Cancel and send button missing on MFMailComposeViewController iOS

Question

I am working on an iOS app where user can email and send sms.I am using MFMailComposeViewController & MFMessageComposeViewController for sending email and SMS but sometimes Cancel and Send button appear over composer and sometime it doesn't appear at all. This issue is random and I have tried alot to figure out. Any help will be greatly appreciated. Code

  MFMailComposeViewController *mail = [[MFMailComposeViewController alloc] init];
  mail.mailComposeDelegate = self;
  [mail setSubject:Email_Subject];
  [mail setMessageBody:Share_Message isHTML:NO];
  [mail setToRecipients:@[@""]];
  [self presentViewController:mail animated:YES completion:NULL];

I have implemented MFMailComposeViewControllerDelegate in my viewController in header file.

Answer 1

OK, I've got some traction on this finally. My problem stemmed in part from me changing nav bar colors in my app delegate (Swift):

    UINavigationBar.appearance().barTintColor = UIColor.black
    UIApplication.shared.statusBarStyle = .lightContent

    // To get my hamburger menu white colored
    UINavigationBar.appearance().tintColor = UIColor.white

Due to this, and some interaction with the Zoomed mode (see my comment above), sometimes I'd get the Cancel/Send buttons set to white color in my mail controller. Like this:

I'll show you my class (Objective C) that displays the mail controller, which now works for me to solve the problem in this question. Note that the line:

[UINavigationBar appearance].tintColor = appleBlueTintColor;

is really the secret sauce in all of this:

#import <MessageUI/MessageUI.h>

@interface SendEmail : MFMailComposeViewController

// Returns nil if can't send email on this device. Displays an alert before returning in this case.
- (id) initWithParentViewController: (UIViewController *) parent;

// Show the email composer.
- (void) show;

// Message to append to the bottom of support emails. The string doesn't contain HTML.
+ (NSString *) getVersionDetailsFor: (NSString *) appName;

@end

@interface SendEmail ()<MFMailComposeViewControllerDelegate>
@property (nonatomic, weak) UIViewController *myParent;
@property (nonatomic, strong) UIColor *previousBarTintColor;
@property (nonatomic, strong) UIColor *previousTintColor;
@end

#import "SendEmail.h"
#import <sys/utsname.h>
@implementation SendEmail

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

// Using this init method depends on the `show` method being called immediately after-- to reset the nav bar colors back to what they were originally.
- (id) initWithParentViewController: (UIViewController *) theParent {
    if (![MFMailComposeViewController canSendMail]) {
        NSString *title = @"Sorry, the app isn't allowed to send email.";
        NSString *message = @"Have you configured this device to send email?";
        UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
        [alert addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
        [theParent presentViewController:alert animated:YES completion:nil];
        return nil;
    }

    // The default app nav bar color is black-- and that looks bad on the mail VC. Need to change and then set back both the barTintColor and the tintColor (in the `show` method).

    self.previousBarTintColor = [UINavigationBar appearance].barTintColor;
    self.previousTintColor = [UINavigationBar appearance].tintColor;

    [[UINavigationBar appearance] setBarTintColor:[UIColor whiteColor]];

    // I got this color from the digital color meter-- this is what it is supposed to be on the Cancel/Send buttons.
    UIColor *appleBlueTintColor = [UIColor colorWithRed:31.0/255.0 green:134.0/255.0 blue:254.0/255.0 alpha:1.0];
    [UINavigationBar appearance].tintColor = appleBlueTintColor;

    self = [super init];
    if (self) {
        self.mailComposeDelegate = self;
        self.myParent = theParent;
    }

    return self;
}

- (void) show {
    [self.myParent presentViewController:self animated:YES completion:^{
        [[UINavigationBar appearance] setBarTintColor: self.previousBarTintColor];
        [UINavigationBar appearance].tintColor = self.previousTintColor;
    }];
}

- (void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error {
    [self.myParent dismissViewControllerAnimated:YES completion:nil];
}

+ (NSString *) getVersionDetailsFor: (NSString *) appName;
{
    NSMutableString *message = [NSMutableString string];
    [message appendString:@"\n\n\n--------------\n"];
    [message appendFormat:@"iOS version: %@\n", [[UIDevice currentDevice] systemVersion]];
    [message appendFormat:@"%@ version: %@ (%@)\n", appName,
     [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"],
     [[NSBundle mainBundle]objectForInfoDictionaryKey:@"CFBundleVersion"]];
    [message appendFormat:@"Hardware: %@\n", [self machineName]];

    return message;
}

// See http://stackoverflow.com/questions/11197509/ios-iphone-get-device-model-and-make
+ (NSString *) machineName;
{
    struct utsname systemInfo;
    uname(&systemInfo);

    return [NSString stringWithCString:systemInfo.machine
                              encoding:NSUTF8StringEncoding];
}

@end

Answer 2

My problem was the below line. Just comment this line as it makes the Barbutton title colour Clear.

UIBarButtonItem.appearance().setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor.clear], for: .normal)
//comment this line