Android二維碼開源項目zxing用例簡化和生成二維碼、條形碼

上一篇講到：Android二維碼開源項目zxing編譯，編譯出來後有一個自帶的測試程序：CaptureActivity比較複雜，我僅僅要是把一些不用的東西去掉，用看起來更方便，二維碼和條形碼的流行性自沒必要說了。

自帶的樣例，文件夾結構例如如下：

改動後的程序文件夾結構，去掉了很是多功能，假設分享、設置等。

先上效果圖

        

掃描ZXing生成的條形碼和二維碼結果

掃描界面

掃描商品的條碼

整個程序僅僅改動了下面兩個類，其餘都是直接從原來的Demo中複製出來的

生成二維碼的代碼

/**
	 * 生成二維碼 要轉換的地址或字符串,可以是中文
	 * 
	 * @param url
	 * @param width
	 * @param height
	 * @return
	 */
	public Bitmap createQRImage(String url, final int width, final int height) {
		try {
			// 推斷URL合法性
			if (url == null || "".equals(url) || url.length() < 1) {
				return null;
			}
			Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>();
			hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
			// 圖像數據轉換，使用了矩陣轉換
			BitMatrix bitMatrix = new QRCodeWriter().encode(url,
					BarcodeFormat.QR_CODE, width, height, hints);
			int[] pixels = new int[width * height];
			// 如下這裏依照二維碼的算法，逐個生成二維碼的圖片，
			// 兩個for循環是圖片橫列掃描的結果
			for (int y = 0; y < height; y++) {
				for (int x = 0; x < width; x++) {
					if (bitMatrix.get(x, y)) {
						pixels[y * width + x] = 0xff000000;
					} else {
						pixels[y * width + x] = 0xffffffff;
					}
				}
			}
			// 生成二維碼圖片的格式，使用ARGB_8888
			Bitmap bitmap = Bitmap.createBitmap(width, height,
					Bitmap.Config.ARGB_8888);
			bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
			return bitmap;
		} catch (WriterException e) {
			e.printStackTrace();
		}
		return null;
	}

可以生成中文

生成條形碼關鍵代碼，下面代碼是把條形碼和條形碼下的文字合併成一張圖片顯示。

/**
	 * 生成條形碼
	 * 
	 * @param context
	 * @param contents
	 *            需要生成的內容
	 * @param desiredWidth
	 *            生成條形碼的寬帶
	 * @param desiredHeight
	 *            生成條形碼的高度
	 * @param displayCode
	 *            是否在條形碼下方顯示內容
	 * @return
	 */
	public static Bitmap creatBarcode(Context context, String contents,
			int desiredWidth, int desiredHeight, boolean displayCode) {
		Bitmap ruseltBitmap = null;
		/**
		 * 圖片兩端所保留的空白的寬度
		 */
		int marginW = 20;
		/**
		 * 條形碼的編碼類型
		 */
		BarcodeFormat barcodeFormat = BarcodeFormat.CODE_128;

		if (displayCode) {
			Bitmap barcodeBitmap = encodeAsBitmap(contents, barcodeFormat,
					desiredWidth, desiredHeight);
			Bitmap codeBitmap = creatCodeBitmap(contents, desiredWidth + 2
					* marginW, desiredHeight, context);
			ruseltBitmap = mixtureBitmap(barcodeBitmap, codeBitmap, new PointF(
					0, desiredHeight));
		} else {
			ruseltBitmap = encodeAsBitmap(contents, barcodeFormat,
					desiredWidth, desiredHeight);
		}

		return ruseltBitmap;
	}

	/**
	 * 生成條形碼的Bitmap
	 * 
	 * @param contents
	 *            需要生成的內容
	 * @param format
	 *            編碼格式
	 * @param desiredWidth
	 * @param desiredHeight
	 * @return
	 * @throws WriterException
	 */
	protected static Bitmap encodeAsBitmap(String contents,
			BarcodeFormat format, int desiredWidth, int desiredHeight) {
		final int WHITE = 0xFFFFFFFF;
		final int BLACK = 0xFF000000;

		MultiFormatWriter writer = new MultiFormatWriter();
		BitMatrix result = null;
		try {
			result = writer.encode(contents, format, desiredWidth,
					desiredHeight, null);
		} catch (WriterException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		int width = result.getWidth();
		int height = result.getHeight();
		int[] pixels = new int[width * height];
		// All are 0, or black, by default
		for (int y = 0; y < height; y++) {
			int offset = y * width;
			for (int x = 0; x < width; x++) {
				pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;
			}
		}

		Bitmap bitmap = Bitmap.createBitmap(width, height,
				Bitmap.Config.ARGB_8888);
		bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
		return bitmap;
	}

	/**
	 * 生成顯示編碼的Bitmap
	 * 
	 * @param contents
	 * @param width
	 * @param height
	 * @param context
	 * @return
	 */
	protected static Bitmap creatCodeBitmap(String contents, int width,
			int height, Context context) {
		TextView tv = new TextView(context);
		LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
				LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
		tv.setLayoutParams(layoutParams);
		tv.setText(contents);
		tv.setHeight(height);
		tv.setGravity(Gravity.CENTER_HORIZONTAL);
		tv.setWidth(width);
		tv.setDrawingCacheEnabled(true);
		tv.setTextColor(Color.BLACK);
		tv.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
				MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
		tv.layout(0, 0, tv.getMeasuredWidth(), tv.getMeasuredHeight());

		tv.buildDrawingCache();
		Bitmap bitmapCode = tv.getDrawingCache();
		return bitmapCode;
	}

	/**
	 * 將兩個Bitmap合併成一個
	 * 
	 * @param first
	 * @param second
	 * @param fromPoint
	 *            第二個Bitmap開始繪製的起始位置（相對於第一個Bitmap）
	 * @return
	 */
	protected static Bitmap mixtureBitmap(Bitmap first, Bitmap second,
			PointF fromPoint) {
		if (first == null || second == null || fromPoint == null) {
			return null;
		}
		int marginW = 20;
		Bitmap newBitmap = Bitmap.createBitmap(
				first.getWidth() + second.getWidth() + marginW,
				first.getHeight() + second.getHeight(), Config.ARGB_4444);
		Canvas cv = new Canvas(newBitmap);
		cv.drawBitmap(first, marginW, 0, null);
		cv.drawBitmap(second, fromPoint.x, fromPoint.y, null);
		cv.save(Canvas.ALL_SAVE_FLAG);
		cv.restore();

		return newBitmap;
	}

CaptureActivity.java是掃描二維碼和條形碼的界面，對Camera進行初始化和開啓掃描線程

private void initCamera(SurfaceHolder surfaceHolder) {
		if (surfaceHolder == null) {
			throw new IllegalStateException("No SurfaceHolder provided");
		}
		if (cameraManager.isOpen()) {
			ZXingApplication
					.print_i("CaptureActivity",
							"initCamera() while already open -- late SurfaceView callback?");
			return;
		}

		try {
			cameraManager.openDriver(surfaceHolder);
		} catch (IOException ioe) {
			return;
		} catch (RuntimeException e) {
			return;
		}
		if (handler == null) {
			handler = new CaptureActivityHandler(this, decodeFormats,
					decodeHints, characterSet, cameraManager);
		}
		ZXingApplication.print_i("CaptureActivity",
				"initCamera-----------finish");
	}

在CaptureActivityHandler.java類中會處理掃描的結果

@Override
	public void handleMessage(Message message) {
		switch (message.what) {
		case R.id.restart_preview:
			restartPreviewAndDecode();
			break;
		case R.id.decode_succeeded:
			state = State.SUCCESS;
			Bundle bundle = message.getData();
			Bitmap barcode = null;
			float scaleFactor = 1.0f;
			if (bundle != null) {
				byte[] compressedBitmap = bundle
						.getByteArray(DecodeThread.BARCODE_BITMAP);
				if (compressedBitmap != null) {
					barcode = BitmapFactory.decodeByteArray(compressedBitmap,
							0, compressedBitmap.length, null);
					// Mutable copy:
					barcode = barcode.copy(Bitmap.Config.ARGB_8888, true);
				}
				scaleFactor = bundle
						.getFloat(DecodeThread.BARCODE_SCALED_FACTOR);
			}
			activity.handleDecode((Result) message.obj, barcode, scaleFactor);
			break;
		case R.id.decode_failed:
			// We're decoding as fast as possible, so when one decode fails,
			// start another.
			state = State.PREVIEW;
			cameraManager.requestPreviewFrame(decodeThread.getHandler(),
					R.id.decode);
			break;
		case R.id.return_scan_result:
			activity.setResult(Activity.RESULT_OK, (Intent) message.obj);
			activity.finish();
			break;
		case R.id.launch_product_query:
			String url = (String) message.obj;

			Intent intent = new Intent(Intent.ACTION_VIEW);
			intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
			intent.setData(Uri.parse(url));

			ResolveInfo resolveInfo = activity.getPackageManager()
					.resolveActivity(intent, PackageManager.MATCH_DEFAULT_ONLY);
			String browserPackageName = null;
			if (resolveInfo != null && resolveInfo.activityInfo != null) {
				browserPackageName = resolveInfo.activityInfo.packageName;
				Log.d(TAG, "Using browser in package " + browserPackageName);
			}

			// Needed for default Android browser / Chrome only apparently
			if ("com.android.browser".equals(browserPackageName)
					|| "com.android.chrome".equals(browserPackageName)) {
				intent.setPackage(browserPackageName);
				intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
				intent.putExtra(Browser.EXTRA_APPLICATION_ID,
						browserPackageName);
			}

			try {
				activity.startActivity(intent);
			} catch (ActivityNotFoundException ignored) {
				Log.w(TAG, "Can't find anything to handle VIEW of URI " + url);
			}
			break;
		}
	}

在case R.id.decode_succeeded 分支會經過activity.handleDecode((Result) message.obj, barcode, scaleFactor);回傳結果給Activity

/**
	 * A valid barcode has been found, so give an indication of success and show
	 * the results.
	 * 
	 * @param rawResult
	 *            The contents of the barcode.
	 * @param scaleFactor
	 *            amount by which thumbnail was scaled
	 * @param barcode
	 *            A greyscale bitmap of the camera data which was decoded.
	 */
	public void handleDecode(final Result rawResult, Bitmap barcode,
			float scaleFactor) {
		inactivityTimer.onActivity();
		// ResultHandler resultHandler = ResultHandlerFactory.makeResultHandler(
		// this, rawResult);

		boolean fromLiveScan = barcode != null;
		AlertDialog.Builder dialog = new AlertDialog.Builder(this);
		if (barcode == null) {
			dialog.setIcon(null);
		} else {

			Drawable drawable = new BitmapDrawable(barcode);
			dialog.setIcon(drawable);
		}
		dialog.setTitle("掃描結果");
		dialog.setMessage(rawResult.getText());
		dialog.setNegativeButton("肯定", new DialogInterface.OnClickListener() {
			@Override
			public void onClick(DialogInterface dialog, int which) {
				// 用默認瀏覽器打開掃描獲得的地址
				Intent intent = new Intent();
				intent.setAction("android.intent.action.VIEW");
				Uri content_url = Uri.parse(rawResult.getText());
				intent.setData(content_url);
				startActivity(intent);
				finish();
			}
		});
		dialog.setPositiveButton("取消", new DialogInterface.OnClickListener() {
			@Override
			public void onClick(DialogInterface dialog, int which) {
				finish();
			}
		});
		dialog.create().show();
	}

這裏僅僅是把掃描的結果顯示出來，實際上可以依據不一樣的需要來處理，假設掃描出二維碼可以用HTTP來打開，有一點要注意的，個人ADT版本號是V23.0.2.1259578，需要執行的4.0的系統上

演示樣例代碼：http://download.csdn.net/detail/deng0zhaotai/7696615