我想使用 
 swift来实现应用内电子邮件.当我点击按钮时,会弹出电子邮件窗口.但是,我无法发送电子邮件.此外,点击取消删除草稿后,我无法返回到原始屏幕. 
  
  
 
import UIkit
import MessageUI
class information : UIViewController,MFMailComposeViewControllerDelegate{
    var myMail: MFMailComposeViewController!
    @IBAction func sendReport(sender : AnyObject) {
        if(MFMailComposeViewController.canSendMail()){
            myMail = MFMailComposeViewController()
            //myMail.mailComposeDelegate
            // set the subject
            myMail.setSubject("My report")
            //To recipients
            var toRecipients = ["lipeilin@gatech.edu"]
            myMail.setToRecipients(toRecipients)
            //CC recipients
            var ccRecipients = ["tzhang85@gatech.edu"]
            myMail.setCcRecipients(ccRecipients)
            //CC recipients
            var bccRecipients = ["tzhang85@gatech.edu"]
            myMail.setBccRecipients(ccRecipients)
            //Add some text to the message body
            var sentfrom = "Email sent from my app"
            myMail.setMessageBody(sentfrom,isHTML: true)
            //Include an attachment
            var image = UIImage(named: "Gimme.png")
            var imageData = UIImageJPEGRepresentation(image,1.0)
            myMail.addAttachmentData(imageData,mimeType: "image/jped",fileName:     "image")
            //display the view controller
            self.presentViewController(myMail,animated: true,completion: nil)
        }
        else{
            var alert = UIAlertController(title: "Alert",message: "Your device cannot send emails",preferredStyle: UIAlertControllerStyle.Alert)
            alert.addAction(UIAlertAction(title: "OK",style: UIAlertActionStyle.Default,handler: nil))
            self.presentViewController(alert,completion: nil)
        }
    }
func mailComposeController(controller: MFMailComposeViewController!,didFinishWithResult result: MFMailComposeResult,error: NSError!){
        switch(result.value){
        case MFMailComposeResultSent.value:
            println("Email sent")
        default:
            println("Whoops")
        }
        self.dismissViewControllerAnimated(true,completion: nil)
}
}
解决方法
 由于您尚未将当前视图控制器设置为myMail的mailComposeDelegate,因此未调用mailComposeController:didFinishWithResult方法.初始化myMail后,请确保添加: 
  
  
 
        myMail.mailComposeDelegate = self
你会很好的去