应用程序在IOS7中的MFMailComposeViewController对象上崩溃

Question

我正在创造

MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];

但由于未捕获的异常'NSInvalidArgumentException',应用程序因错误终止应用程序而导致应用程序崩溃且应用程序崩溃,原因:'Application tried to present a nil modal view controller on target.它在模拟器中工作正常,但在Device中崩溃.如何使用MFMailComposerViewControllerIOS 7.

Answer 1

您应该检查MFMailComposeViewController是否能够在尝试发送之前发送您的邮件(例如,用户在iOS设备上没有任何邮件帐户).

在您的Objective-C案例中:

MFMailComposeViewController *myMailCompose = [[MFMailComposeViewController alloc] init];

if ([MFMailComposeViewController canSendMail]) {
    myMailCompose.mailComposeDelegate = self;
    [myMailCompose setSubject:@"Subject"];
    [myMailCompose setMessageBody:@"message" isHTML:NO];
    [self presentViewController:myMailCompose animated:YES completion:nil];
} else {
    // unable to send mail, notify your users somehow
}

斯威夫特3:

let myMailCompose = MFMailComposeViewController()

if MFMailComposeViewController.canSendMail() {
    myMailCompose.mailComposeDelegate = self
    myMailCompose.setSubject("Subject")
    myMailCompose.setMessageBody("message", isHTML: false)
    self.present(myMailCompose, animated: true, completion: nil)
} else {
    // unable to send mail, notify your users somehow
}