iOS 6 - UIActivityViewController项目

Question

希望大家都知道iOS 6包含新风格的ActionSheet（UIActivityViewController）。可以通过字符串、url、图像等参数来启动UIActivityViewController。以下是代码片段（其中items是带有字符串和url参数的数组）。

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

但是，我们是否可以在选择不同的分享选项（如邮件、Facebook或Twitter）时分配不同的参数呢？

一种方法是实现UIActivityItemSource，其中我们需要实现源方法。

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

该函数始终返回一个字符串值。但我需要传递一个数组，以便我可以分配各种参数，如URL、图像和标题。

你有什么想法如何实现这个目标吗？

- ashok

Answer 1

你无法更改内置的iOS UIActivityViewController项目，如Mail、Facebook和Twitter。为了在UIActivityViewController中实现自定义操作，您必须为每个自定义活动创建一个自定义的UIActivity子类。这是一个示例：

- (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;
}

这是一个UIActivity的子类示例，介绍了您需要覆盖的方法的文档，以处理自定义数据/操作。

#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

- Jeremy Fox

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如果你要给一个回答点踩，至少有礼貌地解释一下为什么。否则，这样做有什么意义呢？ - Jeremy Fox