• [转]android条形码编解码


    本文转自:http://daixj110.iteye.com/blog/1459173

    对条形码的编解码可以用barcode库和zxing库,但对于android ,barcode库中的BufferedImage不能使用,我所看到的用得较多的是zxing库,地址在http://code.google.com/p/zxing/ 里面有库的源码与几种平台的例子。里面的例子只支持横屏模式下,要支持竖屏得对其进行修改。步骤如下:

    1.在DecodeHandler.java中,修改decode方法
    PlanarYUVLuminanceSource source = CameraManager.get().buildLuminanceSource(data, width, height);

    byte[] rotatedData = new byte[data.length];
    for (int y = 0; y < height; y++) {
    for (int x = 0; x < width; x++)
    rotatedData[x * height + height - y - 1] = data[x + y * width];
    }
    int tmp = width; // Here we are swapping, that's the difference to #11
    width = height;
    height = tmp;

    PlanarYUVLuminanceSource source = CameraManager.get().buildLuminanceSource(rotatedData, width, height);

    2.在CameraManager.java中,注释代码:
    // rect.left = rect.left * cameraResolution.x / screenResolution.x;
    // rect.right = rect.right * cameraResolution.x / screenResolution.x;
    // rect.top = rect.top * cameraResolution.y / screenResolution.y;
    // rect.bottom = rect.bottom * cameraResolution.y / screenResolution.y;
    修改为
    rect.left = rect.left * cameraResolution.y / screenResolution.x;
    rect.right = rect.right * cameraResolution.y / screenResolution.x;
    rect.top = rect.top * cameraResolution.x / screenResolution.y;
    rect.bottom = rect.bottom * cameraResolution.x / screenResolution.y;

    3.在CameraConfigurationManager.java中,在setDesiredCameraParameters方法中添加一句
    camera.setDisplayOrientation(90);

    4.在AndroidManifest.xml中,把Activity的属性android:screenOrientation="landscape"
    改为
    android:screenOrientation="portrait"

    编译运行即可!

    参考:

    http://code.google.com/p/zxing/issues/detail?id=178#c46

    代码:

    https://github.com/pplante/zxing-android

    解码实际是对摄像头获得的数据的yuv数据进行解码

    注:setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); 设置后或者在mainfest配置文件中landscape后,onconfigruationChanged不被调用,所以不能用来判断横竖屏

    对于解码要支持横竖屏得涉及方向的判断,这儿有几篇文章可以参考:

    yuv数据的转换

    http://chenweihuacwh.iteye.com/blog/571223

    通过senser获得屏幕旋转

    http://blog.csdn.net/a345017062/article/details/6592527

    传感器设计的指南针

    http://blog.csdn.net/tinya0913/article/details/6057637

    通过orientationeventListener判断手机横竖指向

    http://androidbiancheng.blogspot.jp/2011/05/orientationeventlistener.html

    Java代码 复制代码 收藏代码
    1. package com.AndroidOrientation;import android.app.Activity;
    2. import android.content.Context;
    3. import android.hardware.SensorManager;
    4. import android.os.Bundle;
    5. import android.view.OrientationEventListener;
    6. import android.widget.TextView;
    7. import android.widget.Toast;
    8. public class AndroidOrientation extends Activity{
    9. TextView orientation;
    10. MyOrientationEventListener myOrientationEventListener;
    11. /** Called when the activity is first created. */
    12. @Override
    13. public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);
    14. setContentView(R.layout.main);
    15. orientation = (TextView)findViewById(R.id.orientation); myOrientationEventListener = new MyOrientationEventListener(this, SensorManager.SENSOR_DELAY_NORMAL);
    16. if (myOrientationEventListener.canDetectOrientation()){ myOrientationEventListener.enable();
    17. }else{
    18. Toast.makeText(AndroidOrientation.this, "Can't DetectOrientation!", Toast.LENGTH_LONG).show();
    19. } }
    20. @Override
    21. protected void onDestroy() {
    22. // TODO Auto-generated method stub
    23. super.onDestroy();
    24. myOrientationEventListener.disable();}
    25. class MyOrientationEventListener extends OrientationEventListener{ public MyOrientationEventListener(Context context, int rate) {
    26. super(context, rate);
    27. // TODO Auto-generated constructor stub }
    28. @Override public void onOrientationChanged(int arg0) {
    29. // TODO Auto-generated method stub
    30. orientation.setText(String.valueOf(arg0));
    31. }
    32. }}
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  • 原文地址:https://www.cnblogs.com/freeliver54/p/2564364.html
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