本帖最后由 Shims 于 2013-11-9 12:39 编辑
最近公司的Android项目需要用到摄像头做条码或二维码的扫描,Google一下,发现一个开源的 ZXing项目。它提供二维码和条形码的扫描。扫描条形码就是直接读取条形码的内容,扫描二维码是按照自己指定的二维码格式进行编码和解码。
1.什么是二维码和条形码?
二维条形码最早发明于日本,它是用某种特定的几何图形按一定规律在平面(二维方向上)分布的黑白相间的图形记录数据符号信息的,在代码编制上巧妙地利用构成计算机内部逻辑基础的“0”、“1”比特流的概念,使用若干个与二进制相对应的几何形体来表示文字数值信息,通过图象输入设备或光电扫描设备自动识读以实现信息自动处理。它具有条码技术的一些共性:每种码制有其特定的字符集;每个字符占有一定的宽度;具有一定的校验功能等。同时还具有对不同行的信息自动识别功能、及处理图形旋转变化等特点。
条形码(barcode)是将宽度不等的多个黑条和空白,按照一定的编码规则排列,用以表达一组信息的图形标识符。常见的条形码是由反射率相差很大的黑条(简称条)和白条(简称空)排成的平行线图案。条形码可以标出物品的生产国、制造厂家、商品名称、生产日期、图书分类号、邮件起止地点、类别、日期等许多信息,因而在商品流通、图书管理、邮政管理、银行系统等许多领域都得到广泛的应用。
2.ZXing基本介绍
ZXing是一个开源Java类库用于解析多种格式的条形码和二维码.官网:http://code.google.com/p/zxing/
截止目前为止最新版本提供以下编码格式的支持:
- UPC-A and UPC-E
- EAN-8 and EAN-13
- Code 39
- Code 93
- Code 128
- QR Code
- ITF
- Codabar
- RSS-14 (all variants)
- Data Matrix
- PDF 417 ('alpha' quality)
- Aztec ('alpha' quality)
同时官网提供了 Android、cpp、C#、iPhone、j2me、j2se、jruby、objc、rim、symbian等多种应用的类库,具体详情可以参考下载的源码包中。
3.Android端编码演示
这里使用的ZXing是经过简化版的,去除了一些一般使用不必要的文件,项目工程和效果截图如下:
其中encoding包是在原基础上加上去的,功能是根据传入的字符串来生成二维码图片,返回一个Bitmap,其余的包是ZXing项目自带的。另外对扫描界面的布局也进行了修改,官方的扫描界面是横向的,我改成了纵向的,并加入了顶部的Tab和取消按钮(camera.xml),另外还需要的一些文件是colors.xml、ids.xml,这些都是原本ZXing项目中自带的,最后就是libs下面的jar包。
接下来看如何使用,首先是把ZXing项目中的一些文件拷贝到我们自己的项目中,然后在Mainifest文件中进行配置权限:
- <font color="#000"><font face="Arial"> <uses-permission android:name="android.permission.VIBRATE" />
- <uses-permission android:name="android.permission.CAMERA" />
- <uses-feature android:name="android.hardware.camera" />
- <uses-feature android:name="android.hardware.camera.autofocus" /></font></font>
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还有就是扫描界面Activity的配置:
- <font color="#000"> <activity
- android:configChanges="orientation|keyboardHidden"
- android:name="com.zxing.activity.CaptureActivity"
- android:screenOrientation="portrait"
- android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
- android:windowSoftInputMode="stateAlwaysHidden" >
- </activity></font>
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接下来是我自己项目的布局文件:
- <font color="#000"><font face="Arial"><?xml version="1.0" encoding="utf-8"?>
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent"
- android:background="@android:color/white"
- android:orientation="vertical" >
- <Button
- android:id="@+id/btn_scan_barcode"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:layout_marginTop="30dp"
- android:text="Open camera" />
- <LinearLayout
- android:orientation="horizontal"
- android:layout_marginTop="10dp"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content">
- <TextView
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:textColor="@android:color/black"
- android:textSize="18sp"
- android:text="Scan result:" />
- <TextView
- android:id="@+id/tv_scan_result"
- android:layout_width="fill_parent"
- android:textSize="18sp"
- android:textColor="@android:color/black"
- android:layout_height="wrap_content" />
- </LinearLayout>
- <EditText
- android:id="@+id/et_qr_string"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:layout_marginTop="30dp"
- android:hint="Input the text"/>
- <Button
- android:id="@+id/btn_add_qrcode"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:text="Generate QRcode" />
- <ImageView
- android:id="@+id/iv_qr_image"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:layout_marginTop="10dp"
- android:layout_gravity="center"/>
- </LinearLayout></font></font>
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下面是主Activity的代码,主要功能是打开扫描框、显示扫描结果、根据输入的字符串生成二维码图片:
- <font color="#000"><font face="Arial">public class BarCodeTestActivity extends Activity {
- /** Called when the activity is first created. */
- private TextView resultTextView;
- private EditText qrStrEditText;
- private ImageView qrImgImageView;
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- resultTextView = (TextView) this.findViewById(R.id.tv_scan_result);
- qrStrEditText = (EditText) this.findViewById(R.id.et_qr_string);
- qrImgImageView = (ImageView) this.findViewById(R.id.iv_qr_image);
- Button scanBarCodeButton = (Button) this.findViewById(R.id.btn_scan_barcode);
- scanBarCodeButton.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- //打开扫描界面扫描条形码或二维码
- Intent openCameraIntent = new Intent(BarCodeTestActivity.this,CaptureActivity.class);
- startActivityForResult(openCameraIntent, 0);
- }
- });
- Button generateQRCodeButton = (Button) this.findViewById(R.id.btn_add_qrcode);
- generateQRCodeButton.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- try {
- String contentString = qrStrEditText.getText().toString();
- if (!contentString.equals("")) {
- //根据字符串生成二维码图片并显示在界面上,第二个参数为图片的大小(350*350)
- Bitmap qrCodeBitmap = EncodingHandler.createQRCode(contentString, 350);
- qrImgImageView.setImageBitmap(qrCodeBitmap);
- }else {
- Toast.makeText(BarCodeTestActivity.this, "Text can not be empty", Toast.LENGTH_SHORT).show();
- }
- } catch (WriterException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- }
- });
- }
- @Override
- protected void onActivityResult(int requestCode, int resultCode, Intent data) {
- super.onActivityResult(requestCode, resultCode, data);
- //处理扫描结果(在界面上显示)
- if (resultCode == RESULT_OK) {
- Bundle bundle = data.getExtras();
- String scanResult = bundle.getString("result");
- resultTextView.setText(scanResult);
- }
- }
- }</font></font>
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其中生成二维码图片的代码在EncodingHandler.java中:
- <font color="#000"><font face="Arial">public final class EncodingHandler {
- private static final int BLACK = 0xff000000;
- public static Bitmap createQRCode(String str,int widthAndHeight) throws WriterException {
- Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>();
- hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
- BitMatrix matrix = new MultiFormatWriter().encode(str,
- BarcodeFormat.QR_CODE, widthAndHeight, widthAndHeight);
- int width = matrix.getWidth();
- int height = matrix.getHeight();
- int[] pixels = new int[width * height];
- for (int y = 0; y < height; y++) {
- for (int x = 0; x < width; x++) {
- if (matrix.get(x, y)) {
- pixels[y * width + x] = BLACK;
- }
- }
- }
- Bitmap bitmap = Bitmap.createBitmap(width, height,
- Bitmap.Config.ARGB_8888);
- bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
- return bitmap;
- }
- }</font></font>
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最后是在哪里对扫描结果进行解码,进入CaptureActivity.java找到下面这个方法便可以对自己对结果进行操作:
- <font color="#000"><font face="Arial"> /**
- * Handler scan result
- * @param result
- * @param barcode
- */
- public void handleDecode(Result result, Bitmap barcode) {
- inactivityTimer.onActivity();
- playBeepSoundAndVibrate();
- String resultString = result.getText();
- //FIXME
- if (resultString.equals("")) {
- Toast.makeText(CaptureActivity.this, "Scan failed!", Toast.LENGTH_SHORT).show();
- }else {
- // System.out.println("Result:"+resultString);
- Intent resultIntent = new Intent();
- Bundle bundle = new Bundle();
- bundle.putString("result", resultString);
- resultIntent.putExtras(bundle);
- this.setResult(RESULT_OK, resultIntent);
- }
- CaptureActivity.this.finish();
- }</font></font>
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4.Java端编码演示
在Java端上实现条形码(EAN-13)和二维码(QRCode) 的编码和解码的示例,以供大家参考,用到了源码中core和javase下面的相关源代码,附件提供自己编译之后的lib包:
zxing.jar zxing-j2se.jar
有关各种手机系统的应用,有兴趣的朋友可以下载官方源码包,包下有具体详细的应用介绍。
1)二维码(QRCode)的编码和解码演示:
编码示例:
- package michael.zxing;
- import java.io.File;
- import java.util.Hashtable;
- import com.google.zxing.BarcodeFormat;
- import com.google.zxing.EncodeHintType;
- import com.google.zxing.MultiFormatWriter;
- import com.google.zxing.client.j2se.MatrixToImageWriter;
- import com.google.zxing.common.BitMatrix;
- import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
- /**
- * [url=home.php?mod=space&uid=618199]@blog[/url] http://sjsky.iteye.com
- * @author Michael
- */
- public class ZxingEncoderHandler {
- /**
- * 编码
- * @param contents
- * @param width
- * @param height
- * @param imgPath
- */
- public void encode(String contents, int width, int height, String imgPath) {
- Hashtable<Object, Object> hints = new Hashtable<Object, Object>();
- // 指定纠错等级
- hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);
- // 指定编码格式
- hints.put(EncodeHintType.CHARACTER_SET, "GBK");
- try {
- BitMatrix bitMatrix = new MultiFormatWriter().encode(contents,
- BarcodeFormat.QR_CODE, width, height, hints);
- MatrixToImageWriter
- .writeToFile(bitMatrix, "png", new File(imgPath));
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- /**
- * @param args
- */
- public static void main(String[] args) {
- String imgPath = "d:/1.png";
- String contents = "Hello Word!";
- int width = 300, height = 300;
- ZxingEncoderHandler handler = new ZxingEncoderHandler();
- handler.encode(contents, width, height, imgPath);
- }
- }
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运行后生成的二维码图片如下:
用手机的二维码扫描软件(本人用的:android 快拍二维码 )来测试下,识别成功的截图如下: 解码示例:
- package michael.zxing;
- import java.awt.image.BufferedImage;
- import java.io.File;
- import java.util.Hashtable;
- import javax.imageio.ImageIO;
- import com.google.zxing.BinaryBitmap;
- import com.google.zxing.DecodeHintType;
- import com.google.zxing.LuminanceSource;
- import com.google.zxing.MultiFormatReader;
- import com.google.zxing.Result;
- import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
- import com.google.zxing.common.HybridBinarizer;
- /**
- * @blog http://sjsky.iteye.com
- * @author Michael
- */
- public class ZxingDecoderHandler {
- /**
- * @param imgPath
- * [url=home.php?mod=space&uid=7300]@return[/url] String
- */
- public String decode(String imgPath) {
- BufferedImage image = null;
- Result result = null;
- try {
- image = ImageIO.read(new File(imgPath));
- if (image == null) {
- System.out.println("the decode image may be not exit.");
- }
- LuminanceSource source = new BufferedImageLuminanceSource(image);
- BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
- Hashtable<Object, Object> hints = new Hashtable<Object, Object>();
- hints.put(DecodeHintType.CHARACTER_SET, "utf-8");
- result = new MultiFormatReader().decode(bitmap, hints);
- return result.getText();
- } catch (Exception e) {
- e.printStackTrace();
- }
- return null;
- }
- /**
- * @param args
- */
- public static void main(String[] args) {
- String imgPath = "d:/1.png";
- ZxingDecoderHandler handler = new ZxingDecoderHandler();
- String decodeContent = handler.decode(imgPath);
- System.out.println("解码内容如下:");
- System.out.println(decodeContent);
- }
- }
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Hello Word!
2)条形码(EAN-13)的编码和解码演示:
编码示例:
- package michael.zxing;
- import java.io.File;
- import com.google.zxing.BarcodeFormat;
- import com.google.zxing.MultiFormatWriter;
- import com.google.zxing.client.j2se.MatrixToImageWriter;
- import com.google.zxing.common.BitMatrix;
- /**
- * @blog http://sjsky.iteye.com
- * @author Michael
- */
- public class ZxingEAN13EncoderHandler {
- /**
- * 编码
- * @param contents
- * @param width
- * @param height
- * @param imgPath
- */
- public void encode(String contents, int width, int height, String imgPath) {
- int codeWidth = 3 + // start guard
- (7 * 6) + // left bars
- 5 + // middle guard
- (7 * 6) + // right bars
- 3; // end guard
- codeWidth = Math.max(codeWidth, width);
- try {
- BitMatrix bitMatrix = new MultiFormatWriter().encode(contents,
- BarcodeFormat.EAN_13, codeWidth, height, null);
- MatrixToImageWriter
- .writeToFile(bitMatrix, "png", new File(imgPath));
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- /**
- * @param args
- */
- public static void main(String[] args) {
- String imgPath = "d:/2.png";
- // 益达无糖口香糖的条形码
- String contents = "6923450657713";
- int width = 105, height = 50;
- ZxingEAN13EncoderHandler handler = new ZxingEAN13EncoderHandler();
- handler.encode(contents, width, height, imgPath);
- }
- }
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运行后生成条形码图片如下:
用手机的条形码扫描软件(本人用的:android 快拍二维码 )来测试下,识别成功的截图如下:
解码示例:
- package michael.zxing;
- import java.awt.image.BufferedImage;
- import java.io.File;
- import javax.imageio.ImageIO;
- import com.google.zxing.BinaryBitmap;
- import com.google.zxing.LuminanceSource;
- import com.google.zxing.MultiFormatReader;
- import com.google.zxing.Result;
- import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
- import com.google.zxing.common.HybridBinarizer;
- /**
- * @blog http://sjsky.iteye.com
- * @author Michael
- */
- public class ZxingEAN13DecoderHandler {
- /**
- * @param imgPath
- * @return String
- */
- public String decode(String imgPath) {
- BufferedImage image = null;
- Result result = null;
- try {
- image = ImageIO.read(new File(imgPath));
- if (image == null) {
- System.out.println("the decode image may be not exit.");
- }
- LuminanceSource source = new BufferedImageLuminanceSource(image);
- BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
- result = new MultiFormatReader().decode(bitmap, null);
- return result.getText();
- } catch (Exception e) {
- e.printStackTrace();
- }
- return null;
- }
- /**
- * @param args
- */
- public static void main(String[] args) {
- String imgPath = "d:/2.png";
- ZxingEAN13DecoderHandler handler = new ZxingEAN13DecoderHandler();
- String decodeContent = handler.decode(imgPath);
- System.out.println("解码内容如下:");
- System.out.println(decodeContent);
- }
- }
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解码内容如下:
6923450657713
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