Application tried to present a nil modal view controller on target in iOS 10?

Question

I am implementing MFMailComposeViewController in my application when I click on my mail button I am get the below error.

Application tried to present a nil modal view controller on target strong text

Here's my code:

    NSString *iOSVersion = [[UIDevice currentDevice] systemVersion];
    NSString * version = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"];

    NSString * build = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleVersion"];

    mailComposer = [[MFMailComposeViewController alloc]init];
    mailComposer.navigationBar.tintColor = [UIColor blackColor];
    [mailComposer.navigationBar setTitleTextAttributes:
     @{NSForegroundColorAttributeName:[UIColor blackColor]}];
    mailComposer.mailComposeDelegate = self;

    [mailComposer setSubject:@"Co - Contact Us"];

    [mailComposer setToRecipients:@[@"contact@co.org"]];
    NSString *supportText = @"Enter your comment here:\n\n\n\n\n";
    supportText = [supportText stringByAppendingString:[NSString stringWithFormat:@"iOS Version: %@\nCorner Version:%@\nBuild:%@\n\n",iOSVersion,version, build]];
    [mailComposer setMessageBody:supportText isHTML:NO];

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

What's wrong with my code. Please help

Answer 1

If device has not configured mail or using simulator can lead to crash or exception.

mailComposer = [[MFMailComposeViewController alloc] init];

above line of code can cause problem. in simulator initializer method may return NULL or nil.

so, just check for canSendMail before presenting modal viewController:

Like,

    NSString *iOSVersion = [[UIDevice currentDevice] systemVersion];
    NSString * version = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"];

    NSString * build = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleVersion"];

    mailComposer = [[MFMailComposeViewController alloc]init];

    if ([MFMailComposeViewController canSendMail] && mailComposer) {

       mailComposer.navigationBar.tintColor = [UIColor blackColor];
       [mailComposer.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor blackColor]}];
       mailComposer.mailComposeDelegate = self;

       [mailComposer setSubject:@"Corner - Contact Us"];

       [mailComposer setToRecipients:@[@"contact@corner.org"]];
       NSString *supportText = @"Enter your comment here:\n\n\n\n\n";
       supportText = [supportText stringByAppendingString:[NSString stringWithFormat:@"iOS Version: %@\nCorner Version:%@\nBuild:%@\n\n",iOSVersion,version, build]];
       [mailComposer setMessageBody:supportText isHTML:NO];

      [self presentViewController:mailComposer animated:YES completion:nil];
}