MFMailComposeViewController throws an error only in iOS 9

Question

I can't get MFMailComposeViewController to open without throwing a fatal error in iOS 9 Simulator.

The same code (Objective C) works flawlessly in iOS 8.x and lower but today I installed Xcode 7 beta 5 and when I run the app on iOS 9 Simulator, I get a dialog box titled "MailCompositionService quit unexpectedly" and when I view the error report, I see:

Application Specific Information: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayI isEqualToString:]: unrecognized selector sent to instance 0x7fd314280b10'

terminating with uncaught exception of type NSException abort() called CoreSimulator 179 - Device: iPhone 6 - Runtime: iOS 9.0 (13A4325c) - DeviceType: iPhone 6

The error happens when the mail composition view comes up. It freezes for a few seconds and then the error dialog box comes up.

The code that opens the mail composition view is:

if ([MFMailComposeViewController canSendMail])
{
    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate = self;
    [picker setSubject:@"Comment title"];
    [picker setMessageBody:@"Comment description" isHTML:NO];

    [self.window.rootViewController presentModalViewController:picker animated:YES];
    [picker release];
}

If it helps to know, before the app crashes, mailComposeController:didFinishWithResult:error: is called with result = MFMailComposeResultCancelled and error = nil.

I'd appreciate tips on how to find the cause of this error. Thanks!

Answer 1

The issue is with simulator, on the real device mail composer is working correctly.

Answer 2

As per Apple Developer Forum, more details are here.

The simulator doesn't support mail. You should likely try testing mail functionality in a device.

Answer 3

You should use : [self.window.rootViewController presentViewController:picker animated:YES completion:NULL]; presentModalViewController is DEPRECATED since ios6 is and has been replaced by presentViewController:animated:completion: ie: - (void)presentModalViewController:(UIViewController *)modalViewController animated:(BOOL)animated NS_DEPRECATED_IOS(2_0, 6_0);

Answer 4

I have no idea why it happens or how did I discovered it, the crash seems to be generated by setting the NSFontAttributeName in the Appearance proxy for the navigation bar, if I uncomment that line the app crashes.

    NSDictionary* format = @{
                         NSForegroundColorAttributeName:[UIColor whiteColor],
                         //NSFontAttributeName: [UIFont boldSystemFontOfSize:20],
                         };

[[UINavigationBar appearance] setTitleTextAttributes:format];

Please @Sleiman try and see if this fixes the issue for you too.

Answer 5

As a simple work around for this problem, you can use "mailto" protocol, it will:

• Not crash the app (device and simulator)
• Prompt the user to login if the device has not login with any mail account

Example in swift:

Swift 3.0

let mailRecipient = "support@abc.com"
let mailSubject = "Help with ABC for iOS"
let mailBody = "xxx"

let mailTo = "mailto:\(mailRecipient)?subject=\(mailSubject)&body=\(mailBody)"

guard let escapedMailTo = mailTo.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) else {
    NSLog("Invalid mail to format")
    return
}

guard let url = NSURL(string: escapedMailTo) else {
    NSLog("Invalid mail to format: \(escapedMailTo)")
    return
}

UIApplication.sharedApplication().openURL(url)

Swift 2.3

let mailRecipient = "support@abc.com"
let mailSubject = "Help with ABC for iOS"
let mailBody = "xxx"

let mailTo = "mailto:\(mailRecipient)?subject=\(mailSubject)&body=\(mailBody)"

guard let escapedMailTo = mailTo.stringByAddingPercentEncodingWithAllowedCharacters(.URLQueryAllowedCharacterSet()) else {
    NSLog("Invalid mail to format")
    return
}

guard let url = NSURL(string: escapedMailTo) else {
    NSLog("Invalid mail to format: \(escapedMailTo)")
    return
}

UIApplication.sharedApplication().openURL(url)