初始化时 PhotoCamera 问题 [英] PhotoCamera issue while Initialization

问题描述

我正在开发使用 PhotoCamera 捕捉图像的 windows phone 8 应用程序.按屏幕锁定键时出现问题.当我按下锁定键时，我的 PhotoCamera 对象没有处理.我在相机初始化时按屏幕锁定键时出现问题.

I am developing windows phone 8 app which use PhotoCamera for capturing image. I am getting issue when I press screen lock key. My PhotoCamera object not disposing when I press lock key. I am getting the problem when I press screen lock key at the time of Camera Initialization.

这是一些代码.

按钮点击代码

_photoCamera = new PhotoCamera();
_photoCamera.Initialized += OnPhotoCameraInitialized;
_photoCamera.CaptureImageAvailable += new EventHandler<Microsoft.Devices.ContentReadyEventArgs>(cam_CaptureImageAvailable);
_photoCamera.AutoFocusCompleted += new EventHandler<CameraOperationCompletedEventArgs>(cam_AutoFocusCompleted);

_previewTransform.Rotation = _photoCamera.Orientation;
_previewVideo.SetSource(_photoCamera);

这是我的OnPhotoCameraInitialized代码

 private void OnPhotoCameraInitialized(object sender, CameraOperationCompletedEventArgs e)
 {
        try
        {
            Dispatcher.BeginInvoke(() =>
            {
                gvCamera.Visibility = Visibility.Visible;
                gvCameraImage.Visibility = Visibility.Collapsed;
                Cancel.Visibility = Visibility.Visible;
                imgScanCancle.Visibility = Visibility.Visible;
            });
            cameraInit = true;
            _photoCamera.FlashMode = FlashMode.Auto;
            _photoCamera.Focus();
        }
        catch (Exception ex)
        {
            //MessageBox.Show(ex.Message);
        }
 }

这是我的NavigationFrom代码

protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
{
        base.OnNavigatedFrom(e);
        try
        {
            if (cameraInit)
            {
                if (_photoCamera != null)
                {
                    _photoCamera.Dispose();
                    _photoCamera.Initialized -= OnPhotoCameraInitialized;
                    _photoCamera.CaptureImageAvailable -= cam_CaptureImageAvailable;
                    _photoCamera.AutoFocusCompleted -= cam_AutoFocusCompleted;
                    _photoCamera = null;
                    cameraInit = false;
                }
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
 }

我在 OnNavigatedTo 方法中重新初始化了相机

I have re-Initialized photocamera in OnNavigatedTo Method

这是OnNavigatedTo 代码.

            if (GlobalSettings.IspreservedState)
            {
                if (!GlobalSettings.istest_performed)
                {                        
                    if (_photoCamera == null)
                    {
                        _nbTry = 0;

                        _photoCamera = new PhotoCamera();
                        _photoCamera.Initialized += OnPhotoCameraInitialized;
                        _photoCamera.CaptureImageAvailable += new EventHandler<Microsoft.Devices.ContentReadyEventArgs>(cam_CaptureImageAvailable);
                        _photoCamera.AutoFocusCompleted += new EventHandler<CameraOperationCompletedEventArgs>(cam_AutoFocusCompleted);

                        _previewTransform.Rotation = _photoCamera.Orientation;
                        _previewVideo.SetSource(_photoCamera);
                    }
                }
            }

基本上我想做的是捕获图片并显示它.在相机初始化之前按下锁定键时出现问题.当我按下锁定键时，OnNavigatedFrom 代码开始执行.当它到达 if(cameraInit) 内部代码时不会执行，因为 cameraInit 不正确.我在 OnPhotoCameraInitialized 方法中设置了 cameraInit = true;.但不幸的是这个代码块没有执行.所以我的问题是如何处理相机对象?我只能在它完全初始化时处理它.但是我在 Initialization 之前按了锁定键.有没有办法清理视频刷?

Basically what I am trying to do is Capture the picture and display it. I have a problem when I press a lock key before camera Initialization. When I press lock key, OnNavigatedFrom code start executing. When it reach to if(cameraInit) inside code not executed because cameraInit not true. I have set cameraInit = true; in OnPhotoCameraInitialized method. But unfortunately this code block not execute. so my question is How can I dispose camera object? I can dispose it only when it is fully Initialized. But I press lock key before Initialization. Is there any way to clean the video brush?

推荐答案

大家好，我的问题都解决了.

Hello to all my problem is solved.

我更改了 OnNavigatedFrom 和 OnPhotoCameraInitialized 中的代码.

I have changed code in OnNavigatedFrom and OnPhotoCameraInitialized.

这是代码OnNavigatedFrom

            if (cameraInit)
            {
                Dispatcher.BeginInvoke(() =>
                {
                    if (_photoCamera != null)
                    {
                        _photoCamera.Dispose();
                        _photoCamera.Initialized -= OnPhotoCameraInitialized;
                        _photoCamera.CaptureImageAvailable -= cam_CaptureImageAvailable;
                        _photoCamera.AutoFocusCompleted -= cam_AutoFocusCompleted;
                        _photoCamera = null;
                        cameraInit = false;
                    }
                });
            }

这是我的 OnPhotoCameraInitialized

            if (e.Succeeded)
            {
                cameraInit = true;

                Dispatcher.BeginInvoke(() =>
                {
                    gvCamera.Visibility = Visibility.Visible;
                    gvCameraImage.Visibility = Visibility.Collapsed;
                    Cancel.Visibility = Visibility.Visible;
                    imgScanCancle.Visibility = Visibility.Visible;

                    if (cameraInit)
                    {
                        _photoCamera.FlashMode = FlashMode.Auto;
                        _photoCamera.Focus();
                    }
                });
            }

这里当我在初始化之前按下屏幕锁定键时，我做的第一件事就是完全初始化相机，然后我处理它.现在一切正常.

Here When I press screen lock key before Initialization first thing I did i.e. I fully Initialized camera and then I dispose it. Now all working fine.

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