Android下利用zbar類庫實現掃一掃

程序源代碼及可執行文件下載地址:http://files.cnblogs.com/rainboy2010/zbardemo.zip

Android下常用的條碼掃描類庫有zxing和zbar,比較了一下,發現zbar掃描速度更快,能夠識別的條碼類型更多,下面就講解一下如何利用zbar實現掃一掃,先放上一張效果圖:

主要代碼如下:

 1.在onPreviewFrame方法里獲取預覽圖像，然后傳遞給DecodeHandler去解析

 @Override
  public void onPreviewFrame(byte[] data, Camera camera) 
  {
	 if (!useOneShotPreviewCallback) 
	 {
	   camera.setPreviewCallback(null);
	 }
	 if(previewHandler != null) 
	 {
		Camera.Parameters parameters = camera.getParameters();
	    Size size = parameters.getPreviewSize();
	    Message message = previewHandler.obtainMessage(previewMessage, size.width,size.height, data);
	    message.sendToTarget();
	    previewHandler = null;
	 } 
	 else 
	 {
	    Log.d(TAG, "Got preview callback, but no handler for it"); 
	 }
	 
   }

2. 在decode方法里調用zbar類庫對圖像進行解析

 private void decode(byte[] data, int width, int height) {

    Image barcode = new Image(width, height, "Y800");
	Rect scanImageRect = activity.getViewfinderView().getScanImageRect(height,width);
    barcode.setCrop(scanImageRect.top, scanImageRect.left, scanImageRect.bottom, scanImageRect.right);
    barcode.setData(data);

    int result = scanner.scanImage(barcode);
    String strResult="";
    if (result != 0) 
    {
       SymbolSet syms = scanner.getResults();
       for (Symbol sym : syms)
       {
    	   strResult=sym.getData().trim();
    	   if(!strResult.isEmpty())
    	   {
             break;
    	   }
       }
    }
    
    if(!strResult.isEmpty())
    {
       Message message = Message.obtain(activity.getHandler(), R.id.decode_succeeded, strResult);//Message信息傳來傳去,有點繞
       Log.d(TAG, "Sending decode succeeded message...");
       message.sendToTarget();
    } 
    else 
    {
        Message message = Message.obtain(activity.getHandler(), R.id.decode_failed);
        message.sendToTarget();
    }
  }