iphone - 应用程序试图在目标上呈现一个 nil 模态视图控制器

Question

我收到以下错误：

Application tried to present a nil modal view controller on target <UINavigationController: 0x2007af00>.

在以下代码上：

-(void) showAddressBookDialog
{
    [self presentMailComposeViewController:nil];
}


- (void)presentMailComposeViewController:(NSString *)recipient {
    // Create the compose email view controller
    MFMailComposeViewController *composeEmailViewController = [[MFMailComposeViewController alloc] init];
    [composeEmailViewController setMailComposeDelegate:self];
    [composeEmailViewController setSubject:@"Join me on X"];
    [composeEmailViewController setToRecipients:[NSArray arrayWithObjects:recipient, nil]];
    [composeEmailViewController setMessageBody:@"" isHTML:YES];
    [composeEmailViewController setModalPresentationStyle:UIModalPresentationFormSheet];
    [self dismissModalViewControllerAnimated:NO];
    self.inviteFriendsMailComposerVC_ = composeEmailViewController;
    //[self.navigationController presentModalViewController:composeEmailViewController animated:YES];
    [self.navigationController presentViewController:composeEmailViewController animated:YES completion:nil];
    [composeEmailViewController release];
}

知道为什么吗？

Answer 1

我想知道你为什么要先解雇你的观点......从你的方法中删除这一行

[self dismissModalViewControllerAnimated:NO];

最好先检查设备是否配置为发送电子邮件。看到这个链接

Answer 2

navigationController是 all 的属性，UIViewControllers它为您提供其父导航视图控制器（如果存在）。听起来您从未添加 yourviewController到导航控制器的视图控制器堆栈中。