初始化時發生PhotoCamera問題

我正在開發使用PhotoCamera捕獲圖像的windows phone 8應用程序。當我按屏幕鎖定鍵時出現問題。當我按下鎖定鍵時，我的PhotoCamera物體不處理。當我在Camera Initialization時按屏幕鎖鍵時，我遇到問題。初始化時發生PhotoCamera問題

這是一些代碼。

按鈕點擊代碼

_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);

這裏是我的OnPhotoCameraInitialized代碼

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); 
     } 
}

這裏是我的NavigationFrom代碼

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); 
     } 
}

我在的OnNavigatedTo方法

這裏是的OnNavigatedTo代碼重新初始化photocamera。

  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); 
        } 
       } 
      }

基本上我想要做的是捕獲圖片並顯示它。在照相機初始化之前按下鎖定鍵時出現問題。當我按下鎖定鍵時，OnNavigatedFrom代碼開始執行。當達到if(cameraInit)內部代碼不執行時，因爲cameraInit不正確。我在OnPhotoCameraInitialized方法中設置了cameraInit = true;。但不幸的是這個代碼塊沒有執行。所以我的問題是如何處理相機對象？只有當它完全初始化時，我才能處置它。但是我在Initialization之前按下了鎖定鍵。有什麼方法可以清潔視頻畫筆嗎？

來源

2014-01-09 Ajay Punekar

你好，我所有的問題都解決了。

我更改了OnNavigatedFrom和OnPhotoCameraInitialized中的代碼。

這裏是代碼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; 
        } 
       }); 
      }

這裏是我的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(); 
        } 
       }); 
      }

這裏的時候，我按我做即我完全初始化相機，然後screen lock key前初始化第一件事我dispose它。現在一切正常。

來源

2014-01-10 07:39:21

初始化時發生PhotoCamera問題

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