iOS 6 - UIActivityViewController 项目

iOS 6 - UIActivityViewController items

提问by ashok

Hope everyone is aware of iOS 6 contains new style of ActionSheet (UIActivityViewController).The UIActivityViewControllercan be initiated with the paramentes like string, url, image etc. Below is the code snippet for that (where items is an array with string and url params).

希望每个人都知道的iOS 6中包含的新风格ActionSheet (UIActivityViewController).的UIActivityViewController都可以用类似的字符串，网址，图像等。下面的paramentes发起针对该代码段（其中的项目是用绳子和网址参数的数组）。

UIActivityViewController *activityVC = [[UIActivityViewController alloc] initWithActivityItems:items applicationActivities:nil];

But, is there any way that we can assign different parameters when we select different share options like Mail, Facebook or Twitter?

但是，当我们选择不同的共享选项（例如 Mail、Facebook 或 Twitter）时，有什么方法可以分配不同的参数？

One method is we can implement UIActivityItemSource, where we need to implement the source methods

一种方法是我们可以实现UIActivityItemSource，这里我们需要实现源方法

- (id)activityViewController:(UIActivityViewController *)activityViewController itemForActivityType:(NSString *)activityType

which always returns a string value. But I need to pass an Array, so that I can assign various parameters like URL, image and a title.

它总是返回一个字符串值。但是我需要传递一个数组，以便我可以分配各种参数，例如 URL、图像和标题。

Any idea how we can achieve this?

知道我们如何实现这一目标吗？

回答by Jeremy Fox

You can not change anything for the built in iOS UIActivityViewController items like Mail, Facebook and Twitter. In order to implement custom actions for items in your UIActivityViewController you must create a custom subclass of UIActivity for each custom activity you want. Here is an example:

您不能对内置的 iOS UIActivityViewController 项目（如 Mail、Facebook 和 Twitter）进行任何更改。为了为 UIActivityViewController 中的项目实现自定义操作，您必须为您想要的每个自定义活动创建 UIActivity 的自定义子类。下面是一个例子：

- (UIActivityViewController *)getActivityViewController {
    MyFeedbackActivity *feedbackActivity = [[MyFeedbackActivity alloc] init];
    MyFacebookActivity *facebookActivity = [[MyFacebookActivity alloc] init];
    MyMailActivity *mailActivity = [[MyMailActivity alloc] init];

    NSArray *applicationActivities = @[feedbackActivity, facebookActivity, mailActivity];
    NSArray *activitiesItems = @[@"A string to be used for MyFeedbackActivity", @"A string to be used for MyFacebookActivity", @"A string to be used for MyMailActivity"];

    UIActivityViewController *activityVC = [[UIActivityViewController alloc] initWithActivityItems:activitiesItems applicationActivities:applicationActivities];

    // Removed un-needed activities
    activityVC.excludedActivityTypes = [[NSArray alloc] initWithObjects:
                                                     UIActivityTypeCopyToPasteboard,
                                                     UIActivityTypePostToWeibo,
                                                     UIActivityTypePostToFacebook,
                                                     UIActivityTypeSaveToCameraRoll,
                                                     UIActivityTypeCopyToPasteboard,
                                                     UIActivityTypeMail,
                                                     UIActivityTypeMessage,
                                                     UIActivityTypeAssignToContact,
                                                     nil];

    return activityVC;
}

A very limited example of a subclassed UIActivity with documentation on the methods that you will be interested in overriding to handle your custom data/actions.

一个非常有限的子类 UIActivity 示例，其中包含有关您将有兴趣覆盖以处理自定义数据/操作的方法的文档。

#import "MyFeedbackActivity.h"

@implementation MyFeedbackActivity

- (NSString *)activityType {
    return @"MyFeedbackActivity";
}

- (NSString *)activityTitle {
    return @"Feedback";
}

- (UIImage *)activityImage {
    return [UIImage imageNamed:@"feedback"];
}

- (BOOL)canPerformWithActivityItems:(NSArray *)activityItems {
    return YES;
}

- (UIViewController *)activityViewController {
    /**
     * DESCRIPTION:
     * Returns the view controller to present to the user.
     * Subclasses that provide additional UI using a view controller can override this method to return that view controller. If this method returns a valid object, the system presents the returned view controller modally instead of calling the performActivity method.
     * Your custom view controller should provide a view with your custom UI and should handle any user interactions inside those views. Upon completing the activity, do not dismiss the view controller yourself. Instead, call the activityDidFinish: method and let the system dismiss it for you.
     */
}

- (void)prepareWithActivityItems:(NSArray *)activityItems {
    /**
     * DESCRIPTION:
     * Prepares your service to act on the specified data.
     * The default implementation of this method does nothing. This method is called after the user has selected your service but before your service is asked to perform its action. Subclasses should override this method and use it to store a reference to the data items in the activityItems parameter. In addition, if the implementation of your service requires displaying additional UI to the user, you can use this method to prepare your view controller object and make it available from the activityViewController method.
     */
}

-(void)performActivity {
    /**
     * DESCRIPTION:
     * Performs the service when no custom view controller is provided.
     * The default implementation of this method does nothing. If your service does not provide any custom UI using the activityViewController method, override this method and use it to perform the activity. Your activity must operate on the data items received in the prepareWithActivityItems: method.
     * This method is called on your app's main thread. If your app can complete the activity quickly on the main thread, do so and call the activityDidFinish: method when it is done. If performing the activity might take some time, use this method to start the work in the background and then exit without calling activityDidFinish: from this method. Instead, call activityDidFinish: from your background thread after the actual work has been completed.
     */
}

@end