当我在发送电子邮件（使用 MFMailComposeViewController）后尝试显示 facebook 共享时，我收到此错误：
一个视图一次最多只能关联一个视图控制器！视图 [EAGLView] 与 [EmailViewController] 相关联。在将此视图与 [FacebookView] 关联之前清除此关联。
[EmailViewController removeFromParentViewController]; 什么也没做
EmailViewController.view = nil; 导致白屏，即使电子邮件表单早已不复存在。
如何让它忘记我曾经发送过电子邮件并让视图层次回到以前的状态？如果我没有发送电子邮件，则 Facebook 共享有效。
-(IBAction)ShowEmailForm:(char*)pSubject :(char*)pBody :(char*)pTo
{
Class mailClass = (NSClassFromString(@"MFMailComposeViewController"));
if (mailClass != nil)
{
if ([mailClass canSendMail])
{
self.view = eaglView;
MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
picker.mailComposeDelegate = self;
[picker setSubject:[NSString stringWithFormat:@"%s", pSubject]];
// Set up recipients
if( pTo != nil )
{
NSArray *toRecipients = [NSArray arrayWithObject:[NSString stringWithFormat:@"%s", pTo]];
[picker setToRecipients:toRecipients];
}
// Fill out the email body text
[picker setMessageBody:[NSString stringWithFormat:@"%s",pBody] isHTML:YES];
[self presentViewController:picker animated:YES completion:^(){}];
[picker release];
}
}
}
// Dismisses the email composition interface when users tap Cancel or Send. Proceeds to update the message field with the result of the operation.
- (void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error
{
[self dismissViewControllerAnimated:YES completion:^(){ printf("Email form done dismissing.\n"); }];
printf("Email form dismissed.\n");
[self removeFromParentViewController];
//Email was sent.
if (result == MFMailComposeResultSent)
{
printf("Email Sent!\n");
NSString *pEmail = [self findEmailAddresses:controller.view : 0];
}
}