问不能用UIActivityViewController发图片到新浪微博

EN

- (IBAction)shareButtonPressed:(id)sender
{
    NSString *shareString = @"Check this out!";
    UIImage *shareImage = [self captureView:self.view];

    NSArray *activityItems = [NSArray arrayWithObjects:shareString, shareImage, nil];

    UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];
    activityViewController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

    activityViewController.excludedActivityTypes = @[UIActivityTypePrint, UIActivityTypeCopyToPasteboard, UIActivityTypeAssignToContact, UIActivityTypeSaveToCameraRoll, UIActivityTypeAddToReadingList, UIActivityTypeAirDrop];

    [self presentViewController:activityViewController animated:YES completion:nil];

- (UIImage*)captureView
{
    CGRect screenRect = [[UIScreen mainScreen] bounds];
    UIGraphicsBeginImageContextWithOptions(screenRect.size, NO, 0.0);
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}