用户头像设置之ios版本

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)
        
    }