Question

I have a simple app, which opens a modal view to send email. Am using Xcode 4.2 and iOS 5, and am testing with iOS Simulator. The app crashes with
Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason:
‘Application tried to present a nil modal view controller on target
.’

when executing the line:

 [self presentModalViewController:mailComposer animated:YES];

though I have initialized the object ‘mailComposer’.

Class com_FirstViewController.m :

#import "com_FirstViewController.h"
...
@implementation com_FirstViewController
....
....
-(void)showEmailComposer {

Class mailClass = (NSClassFromString(@"MFMailComposeViewController"));
if (mailClass != nil)
{
    if ([mailClass canSendMail]) {
                    NSLog(@"showEmailComposer: Calling displayComposerSheet");
        [self displayComposerSheet];

    } else {
                    NSLog(@"showEmailComposer: Calling launchMailAppOnDevice");
        [self launchMailAppOnDevice];
    }
}
else {
            NSLog(@"showEmailComposer: Calling launchMailAppOnDevice");
    [self launchMailAppOnDevice];
}
}



#pragma mark -
#pragma mark Compose Mail

-(void) displayComposerSheet {

    mailComposer = [[MFMessageComposeViewController alloc] init];
    mailComposer.messageComposeDelegate = self;

    // Set the mail title
    [mailComposer setTitle:@"Mail Title"];

    // Set the recipients
    NSArray *toRecipients = [NSArray arrayWithObject:@"[e-mail]"];

    [mailComposer setRecipients:toRecipients];

    // EMail Body
    NSString *mailBody = @"This is the mail body";
    [mailComposer setBody:mailBody];

    NSLog(@"present the modal view ctlr");
    [self presentModalViewController:mailComposer animated:YES];
}
...
...

Any pointers please?

Answer 1

 mailComposer = [[MFMessageComposeViewController alloc] init];

is the source of the problem, in my opinion. There’s no way the simulator can send SMS messages, so the initializer method may return NULL. Anyways, sou seem to be wanting to send an email, so I’d say you need to use

 mailComposer = [[MFMailComposeViewController alloc] init];