在Android上使用ZXing识别条形码/二维码

 越来越多的手机具备自动对焦的拍摄功能,这也意味着这些手机可以具备条码扫描的功能.......手机具备条码扫描的功能,可以优化购物流程,快速存储电子名片(二维码)等

本文使用ZXing 1.6实现条码/二维码识别。ZXing是个很经典的条码/二维码识别的开源类库,long long ago,就有开发者在J2ME上使用ZXing了,不过要支持JSR-234规范(自动对焦)的手机才能发挥其威力,而目前已经有不少Android手机具备自动对焦的功能。

本文代码运行的结果如下,使用91手机助手截图时,无法截取SurfaceView的实时图像:

在Android上使用ZXing识别条形码/二维码_第1张图片

在Android上使用ZXing识别条形码/二维码_第2张图片

在Android上使用ZXing识别条形码/二维码_第3张图片

本文使用了ZXing1.6的core,即把/zxing-1.6/core/下的src复制覆盖工程的src;另外还要使用到/zxing-1.6/android/下的PlanarYUVLuminanceSource.java。

PS:/zxing-1.6/android/ 是BarcodeScanner的源码,本文程序相当于BarcodeScanner的精简版,只保留最基本的识别功能。

本文源码工程的下载地址如下:http://www.pudn.com/downloads349/sourcecode/comm/android/detail1521939.html

源码目录结果如下图,ChecksumException.java下面还有很多源文件,截图尚未列出:

在Android上使用ZXing识别条形码/二维码_第4张图片

本文例子必须要开摄像头和自动对焦的权限,不然启动时会报异常,所用的权限如下:

[xhtml] view plain copy print ?
  1. <uses-permission android:name="android.permission.CAMERA"></uses-permission>
  2. <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
  3. <uses-feature android:name="android.hardware.camera" />
  4. <uses-feature android:name="android.hardware.camera.autofocus" />
<uses-permission android:name="android.permission.CAMERA"></uses-permission> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission> <uses-feature android:name="android.hardware.camera" /> <uses-feature android:name="android.hardware.camera.autofocus" />

main.xml源码如下,main.xml必须要用到FrameLayout才能重叠控件实现“范围框”的效果:

[xhtml] view plain copy print ?
  1. <?xml version="1.0" encoding="utf-8"?>
  2. <FrameLayout android:id="@+id/FrameLayout01"
  3. android:layout_width="fill_parent" android:layout_height="fill_parent"
  4. xmlns:android="http://schemas.android.com/apk/res/android">
  5. <SurfaceView android:layout_height="fill_parent"
  6. android:id="@+id/sfvCamera" android:layout_width="fill_parent"></SurfaceView>
  7. <RelativeLayout android:id="@+id/RelativeLayout01"
  8. android:layout_height="fill_parent" android:layout_width="fill_parent">
  9. <ImageView android:id="@+id/ImageView01"
  10. android:layout_height="100dip" android:layout_width="160dip"></ImageView>
  11. <View android:layout_centerVertical="true"
  12. android:layout_centerHorizontal="true" android:layout_width="300dip"
  13. android:background="#55FF6666" android:id="@+id/centerView"
  14. android:layout_height="180dip"></View>
  15. <TextView android:layout_centerHorizontal="true"
  16. android:layout_width="wrap_content" android:layout_below="@+id/centerView"
  17. android:layout_height="wrap_content" android:text="Scanning..."
  18. android:id="@+id/txtScanResult" android:textColor="#FF000000"></TextView>
  19. </RelativeLayout>
  20. </FrameLayout>
<?xml version="1.0" encoding="utf-8"?> <FrameLayout android:id="@+id/FrameLayout01" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android"> <SurfaceView android:layout_height="fill_parent" android:id="@+id/sfvCamera" android:layout_width="fill_parent"></SurfaceView> <RelativeLayout android:id="@+id/RelativeLayout01" android:layout_height="fill_parent" android:layout_width="fill_parent"> <ImageView android:id="@+id/ImageView01" android:layout_height="100dip" android:layout_width="160dip"></ImageView> <View android:layout_centerVertical="true" android:layout_centerHorizontal="true" android:layout_width="300dip" android:background="#55FF6666" android:id="@+id/centerView" android:layout_height="180dip"></View> <TextView android:layout_centerHorizontal="true" android:layout_width="wrap_content" android:layout_below="@+id/centerView" android:layout_height="wrap_content" android:text="Scanning..." android:id="@+id/txtScanResult" android:textColor="#FF000000"></TextView> </RelativeLayout> </FrameLayout>

testCamera.java是主类,负责控制Camera和对图像做解码,源码如下:

[java] view plain copy print ?
  1. package com.testCamera;
  2. import java.util.Timer;
  3. import java.util.TimerTask;
  4. import com.google.zxing.BinaryBitmap;
  5. import com.google.zxing.MultiFormatReader;
  6. import com.google.zxing.Result;
  7. import com.google.zxing.Android.PlanarYUVLuminanceSource;
  8. import com.google.zxing.common.HybridBinarizer;
  9. import android.app.Activity;
  10. import android.graphics.Bitmap;
  11. import android.hardware.Camera;
  12. import android.os.Bundle;
  13. import android.view.SurfaceView;
  14. import android.view.View;
  15. import android.widget.ImageView;
  16. import android.widget.TextView;
  17. public class testCamera extends Activity {
  18. /** Called when the activity is first created. */
  19. private SurfaceView sfvCamera;
  20. private SFHCamera sfhCamera;
  21. private ImageView imgView;
  22. private View centerView;
  23. private TextView txtScanResult;
  24. private Timer mTimer;
  25. private MyTimerTask mTimerTask;
  26. // 按照标准HVGA
  27. final static int width = 480;
  28. final static int height = 320;
  29. int dstLeft, dstTop, dstWidth, dstHeight;
  30. @Override
  31. public void onCreate(Bundle savedInstanceState) {
  32. super.onCreate(savedInstanceState);
  33. setContentView(R.layout.main);
  34. this.setTitle("Android条码/二维码识别Demo-----hellogv");
  35. imgView = (ImageView) this.findViewById(R.id.ImageView01);
  36. centerView = (View) this.findViewById(R.id.centerView);
  37. sfvCamera = (SurfaceView) this.findViewById(R.id.sfvCamera);
  38. sfhCamera = new SFHCamera(sfvCamera.getHolder(), width, height,
  39. previewCallback);
  40. txtScanResult=(TextView)this.findViewById(R.id.txtScanResult);
  41. // 初始化定时器
  42. mTimer = new Timer();
  43. mTimerTask = new MyTimerTask();
  44. mTimer.schedule(mTimerTask, 0, 80);
  45. }
  46. class MyTimerTask extends TimerTask {
  47. @Override
  48. public void run() {
  49. if (dstLeft == 0) {//只赋值一次
  50. dstLeft = centerView.getLeft() * width
  51. / getWindowManager().getDefaultDisplay().getWidth();
  52. dstTop = centerView.getTop() * height
  53. / getWindowManager().getDefaultDisplay().getHeight();
  54. dstWidth = (centerView.getRight() - centerView.getLeft())* width
  55. / getWindowManager().getDefaultDisplay().getWidth();
  56. dstHeight = (centerView.getBottom() - centerView.getTop())* height
  57. / getWindowManager().getDefaultDisplay().getHeight();
  58. }
  59. sfhCamera.AutoFocusAndPreviewCallback();
  60. }
  61. }
  62. /**
  63. * 自动对焦后输出图片
  64. */
  65. private Camera.PreviewCallback previewCallback = new Camera.PreviewCallback() {
  66. @Override
  67. public void onPreviewFrame(byte[] data, Camera arg1) {
  68. //取得指定范围的帧的数据
  69. PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource(
  70. data, width, height, dstLeft, dstTop, dstWidth, dstHeight);
  71. //取得灰度图
  72. Bitmap mBitmap = source.renderCroppedGreyscaleBitmap();
  73. //显示灰度图
  74. imgView.setImageBitmap(mBitmap);
  75. BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
  76. MultiFormatReader reader = new MultiFormatReader();
  77. try {
  78. Result result = reader.decode(bitmap);
  79. String strResult = "BarcodeFormat:"
  80. + result.getBarcodeFormat().toString() + " text:"
  81. + result.getText();
  82. txtScanResult.setText(strResult);
  83. } catch (Exception e) {
  84. txtScanResult.setText("Scanning");
  85. }
  86. }
  87. };
  88. }
package com.testCamera; import java.util.Timer; import java.util.TimerTask; import com.google.zxing.BinaryBitmap; import com.google.zxing.MultiFormatReader; import com.google.zxing.Result; import com.google.zxing.Android.PlanarYUVLuminanceSource; import com.google.zxing.common.HybridBinarizer; import android.app.Activity; import android.graphics.Bitmap; import android.hardware.Camera; import android.os.Bundle; import android.view.SurfaceView; import android.view.View; import android.widget.ImageView; import android.widget.TextView; public class testCamera extends Activity { /** Called when the activity is first created. */ private SurfaceView sfvCamera; private SFHCamera sfhCamera; private ImageView imgView; private View centerView; private TextView txtScanResult; private Timer mTimer; private MyTimerTask mTimerTask; // 按照标准HVGA final static int width = 480; final static int height = 320; int dstLeft, dstTop, dstWidth, dstHeight; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); this.setTitle("Android条码/二维码识别Demo-----hellogv"); imgView = (ImageView) this.findViewById(R.id.ImageView01); centerView = (View) this.findViewById(R.id.centerView); sfvCamera = (SurfaceView) this.findViewById(R.id.sfvCamera); sfhCamera = new SFHCamera(sfvCamera.getHolder(), width, height, previewCallback); txtScanResult=(TextView)this.findViewById(R.id.txtScanResult); // 初始化定时器 mTimer = new Timer(); mTimerTask = new MyTimerTask(); mTimer.schedule(mTimerTask, 0, 80); } class MyTimerTask extends TimerTask { @Override public void run() { if (dstLeft == 0) {//只赋值一次 dstLeft = centerView.getLeft() * width / getWindowManager().getDefaultDisplay().getWidth(); dstTop = centerView.getTop() * height / getWindowManager().getDefaultDisplay().getHeight(); dstWidth = (centerView.getRight() - centerView.getLeft())* width / getWindowManager().getDefaultDisplay().getWidth(); dstHeight = (centerView.getBottom() - centerView.getTop())* height / getWindowManager().getDefaultDisplay().getHeight(); } sfhCamera.AutoFocusAndPreviewCallback(); } } /** * 自动对焦后输出图片 */ private Camera.PreviewCallback previewCallback = new Camera.PreviewCallback() { @Override public void onPreviewFrame(byte[] data, Camera arg1) { //取得指定范围的帧的数据 PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource( data, width, height, dstLeft, dstTop, dstWidth, dstHeight); //取得灰度图 Bitmap mBitmap = source.renderCroppedGreyscaleBitmap(); //显示灰度图 imgView.setImageBitmap(mBitmap); BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source)); MultiFormatReader reader = new MultiFormatReader(); try { Result result = reader.decode(bitmap); String strResult = "BarcodeFormat:" + result.getBarcodeFormat().toString() + " text:" + result.getText(); txtScanResult.setText(strResult); } catch (Exception e) { txtScanResult.setText("Scanning"); } } }; }

SFHCamera.java是Camera控制类,源码如下:

[java] view plain copy print ?
  1. package com.testCamera;
  2. import java.io.IOException;
  3. import android.graphics.PixelFormat;
  4. import android.hardware.Camera;
  5. import android.util.Log;
  6. import android.view.SurfaceHolder;
  7. public class SFHCamera implements SurfaceHolder.Callback{
  8. private SurfaceHolder holder = null;
  9. private Camera mCamera;
  10. private int width,height;
  11. private Camera.PreviewCallback previewCallback;
  12. public SFHCamera(SurfaceHolder holder,int w,int h,Camera.PreviewCallback previewCallback) {
  13. this.holder = holder;
  14. this.holder.addCallback(this);
  15. this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
  16. width=w;
  17. height=h;
  18. this.previewCallback=previewCallback;
  19. }
  20. @Override
  21. public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
  22. Camera.Parameters parameters = mCamera.getParameters();
  23. parameters.setPreviewSize(width, height);//设置尺寸
  24. parameters.setPictureFormat(PixelFormat.JPEG);
  25. mCamera.setParameters(parameters);
  26. mCamera.startPreview();//开始预览
  27. Log.e("Camera","surfaceChanged");
  28. }
  29. @Override
  30. public void surfaceCreated(SurfaceHolder arg0) {
  31. mCamera = Camera.open();//启动服务
  32. try {
  33. mCamera.setPreviewDisplay(holder);//设置预览
  34. Log.e("Camera","surfaceCreated");
  35. } catch (IOException e) {
  36. mCamera.release();//释放
  37. mCamera = null;
  38. }
  39. }
  40. @Override
  41. public void surfaceDestroyed(SurfaceHolder arg0) {
  42. mCamera.setPreviewCallback(null);
  43. mCamera.stopPreview();//停止预览
  44. mCamera = null;
  45. Log.e("Camera","surfaceDestroyed");
  46. }
  47. /**
  48. * 自动对焦并回调Camera.PreviewCallback
  49. */
  50. public void AutoFocusAndPreviewCallback()
  51. {
  52. if(mCamera!=null)
  53. mCamera.autoFocus(mAutoFocusCallBack);
  54. }
  55. /**
  56. * 自动对焦
  57. */
  58. private Camera.AutoFocusCallback mAutoFocusCallBack = new Camera.AutoFocusCallback() {
  59. @Override
  60. public void onAutoFocus(boolean success, Camera camera) {
  61. if (success) { //对焦成功,回调Camera.PreviewCallback
  62. mCamera.setOneShotPreviewCallback(previewCallback);
  63. }
  64. }
  65. };
  66. }
package com.testCamera; import java.io.IOException; import android.graphics.PixelFormat; import android.hardware.Camera; import android.util.Log; import android.view.SurfaceHolder; public class SFHCamera implements SurfaceHolder.Callback{ private SurfaceHolder holder = null; private Camera mCamera; private int width,height; private Camera.PreviewCallback previewCallback; public SFHCamera(SurfaceHolder holder,int w,int h,Camera.PreviewCallback previewCallback) { this.holder = holder; this.holder.addCallback(this); this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); width=w; height=h; this.previewCallback=previewCallback; } @Override public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) { Camera.Parameters parameters = mCamera.getParameters(); parameters.setPreviewSize(width, height);//设置尺寸 parameters.setPictureFormat(PixelFormat.JPEG); mCamera.setParameters(parameters); mCamera.startPreview();//开始预览 Log.e("Camera","surfaceChanged"); } @Override public void surfaceCreated(SurfaceHolder arg0) { mCamera = Camera.open();//启动服务 try { mCamera.setPreviewDisplay(holder);//设置预览 Log.e("Camera","surfaceCreated"); } catch (IOException e) { mCamera.release();//释放 mCamera = null; } } @Override public void surfaceDestroyed(SurfaceHolder arg0) { mCamera.setPreviewCallback(null); mCamera.stopPreview();//停止预览 mCamera = null; Log.e("Camera","surfaceDestroyed"); } /** * 自动对焦并回调Camera.PreviewCallback */ public void AutoFocusAndPreviewCallback() { if(mCamera!=null) mCamera.autoFocus(mAutoFocusCallBack); } /** * 自动对焦 */ private Camera.AutoFocusCallback mAutoFocusCallBack = new Camera.AutoFocusCallback() { @Override public void onAutoFocus(boolean success, Camera camera) { if (success) { //对焦成功,回调Camera.PreviewCallback mCamera.setOneShotPreviewCallback(previewCallback); } } }; }

其中testCamera.java的Camera.PreviewCallback previewCallback 是整个程序的逻辑核心,作为回调函数给SFHCamera.java的内部Camera类调用。

你可能感兴趣的:(在Android上使用ZXing识别条形码/二维码)