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);
为
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

package com.AndroidOrientation;import android.app.Activity;
import android.content.Context;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.OrientationEventListener;
import android.widget.TextView;
import android.widget.Toast;
public class AndroidOrientation extends Activity{
TextView orientation;
MyOrientationEventListener myOrientationEventListener;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);
setContentView(R.layout.main);
orientation = (TextView)findViewById(R.id.orientation); myOrientationEventListener = new MyOrientationEventListener(this, SensorManager.SENSOR_DELAY_NORMAL);
if (myOrientationEventListener.canDetectOrientation()){ myOrientationEventListener.enable();
}else{
Toast.makeText(AndroidOrientation.this, "Can't DetectOrientation!", Toast.LENGTH_LONG).show();
} }
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
myOrientationEventListener.disable();}
class MyOrientationEventListener extends OrientationEventListener{ public MyOrientationEventListener(Context context, int rate) {
super(context, rate);
// TODO Auto-generated constructor stub }
@Override public void onOrientationChanged(int arg0) {
// TODO Auto-generated method stub
orientation.setText(String.valueOf(arg0));
}
}}

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