake(container.frame.size.width - 8 - 65, 8, 65, 40);
[postBtn addTarget:self action:@selector(postBtnClickHandler:) forControlEvents:UIControlEventTouchUpInside];
[container addSubview:postBtn];
//定义一个分享链接标签
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(8,
cancelBtn.frame.origin.y + cancelBtn.frame.size.height + 8,
container.frame.size.width - 16,
container.frame.size.height - 16 - cancelBtn.frame.origin.y - cancelBtn.frame.size.height)];
label.numberOfLines = 0;
label.textAlignment = NSTextAlignmentCenter;
[container addSubview:label];
//获取分享链接
__block BOOL hasGetUrl = NO;
[self.extensionContext.inputItems enumerateObjectsUsingBlock:^(NSExtensionItem * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
[obj.attachments enumerateObjectsUsingBlock:^(NSItemProvider * _Nonnull itemProvider, NSUInteger idx, BOOL * _Nonnull stop) {
if ([itemProvider hasItemConformingToTypeIdentifier:@"public.url"])
{
[itemProvider loadItemForTypeIdentifier:@"public.url" options:nil completionHandler:^(id<NSSecureCoding> _Nullable item, NSError * _Null_unspecified error) {
if ([(NSObject *)item isKindOfClass:[NSURL class]])
{
dispatch_async(dispatch_get_main_queue(), ^{
label.text = ((NSURL *)item).absoluteString;
});
}
}];
hasGetUrl = YES;
*stop = YES;
}
*stop = hasGetUrl;
}];
}];
}
- (void)cancelBtnClickHandler:(id)sender
{
//取消分享
[self.extensionContext cancelRequestWithError:[NSError errorWithDomain:@"CustomShareError" code:NSUserCancelledError userInfo:nil]];
}
- (void)postBtnClickHandler:(id)sender
{
//执行分享内容处理
[self.extensionContext completeRequestReturningItems:@[] completionHandler:nil];
}
效果如下图所示：
image
效果图
最后附上Demo地址
