MFMailComposer crashes

In my app I am using MFMailComposer. It crashes when I send mail without mail configuration (without having entered mail ID and password in the Mail app on the device).

This is the line that causes the crash:开发者_如何转开发

[self presentModalViewController:picker animated:YES];

-(void) showEmailModalView
{
    NSLog(@"Start method <ExportStatisticsController> : <showEmailModalView>  --");


    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate = self; // &lt;- very important step if you want feedbacks on what the 
    //user did with your email sheet

    [picker setSubject:SendEmailSubject];

    NSArray *torec=[[NSArray alloc] initWithObjects:SendEmailToEmailID, nil];
    [picker setToRecipients:torec];
    [torec release];

    //------ message body ---

    NSString *body =@"";
    body=[NSString stringWithFormat:@"%@ From : %@\n",body, emailTextField.text];
    body=[NSString stringWithFormat:@"%@ Subject : %@\n",body,subjectTextField.text];



    //email contents
    body = [NSString stringWithFormat:@"%@ Message : \n  %@", body,messageBodyTextView.text];


    [picker setMessageBody:body isHTML:NO]; // depends. Mostly YES, unless you want to send it as plain text (boring)

    picker.navigationBar.barStyle = UIBarStyleBlack; // choose your style, unfortunately, Translucent colors behave quirky.

    [self presentModalViewController:picker animated:YES];
    [picker release];
    NSLog(@"End method <ExportStatisticsController> : <showEmailModalView>  --");

}

// 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
{ 
    NSLog(@"Start method <ExportStatisticsController> : <didFinishWithResult>  --");
    // Notifies users about errors associated with the interface
    switch (result)
    {
        case MFMailComposeResultCancelled:
            NSLog(@"Message MFMailComposeResultCancelled");
            break;
        case MFMailComposeResultSaved:
            NSLog(@"Message MFMailComposeResultSaved");
            break;
        case MFMailComposeResultSent:
            NSLog(@"Message sent Successfuly");

            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Email" message:@"Mail Sent Successfully!"
                                                           delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
            [alert show];
            [alert release];

            break;
        case MFMailComposeResultFailed:
            NSLog(@"Message MFMailComposeResultFailed");
            break;

        default:
        {
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Email" message:@"Sending Failed - Unknown Error :-("
                                                           delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
            [alert show];
            [alert release];
        }

            break;
    }
    [self dismissModalViewControllerAnimated:YES];
    NSLog(@"End method <ExportStatisticsController> : <didFinishWithResult>  --");
}

You should call

[MFMailComposeViewController canSendMail]

before presenting the view controller, eg

if ([MFMailComposeViewController canSendMail]) {
    MFMailComposeViewController *composer = [[MFMailComposeViewController alloc] init];
    [self presentModalViewController:composer];
} else {
    // Show error message maybe
}

That's true. You will have to configure your mail app and check whether the device can send mail or not. Since if it would have been possible without mail app then we would be able to send mail via simulator (which I think is not possible). The receiver of your mail must know from where he/she is getting the mail and I think the sender cannot be set from the code I might be wrong but these are my view since I was struggling the same situation.

Hope it helps.