MFMailComposeViewController *mailComposer;              
mailComposer = [[MFMailComposeViewController alloc]init];
mailComposer.mailComposeDelegate = self;
[mailComposer setSubject:@"My Subject"];        
[mailComposer setMessageBody:@"This is the body of my message" isHTML:NO];      
[self presentModalViewController:mailComposer animated:YES];
[mailComposer release];

UIView *v0 = mailComposer.view;
UIView *v1 = [[v0 subviews] objectAtIndex:0]; // UINavigationTransitionView
UIView *v2 = [[v1 subviews] objectAtIndex:0]; // UIViewControllerWrapperView
UIView *v3 = [[v2 subviews] objectAtIndex:0]; // MFMailComposeView
UIView *v4 = [[v3 subviews] objectAtIndex:0]; // UIView
UIView *v5 = [[v4 subviews] objectAtIndex:0]; // MFComposeScrollView
UIView *v6 = [[v5 subviews] objectAtIndex:0]; // UIView
UIView *v7 = [[v6 subviews] objectAtIndex:0]; // MFMailComposeRecipientView
UIView *v8 = [[v7 subviews] objectAtIndex:1]; // _MFMailRecipientTextField

这个v8家伙就是你想要的人.它是UITextField的子类.让它成为第一响应者.

正式地说,你应该检查子视图的类型而不是第一个或第二个对象.但话说回来,正式你根本不应该这样做,因为这都是无证的,并且可能在未来的iOS版本中破坏.

Undefined symbols for architecture i386:
   "_OBJC_CLASS_ $_MFMailComposeViewController",Referenced from:
       objc-class-ref in ViewController.o
ld: symbol (s) not found for architecture i386
clang: error: linker command Failed with exit code 1 (use-v to see invocation)

请帮忙,这是什么怎么解决？

提前致谢！

以下是您的操作方法：

>在项目导航器侧栏中选择项目.>单击“构建阶段”选项卡.>展开“使用库链接二进制”部分.>点击”按钮.>从列表中选择“MessageUI.framework”. (您可以使用搜索框找到它).

这是我的viewController导航栏颜色：

在定制所有解决方案后,最接近的是：

我的代码中缺少的是什么？请看看.

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

mc.mailComposeDelegate = self;
[mc.navigationBar setTintColor:[UIColor whiteColor]];
[mc setSubject:[Nsstring stringWithFormat:@"V%@ Support",version]];
[mc setMessageBody:supportText isHTML:NO];
[mc setToRecipients:@[@"ring@ringid.com"]];
[self presentViewController:mc animated:YES completion:NULL];

我尝试过：

mc.navigationBar.translucent = NO;
[mc.navigationBar setTintColor:[UIColor myColor]];
mc.navigationBar.backgroundColor = [UIColor myColor];
UIImage *image = [UIImage imageNamed:@"nav-bar_6_plus.png"];
[mc.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];

但没有运气.

提前致谢.

在Swift 3.0中

UINavigationBar.appearance().isTranslucent = false

设置UINavigationBar的外观解决了我的问题.

以下是我一直使用的代码的精确副本：

func launchFeedback() {
    guard MFMailComposeViewController.canSendMail() else {
        return
    }

    let emailTitle = "Feedback"
    let messageBody = ""
    let toRecipents = ["johnappleseed@icloud.com"]
    mailComposer.mailComposeDelegate = self
    mailComposer.setSubject(emailTitle)
    mailComposer.setMessageBody(messageBody,isHTML: false)
    mailComposer.setToRecipients(toRecipents)
    self.show(mailComposer,sender: self)
}

func mailComposeController(controller: MFMailComposeViewController,didFinishWith result: MFMailComposeResult,error: Error?) {
    print(error)
    controller.dismiss(animated: true,completion: nil)
}

@objc(mailComposeController:didFinishWithResult:error:)
    func mailComposeController(_ controller: MFMailComposeViewController,error: NSError?) {
        controller.dismiss(animated: true)
    }

请在方法实现之前查看@objc宏.另请注意,最后一个参数必须是NSError类型而不是Apple文档建议的错误(并由Xcode自动完成)

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

我如何获得此消息的文本？

我需要它用于分析.

日Thnx