public void Deactivate()
        {
            if (mTitle)
            {
                tool_bar.Remove(mTitle);
                mTitle.Dispose();
                mTitle = null;
            }

            if (mSlideshowButton)
            {
                tool_bar.Remove(mSlideshowButton);
                mSlideshowButton.Clicked -= OnPushButtonClicked;
                mSlideshowButton.Dispose();
                mSlideshowButton = null;
            }

            if (radiosParent)
            {
                for (int i = 0; i < 3; i++)
                {
                    if (radios[i])
                    {
                        if (0 == i)
                        {
                            radios[0].SelectedChanged -= OnWaveClicked;
                        }
                        if (1 == i)
                        {
                            radios[1].SelectedChanged -= OnCrossClicked;
                        }
                        if (2 == i)
                        {
                            radios[2].SelectedChanged -= OnFoldClicked;
                        }
                        radiosParent.Remove(radios[i]);
                        radios[i].Dispose();
                        radios[i] = null;
                    }
                }
                tool_bar.Remove(radiosParent);
                radiosParent.Dispose();
                radiosParent = null;
            }

            if (tool_bar)
            {
                NUIApplication.GetDefaultWindow().GetDefaultLayer().Remove(tool_bar);
                tool_bar.Dispose();
                tool_bar = null;
            }

            if (mCubeWaveEffect)
            {
                mCubeWaveEffect.TransitionCompleted -= OnCubeEffectCompleted;
                mCubeWaveEffect.Dispose();
                mCubeWaveEffect = null;
            }

            if (mCubeCrossEffect)
            {
                mCubeCrossEffect.TransitionCompleted -= OnCubeEffectCompleted;
                mCubeCrossEffect.Dispose();
                mCubeCrossEffect = null;
            }

            if (mCubeFoldEffect)
            {
                mCubeFoldEffect.TransitionCompleted -= OnCubeEffectCompleted;
                mCubeFoldEffect.Dispose();
                mCubeFoldEffect = null;
            }

            if (mPanGestureDetector)
            {
                mPanGestureDetector.Detected -= OnPanGesture;
                mPanGestureDetector.Dispose();
                mPanGestureDetector = null;
            }

            if (null != mViewTimer)
            {
                mViewTimer.Stop();
                mViewTimer.Tick -= OnTimerTick;
                mViewTimer.Dispose();
                mViewTimer = null;
            }

            if (null != mCurrentEffect)
            {
                mCurrentEffect.StopTransition();
                mContent.Remove(mCurrentEffect);
                mCurrentEffect.Dispose();
                mCurrentEffect = null;
            }

            if (mContent)
            {
                content_layer.Remove(mContent);
                mContent.Dispose();
                mContent = null;
            }

            if (content_layer)
            {
                NUIApplication.GetDefaultWindow().RemoveLayer(content_layer);
                content_layer.Dispose();
                content_layer = null;
            }
        }
        public void Deactivate()
        {
            if (mTitle)
            {
                tool_bar.Remove(mTitle);
                mTitle.Dispose();
                mTitle = null;
            }

            if (mSlideshowButton)
            {
                tool_bar.Remove(mSlideshowButton);
                mSlideshowButton.Clicked -= OnPushButtonClicked;
                mSlideshowButton.Dispose();
                mSlideshowButton = null;
            }

            if (toggle_button)
            {
                tool_bar.Remove(toggle_button);
                toggle_button.Clicked -= OnToggleButtonClicked;
                toggle_button.Dispose();
                toggle_button = null;
            }

            if (tool_bar)
            {
                NUIApplication.GetDefaultWindow().GetDefaultLayer().Remove(tool_bar);
                tool_bar.Dispose();
                tool_bar = null;
            }

            if (mCubeWaveEffect)
            {
                mCubeWaveEffect.TransitionCompleted -= OnCubeEffectCompleted;
                mCubeWaveEffect.Dispose();
                mCubeWaveEffect = null;
            }

            if (mCubeCrossEffect)
            {
                mCubeCrossEffect.TransitionCompleted -= OnCubeEffectCompleted;
                mCubeCrossEffect.Dispose();
                mCubeCrossEffect = null;
            }

            if (mCubeFoldEffect)
            {
                mCubeFoldEffect.TransitionCompleted -= OnCubeEffectCompleted;
                mCubeFoldEffect.Dispose();
                mCubeFoldEffect = null;
            }

            if (mPanGestureDetector)
            {
                mPanGestureDetector.Detected -= OnPanGesture;
                mPanGestureDetector.Dispose();
                mPanGestureDetector = null;
            }

            if (null != mViewTimer)
            {
                mViewTimer.Stop();
                mViewTimer.Tick -= OnTimerTick;
                mViewTimer.Dispose();
                mViewTimer = null;
            }

            if (null != mCurrentEffect)
            {
                mCurrentEffect.StopTransition();
                mContent.Remove(mCurrentEffect);
                mCurrentEffect.Dispose();
                mCurrentEffect = null;
            }

            if (mContent)
            {
                content_layer.Remove(mContent);
                mContent.Dispose();
                mContent = null;
            }

            if (content_layer)
            {
                NUIApplication.GetDefaultWindow().RemoveLayer(content_layer);
                content_layer.Dispose();
                content_layer = null;
            }
        }