所以这是我的问题，我在 twitter 和 Facebook 中添加了一个操作表，它工作正常，但是当我在电子邮件编辑器中添加时，应用程序似乎无法返回原始屏幕并停留在电子邮件编辑器中。
- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex {
//Each button title we gave to our action sheet is given a tag starting with 0.
if (buttonIndex == 0) {
//Check Twitter accessibility and at least one account is setup.
if([SLComposeViewController isAvailableForServiceType:SLServiceTypeTwitter]) {
SLComposeViewController *tweetSheet =[SLComposeViewController composeViewControllerForServiceType:SLServiceTypeTwitter];
//This is setting the initial text for our share card.
[tweetSheet setInitialText:@"Switcher makes social networking easier, download it now from (LINK):D "];
//Brings up the little share card with the test we have pre defind.
[self presentViewController:tweetSheet animated:YES completion:nil];
} else {
//This alreat tells the user that they can't use built in socal interegration and why they can't.
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Sorry" message:@"You can't send a tweet right now, make sure you have logged into twitter aleady from your iphone settings." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alertView show];
}
}else if (buttonIndex == 1) {
//Check Facebook accessibility and at least one account is setup.
if([SLComposeViewController isAvailableForServiceType:SLServiceTypeFacebook]) {
SLComposeViewController *facebookSheet =[SLComposeViewController composeViewControllerForServiceType:SLServiceTypeFacebook];
//This is setting the initial text for our share card.
[facebookSheet setInitialText:@"Switcher makes social networking easier, download it now from (LINK) :D "];
//Brings up the little share card with the test we have pre defind.
[self presentViewController:facebookSheet animated:YES completion:nil];
} else {
//This alreat tells the user that they can't use built in socal interegration and why they can't.
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Sorry" message:@"You can't send a post right now, make sure you have logged into facebook aleady from your iphone settings" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alertView show];
}
}else if (buttonIndex == 2) {
MFMailComposeViewController *mailContoller = [[MFMailComposeViewController alloc]init];
[mailContoller setMailComposeDelegate:self];
NSString *email = @"";
NSArray *emailArray = [[NSArray alloc]initWithObjects:email,nil];
NSString *message = @"hey download my application now";
[mailContoller setMessageBody:message isHTML:NO];
[mailContoller setToRecipients:emailArray];
[mailContoller setSubject:@""];
[self presentViewController:mailContoller animated:YES completion:nil];
}