MonoTouch-iOS使用UIImagePickerController打开图片库和相机选择图片修改头像

 //圆角头像 _avatarView = new UIImageView(new RectangleF(_blockSpace, _blockSpace, 2 * _avatarRadius, 2 * _avatarRadius));UIImage img = UIImage.FromFile("profile-pic.jpg");_avatarView.Layer.Contents = img.CGImage;_avatarView.Layer.MasksToBounds = true;//如果没有将MasksToBounds设置为true，图片圆角无效_avatarView.Layer.CornerRadius = _avatarRadius; _avatarView.UserInteractionEnabled = true;//用户互动属性()_avatarView.AddGestureRecognizer(new UITapGestureRecognizer(onClickImage));

 void onClickImage() {            try            {                //UIActionSheet是在iOS弹出的选择按钮项的对话框，可以添加多项，并为每项添加点击事件。                //ChangePictureActionSheetDelegate：通过重写UIActionSheetDelegate的Clicked方法，获取当前点击项                UIActionSheet _actionSheet = new UIActionSheet("选择图片",                new ChangePictureActionSheetDelegate(this,_avatarView), "取消",                null, "从相片库", "拍照");                                _actionSheet.ShowInView(this.View);            }            catch (Exception e)            {                Console.WriteLine("Error:" + e.Message);            } }

class ChangePictureActionSheetDelegate : UIActionSheetDelegate    {        UIViewController _controller;        UIImageView _img;        UIImagePickerController picker;        public ChangePictureActionSheetDelegate(UIViewController controller,UIImageView img)        {            _controller = controller;            _img = img;        }        public override void Clicked(UIActionSheet actionSheet, int buttonIndex)        {            Console.WriteLine("你选择了：" + buttonIndex);            switch (buttonIndex)            {                case 1: CallPhoto(UIImagePickerControllerSourceType.Camera); break;                case 0: CallPhoto(UIImagePickerControllerSourceType.PhotoLibrary); break;                default: break;            }        }                        private void CallPhoto(UIImagePickerControllerSourceType type)        {            Console.WriteLine("Begin...");            if (UIImagePickerController.IsSourceTypeAvailable(type))            {                try                {                    picker = new UIImagePickerController();                    picker.SourceType = type;                    //允许编辑图片                    picker.AllowsEditing = true;                    if (_controller.PresentedViewController == null)                    {                        _controller.PresentModalViewController(picker, false);                    }                    //picker.FinishedPickingImage += picker_FinishedPickingImage;(无效)                    //AvatarPickerDelegate：通过重写UIImagePickerControllerDelegate的FinishedPickingImage方法获取选择的图片                    picker.Delegate =new AvatarPickerDelegate(_img);                    Console.WriteLine("Finished");                }                catch (Exception e)                {                    Console.WriteLine("Error:" + e.Message);                }            }            else            {                Console.WriteLine("该设备不支持此操作");            }        }    }

class AvatarPickerDelegate:UIImagePickerControllerDelegate {        UIImageView _avatar;        public AvatarPickerDelegate(UIImageView _imgView) {            _avatar = _imgView;        }                public override void FinishedPickingImage(UIImagePickerController picker, UIImage image, NSDictionary editingInfo)        {            Console.WriteLine("选择了图片");            if (image == null)            {                Console.WriteLine("Null");            }           //更新显示图片            _avatar.Layer.Contents = image.CGImage;            //关闭UIImagePicker            picker.DismissModalViewControllerAnimated(true);            Console.WriteLine("完成选择");                    }    }