Windows Phoneでシャッターボタンの押下イベントを受信する

ハードウェアのカメラボタンの押下イベントを拾います。それぞれのイベントにイベントハンドラを指定してください。

    // The event is fired when the shutter button receives a half press.
    CameraButtons.ShutterKeyHalfPressed += OnButtonHalfPress;

    // The event is fired when the shutter button receives a full press.
    CameraButtons.ShutterKeyPressed += OnButtonFullPress;

    // The event is fired when the shutter button is released.
    CameraButtons.ShutterKeyReleased += OnButtonRelease;

シャッターボタンの半押しを検知する

        // Provide auto-focus with a half button press using the hardware shutter button.
        private void OnButtonHalfPress(object sender, EventArgs e)
        {
            if (cam != null)
            {
                // Focus when a capture is not in progress.
                try
                {
                    this.Dispatcher.BeginInvoke(delegate()
                    {
                        txtDebug.Text = "Half Button Press: Auto Focus";
                    });

                    cam.Focus();
                }
                catch (Exception focusError)
                {
                    // Cannot focus when a capture is in progress.
                    this.Dispatcher.BeginInvoke(delegate()
                    {
                        txtDebug.Text = focusError.Message;
                    });
                }
            }
        }

シャッターボタンが押されたのを検知する

        // Capture the image with a full button press using the hardware shutter button.
        private void OnButtonFullPress(object sender, EventArgs e)
        {
            if (cam != null)
            {
                cam.CaptureImage();
            }
        }

シャッターボタンが離されたのを検知する

        // Cancel the focus if the half button press is released using the hardware shutter button.
        private void OnButtonRelease(object sender, EventArgs e)
        {

            if (cam != null)
            {
                cam.CancelFocus();
            }
        }