Question

使用VideoControl.getSnapshot（）方法拍照时遇到问题。它总是抛出异常：不支持getSnapshot。我正在使用JRE 5.0.0与Eclipse和BlackBerry®Java®SDK5.0插件。

我首先要使用命令System.getProperty（“video.snapshot.encodings”）列出所选Blackberry SmartPhone支持的编码（粗体9700），然后从列表中选择一个编码并将其作为getSnapshot参数传递

我已经在几个Blackberry上测试了同样的异常。

部分代码：

mPlayer = Manager.createPlayer("capture://video?encoding=video/3gpp");

mPlayer.realize();

mPlayer = Manager.createPlayer("capture://video?encoding=video/3gpp");

mPlayer.start();

videoControl = (VideoControl)mPlayer.getControl("VideoControl");

Field cameraView = (Field) videoControl.initDisplayMode(VideoControl.USE_GUI_PRIMITIVE, "net.rim.device.api.ui.Field");

Thread.sleep(1000);

UiApplication.getUiApplication().pushScreen(new TempScreen(cameraView));

byte[] snapShot = videoControl.getSnapshot("encoding=jpeg&width=480&height=360&quality=superfine");

Bitmap image = Bitmap.createBitmapFromBytes(snapShot, 0, snapShot.length, 1);

UiApplication.getUiApplication().pushScreen(new TempScreen(image));

}catch (MediaException e){
UiApplication.getUiApplication().pushScreen(new TempScreen("Exception: " + e.getMessage())); }

catch (IOException e){
UiApplication.getUiApplication().pushScreen(new TempScreen("IO Exception: " + e.getMessage())); 
}

catch (InterruptedException e){UiApplication.getUiApplication().pushScreen(new TempScreen("Interrupted Exception: "+ e.getMessage()));}

Answer 1

在一年半以上的时间里，我的回答并不确定，但可能会有用。

您可以尝试使用Thread.sleep（1000）;在getSnapshot（）调用之前。问题可能与这个事实有关：“在调用getSnapShot（）之前，取景器必须在屏幕上显示。”

因此，如果您在

UiApplication.getUiApplication().pushScreen(new TempScreen(cameraView));

之后立即致电getSnapshot 相机没有为下一次拍摄做好准备。

您是否确定您的设备上完全支持getSnapshot（）API？尽管API定义了这种方法，但有些制造商可能不支持它。您是否在测试getSnapshot（）的同一设备上运行了System.getProperty（“video.snapshot.encodings”）？

Answer 2

  Player _p;
  VideoControl _vc ;
  RecordControl _rc ;
  String PATH;
  FileConnection fileconn;
  Object canvas= new Object();

  public static boolean SdcardAvailabulity() {
         String root = null;
         Enumeration e = FileSystemRegistry.listRoots();
         while (e.hasMoreElements()) {
             root = (String) e.nextElement();
             if( root.equalsIgnoreCase("sdcard/") ) {
                 return true;
             }else if( root.equalsIgnoreCase("store/") ) {
                 return false;
             }
         }
         class MySDListener implements FileSystemListener {
             public void rootChanged(int state, String rootName) {
                 if( state == ROOT_ADDED ) {
                     if( rootName.equalsIgnoreCase("sdcard/") ) {
                     }
                 } else if( state == ROOT_REMOVED ) {
                 }
             }
         }
         return true;
    }
protected boolean invokeAction(int action){
      boolean handled = super.invokeAction(action); 
      if(SdcardAvailabulity()){
          PATH = System.getProperty("fileconn.dir.memorycard.videos")+"Video_"+System.currentTimeMillis()+".3gpp";//here "str" having the current Date and Time;
      } else {
          PATH = System.getProperty("fileconn.dir.videos")+"Video_"+System.currentTimeMillis()+".3gpp"; 
      }
      if(!handled){
          if(action == ACTION_INVOKE){   
              try{     

                  if(_p!=null)
                      _p.close();  
              }catch(Exception e){
              }
          }
      }
    return handled;
  }
  public MyScreen(){
      setTitle("Video recording demo");
      ButtonField AddPhoto = new ButtonField("push",ButtonField.FOCUSABLE | ButtonField.FIELD_HCENTER | ButtonField.FIELD_VCENTER | DrawStyle.HCENTER | ButtonField.NEVER_DIRTY | Field.USE_ALL_WIDTH);
      FieldChangeListener PhotoListener = new FieldChangeListener() {
          public void fieldChanged(Field field, int context) {
              ButtonField  Button = (ButtonField) field;
              if (Button.getLabel().equals("push")){


              }
          }
      };
      AddPhoto.setChangeListener(PhotoListener);
      add(AddPhoto);
  }
}

Blackberry不支持getSnapshot

2 个答案: