スナップショットメソッドが呼び出されたときにnull値を取得する

Question

ブラックベリーカメラアプリケーションを作成しました。 このアプリケーションでは、カメラを起動したときに自動的に写真を撮ろうとします。 私のカメラが呼び出されましたが、自動的に写真を撮っていません。 私はこのコードに従っています。

public class Test extends MainScreen implements FileSystemJournalListener { 
    long _lastUSN; 
    ButtonField btnTakePhoto; 
    String capturedImgPath = ""; 
    VideoControl videoControl; 
    Timer objTimer; 
    Player player; 


    public Test() 
    { 
     super(); 
     btnTakePhoto = new ButtonField("Take Picture",ButtonField.VCENTER|ButtonField.BOTTOM); 
     btnTakePhoto.setChangeListener(TakePictureListener); 

     HorizontalFieldManager hfm=new HorizontalFieldManager();  
     hfm.add(btnTakePhoto); 
     add(hfm); 

     System.out.println("Inside Construct"); 
     UiApplication.getUiApplication().addFileSystemJournalListener(this); 
     _lastUSN = FileSystemJournal.getNextUSN(); 
     this.setTitle("Camera Class"); 


    } 

    public void backGroundPaint(Graphics g) 
    { 
     System.out.println("Inside backGroundPaint"); 
     g.setBackgroundColor(Color.PINK); 
     g.clear(); 

    } 

    FieldChangeListener TakePictureListener = new FieldChangeListener(){ 

     public void fieldChanged(Field field, int context) { 
      System.out.println("Inside fieldChanged"); 
      doTakePicture(); 
     } 
    }; 
    public void doTakePicture(){ 
     try 
     { 

      System.out.println("Inside doTakePicture"); 
      Invoke.invokeApplication(Invoke.APP_TYPE_CAMERA,new CameraArguments()); 
      player = javax.microedition.media.Manager.createPlayer("capture://video??encoding=jpeg&width=240&height=240"); 
      player.realize(); 
      videoControl = (VideoControl) player.getControl("VideoControl"); 

      player.start(); 



      if(videoControl!=null) 
      { 
       Field videoField = (Field) videoControl.initDisplayMode (VideoControl.USE_GUI_PRIMITIVE, "net.rim.device.api.ui.Field"); 


       videoControl.setDisplayFullScreen(true); 
       add((Field) videoControl); 
       videoControl.setVisible(true); 



      } 



     } 



    catch(Exception ex) 
    { 
     System.out.println(ex); 
     Dialog.alert(toString()); 

    } 
    } 

    public void invokeAction() 
    { 

     doTakePicture(); 

      System.out.println("Inside Invoke Action"); 
      try { 
       byte[] snapshot = videoControl.getSnapshot(null); 
       //player.close(); 
       System.out.println("snapshot=="+snapshot); 
       EncodedImage bitmap=EncodedImage.createEncodedImage(snapshot, 0, snapshot.length); 
       System.out.println("bitmap=="+bitmap); 
       BitmapField field1 = new BitmapField(); 
       System.out.println("field1=="+field1); 
       field1.setImage(bitmap); 
       add(field1); 
      } catch (MediaException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 



} 



    public void fileJournalChanged() 
    { 

    System.out.println("Inside fileJournalChanged"); 
     long nextUSN = FileSystemJournal.getNextUSN(); 
     String msg = null; 
     String path = null; 
     for (long lookUSN = nextUSN - 1; lookUSN >= _lastUSN && msg == null; --lookUSN) 
     { 
      FileSystemJournalEntry entry = FileSystemJournal.getEntry(lookUSN); 

      if (entry == null) 
      { 
       break; 
      } 

      path = entry.getPath(); 
      System.out.println("Path=="+path); 

      if (path != null)    
      { 
      if (path.endsWith("png") || path.endsWith("jpg") || path.endsWith("bmp") || path.endsWith("gif")){  
       switch (entry.getEvent()) 
       { 


        case FileSystemJournalEntry.FILE_ADDED: 
         System.out.println("Inside FILE_ADDED"); 
         msg = "File was added."; 
         break; 

        case FileSystemJournalEntry.FILE_DELETED: 
         System.out.println("Inside FILE_DELETED"); 
         msg = "File was deleted."; 
         break; 
       } 
      } 
      } 
     } 
     _lastUSN = nextUSN; 

     if (msg != null) 
     { 
      Dialog.alert(msg); 
      capturedImgPath = path; 
      closeCamera(); 
     } 
    } 
    private void closeCamera() 
    { 
     int menuOrder =6; 
     System.out.println("Inside Close Camera"); 
     EventInjector.invokeEvent(new EventInjector.KeyCodeEvent(EventInjector.KeyCodeEvent.KEY_DOWN, (char)Keypad.KEY_MENU, KeypadListener.STATUS_NOT_FROM_KEYPAD, 0)); 
     EventInjector.invokeEvent(new EventInjector.TrackwheelEvent(EventInjector.TrackwheelEvent.THUMB_ROLL_DOWN, menuOrder, KeypadListener.STATUS_NOT_FROM_KEYPAD)); 
     EventInjector.invokeEvent(new EventInjector.TrackwheelEvent(EventInjector.TrackwheelEvent.THUMB_CLICK, 1, KeypadListener.STATUS_NOT_FROM_KEYPAD)); 
     Dialog.alert("The captured Image path is "+capturedImgPath); 
    } 



} 

Answer 1

このコードを試してください。

import javax.microedition.media.Player; 
import javax.microedition.media.control.VideoControl; 

import net.rim.device.api.system.Bitmap; 
import net.rim.device.api.ui.Field; 
import net.rim.device.api.ui.UiApplication; 
import net.rim.device.api.ui.component.BitmapField; 
import net.rim.device.api.ui.component.Dialog; 
import net.rim.device.api.ui.container.MainScreen; 

public class ImageCaptureDemo extends UiApplication 
{ 
    public static void main(String[] args) 
    { 
     ImageCaptureDemo app = new ImageCaptureDemo(); 
     app.enterEventDispatcher(); 
    } 

public ImageCaptureDemo() 
{ 
    pushScreen(new ImageCaptureDemoScreen()); 
} 

class ImageCaptureDemoScreen extends MainScreen 
{ 
    Player _p; 
    VideoControl _videoControl;  

    public ImageCaptureDemoScreen() 
    { 
     try 
     { 
      _p = javax.microedition.media.Manager.createPlayer("capture://video?encoding=jpeg&width=1024&height=768"); 
      _p.realize(); 
      _videoControl = (VideoControl) _p.getControl("VideoControl"); 

      if (_videoControl != null) 
      { 
       Field videoField = (Field) _videoControl.initDisplayMode (VideoControl.USE_GUI_PRIMITIVE, "net.rim.device.api.ui.Field"); 
       _videoControl.setDisplayFullScreen(true); 
       _videoControl.setVisible(true); 
       _p.start(); 

       /*EnhancedFocusControl efc = (EnhancedFocusControl)p.getControl("net.rim.device.api.amms.control.camera.EnhancedFocusControl"); 
       efc.startAutoFocus();*/ 

       if(videoField != null) 
       { 
        add(videoField); 
       } 
      } 
     } 
     catch(Exception e) 
     { 
      Dialog.alert(e.toString()); 
     } 
    } 

    protected boolean invokeAction(int action) 
    { 
     boolean handled = super.invokeAction(action); 

     if(!handled) 
     { 
      if(action == ACTION_INVOKE) 
      { 
       try 
       {      
        byte[] rawImage = _videoControl.getSnapshot(null); 
        Bitmap image = Bitmap.createBitmapFromBytes(rawImage, 0, rawImage.length, 100); 
        BitmapField bitmapField = new BitmapField(); 
        bitmapField.setBitmap(image); 
        this.add(bitmapField); 


       } 
       catch(Exception e) 
       { 
        Dialog.alert(e.toString()); 
       } 
      } 
     }   
     return handled;     
    } 
} 

}