点击取消按钮时，这是使用UIActivityViewController调用共享选项的委托方法

Question

点击取消按钮时，这是委托方法吗？请查看下图。使用UIActivityViewController共享选项

Answer 1

UIActivityViewControllerCompletionHandler 在解除活动视图控制器之后执行的完成处理程序。

typedef void (^UIActivityViewControllerCompletionHandler)(NSString *activityType, BOOL completed);

您可以按以下方式访问它：

[activityViewControllerObj setCompletionHandler:^(NSString *activityType, BOOL completed) {
    NSLog(@"completed"); 
}];

Answer 2

NSArray * shareItems = @[message, image];
UIActivityViewController * avc = [[UIActivityViewController alloc] initWithActivityItems:shareItems applicationActivities:nil];
[avc setCompletionHandler:^(NSString *activityType, BOOL completed) {
    //finish your code when the user finish or dismiss...
    if (completed) {
        NSLog(@"avc done");
    } else {
        NSLog(@"avc cancelled"); //<<<<---
    }
}];
[self presentViewController:avc animated:YES completion:nil];