1.实现这些Delegate，UIActionSheetDelegate,UIImagePickerControllerDelegate, UINavigationControllerDelegate 2.为了方便测试添加两个控件            var btnChoose = UIButton(frame: CGRect(x: 20, y: 40, width: 100, height: 50))                btnChoose.setTitle("设置照片", forState: UIControlState.Normal)        btnChoose.backgroundColor = UIColor.grayColor()                btnChoose.addTarget(self, action: "chooseImgAction", forControlEvents: UIControlEvents.TouchUpInside)                self.view.addSubview(btnChoose)                                imgShow = UIImageView(frame: CGRect(x: 20, y: 120, width: 100, height: 100))                imgShow.backgroundColor = UIColor.grayColor()        self.view.addSubview(imgShow)                 3.实现各种点击事件和弹出框       func chooseImgAction() {                        var sheet:UIActionSheet                if(UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera))        {            sheet = UIActionSheet(title: "选择头像", delegate: self, cancelButtonTitle: "取消", destructiveButtonTitle: nil, otherButtonTitles: "从相册选择","拍照")        }else                    {            sheet = UIActionSheet(title:"选择头像", delegate: self, cancelButtonTitle: "取消", destructiveButtonTitle: nil, otherButtonTitles: "从相册选择")        }                        sheet.showInView(self.view)    }            func actionSheet(actionSheet: UIActionSheet, clickedButtonAtIndex buttonIndex: Int)    {        var sourceType = UIImagePickerControllerSourceType.PhotoLibrary        if(buttonIndex != 0)        {            if(buttonIndex==1)            {                //相册                sourceType = UIImagePickerControllerSourceType.PhotoLibrary            }else{                sourceType = UIImagePickerControllerSourceType.Camera            }            let imagePickerController:UIImagePickerController = UIImagePickerController()            imagePickerController.delegate = self            imagePickerController.allowsEditing = true//true为拍照、选择完进入图片编辑模式            imagePickerController.sourceType = sourceType            self.presentViewController(imagePickerController, animated: true, completion:                {            })        }    }                  func imagePickerControllerDidCancel(picker:UIImagePickerController)      {        self.dismissViewControllerAnimated(true, completion: nil)    }            func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage!, editingInfo: [NSObject : AnyObject]!) {          imgShow.image = image        self.dismissViewControllerAnimated(true, completion: nil)            }