iOS 中的 MFMessageComposeController 在哪种情况下会触发 MessageComposeResultFailed？

Question

MFMessageComposeViewController的didFinishWithResult委托方法显示消息已发送成功，即使设备处于飞行模式或设备没有SIM，但消息发送失败。代表没有经历失败 state.Why 它不进入失败状态吗？请给我一些建议。代码如下：

    MFMessageComposeViewController *pic = [[MFMessageComposeViewController alloc] init];
    pic.messageComposeDelegate = self;
    
    // You can specify one or more preconfigured recipients.  The user has
    // the option to remove or add recipients from the message composer view
    // controller.
    /* picker.recipients = @[@"Phone number here"]; */
    
    // You can specify the initial message text that will appear in the message
    // composer view controller.
    pic.body = @"Hello from California!";
    
    [self presentViewController:pic animated:YES completion:NULL];
}

DELEGATE 方法如下：

  // -------------------------------------------------------------------------------
//  messageComposeViewController:didFinishWithResult:
//  Dismisses the message composition interface when users tap Cancel or Send.
//  Proceeds to update the feedback message field with the result of the
//  operation.
// -------------------------------------------------------------------------------
- (void)messageComposeViewController:(MFMessageComposeViewController *)controller 
              didFinishWithResult:(MessageComposeResult)result
{
    
    // Notifies users about errors associated with the interface
    switch (result)
    {
        case MessageComposeResultCancelled:
//Cancelled
            break;
        case MessageComposeResultSent:
//Sent
            break;
        case MessageComposeResultFailed:
//Failed
            break;
        default:
            
            break;
    }
    
    [self dismissViewControllerAnimated:YES completion:NULL];
}

对我来说，当我按下“取消”或“发送”消息时，正确的代表被解雇了。但是当我打开 AIRPLANE 模式或没有 SIM 卡的设备时，MessageComposeResultSent 仍然被触发。有人可以清楚地告诉 MessageComposeResultFailed 什么时候被解雇吗？有活步吗？请帮助我

Answer 1

根据 docs for MessageComposeResult:

这种行为是有意义的

case sent
   The user successfully queued or sent the message.

委托方法可以报告 MessageComposeResultSent 即使您的应用所做的只是将消息交给系统发送。不能保证它确实发送了消息。

文档不清楚它何时报告 MessageComposeResultFailed，但我想它是为了捕获可能发生的任何可能的错误。

根据您的特定用例，您可以在允许某人使用 MFMessageComposeViewController.

之前添加蜂窝连接检查

iOS 中的 MFMessageComposeController 在哪种情况下会触发 MessageComposeResultFailed？

At which case the MessageComposeResultFailed is fired for MFMessageComposeController in iOS?

iphone

xcode

objective-c

ios

mfmessagecomposeview