Question

我希望能够从我的应用发送一封电子邮件，其中我已经完成了该部分工作。问题是当我取消发送电子邮件时（这是我现在正在测试的）电子邮件部分被解雇但我留下了黑屏，我似乎无法解雇。

所以这就是我所拥有的。我已经创建了一个类来处理电子邮件部分：

MailViewController.h

#import <UIKit/UIKit.h>
#import <MessageUI/MessageUI.h>

@interface MailViewController : UIViewController <MFMailComposeViewControllerDelegate>


@end

实施如下：

#import "MailViewController.h"

@interface MailViewController ()

@end

@implementation MailViewController

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

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    if([MFMailComposeViewController canSendMail]){
        MFMailComposeViewController *mailer = [[MFMailComposeViewController alloc] init];
        [mailer setMailComposeDelegate:self];

        [mailer setSubject:@"Subject"];
        NSMutableArray *toArray = [[NSMutableArray alloc] initWithObjects:@"email@gmail.com", nil];
        [mailer setToRecipients:toArray];

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

    }
    else{
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Failuer" message:@"This device is unable to send emails" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
        [alert show];
    }
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


-(void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error{

    switch (result){
        case MFMailComposeResultCancelled:
            NSLog(@"Mail cancelled: you cancelled the operation and no email was sent");
            break;

        case MFMailComposeResultFailed:
            NSLog(@"Mail failed");
            break;

        case MFMailComposeResultSaved:
            NSLog(@"Mail saved");
            break;

        case MFMailComposeResultSent:
            NSLog(@"Mail sent");
            break;

        default:
            NSLog(@"Mail not sent");
            break;
    }

    [controller dismissViewControllerAnimated:YES completion:nil];
}


@end

所有这些都从另一个视图中显示出来：

-(IBAction)sendMessage:(id)sender{
    NSLog(@"Going to send an email....");

    MailViewController *mail = [[MailViewController alloc] init];

    [self.navigationController pushViewController:mail animated:YES];


}

因此，当我运行所有这些时，电子邮件程序会打开，我可以发送电子邮件。我可以选择取消，然后删除草稿，删除电子邮件程序。但是，我留下了黑屏，然后我可以从顶部导航栏中选择返回以返回上一个视图。

我只是希望应用程序返回到显示电子邮件程序时发送或取消（或其他）电子邮件程序的视图。我确信这很简单，我很遗憾。

Answer 1

问题是你是pushing一个MailViewController然后是dimissing，如果你push你应该pop视图控制器。

MFMailComposeViewController应以模态方式呈现，而不是推送到导航堆栈上。您也不需要子类，您可以直接创建MFMailComposeViewController的实例：

-(IBAction)sendMessage:(id)sender{
    NSLog(@"Going to send an email....");

    MFMailComposeViewController *mail = [[MFMailComposeViewController alloc] init];
    mail.mailComposeDelegate = self;
    [self presentViewController:mail animated:YES completion:nil];
}

-(void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error{

    switch (result){
        case MFMailComposeResultCancelled:
            NSLog(@"Mail cancelled: you cancelled the operation and no email was sent");
            break;

        case MFMailComposeResultFailed:
            NSLog(@"Mail failed");
            break;

        case MFMailComposeResultSaved:
            NSLog(@"Mail saved");
            break;

        case MFMailComposeResultSent:
            NSLog(@"Mail sent");
            break;

        default:
            NSLog(@"Mail not sent");
            break;
    }

    [controller dismissViewControllerAnimated:YES completion:nil];
}

Answer 2

我有几个架构问题，但首先是TL; DR版本：

[self.navigationController popViewControllerAnimated:NO];

您也可以为布尔值选择YES，但是根据您的实现来判断，这不会产生好的结果。把它放在代表电话中完成。

然而，为什么不把任何推动MailViewController推入堆栈处理作为MFMailComposeViewControllerDelegate的工作呢？你在这里什么都不做，需要一个全新的视图控制器被推入堆栈。

取消电子邮件后关闭视图

2 个答案: