Android開源二維碼識別專案zxing橫屏改為豎屏識別解決方案
在網上找了很多方法，但最後都有問題，自己除錯了好幾個小時，最後終於完美解決了豎屏識別。
首先你需要有zxing專案的簡化版程式碼。
使用簡化版可以免去許多不必要的程式碼，方便學習研究，更好定位核心功能。
如果你除錯成功後，就可以著手修改將其變為豎屏識別了。
第1步：
在AndroidManifest中將CaptureActivity的screenOrientation屬性做如下修改：
android:screenOrientation="portrait"第2步：
我們要把攝像頭預覽景調為豎向
CameraConfigurationManager類中的setDesiredCameraParameters()方法中新增如下程式碼：
setDisplayOrientation(camera, 90);
然後在CameraConfigurationManager類的最後新增setDisplayOrientation()方法:
/*改變照相機成像的方向的方法*/ protected void setDisplayOrientation(Camera camera, int angle) { Method downPolymorphic = null;try {
downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new
if (downPolymorphic != null)
downPolymorphic.invoke(camera, new Object[]{angle});
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace(); } }
最後在CameraConfigurationManager中的initFromCameraParameters()方法的Log.d(TAG, "Screen resolution: " + screenResolution);句後面新增如下程式碼，這段程式碼是為了解決攝像頭豎過來後圖像拉伸的問題：
//為豎屏新增Point screenResolutionForCamera = new Point();
screenResolutionForCamera.x = screenResolution.x;
screenResolutionForCamera.y = screenResolution.y;
if (screenResolution.x < screenResolution.y) {
screenResolutionForCamera.x = screenResolution.y;
screenResolutionForCamera.y = screenResolution.x;
} // 下句第二引數要根據豎屏修改
cameraResolution = getCameraResolution(parameters, screenResolutionForCamera);
第3步:
CameranManager類中getFramingRectInPreview()方法將：
// 下面為橫屏模式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;
替換為：
/// 下面為豎屏模式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;
第4步：
PlanarYUVLuminanceSource類中的getRow()方法為識別條形碼部分，
getMatrix()方法為識別二維碼部分
renderCroppedGreyscaleBitmap()方法為生成獲取的碼圖部分
將getRow()中的：
int offset = (y + top) * dataWidth + left;getMatrix()中的：
int inputOffset = top * dataWidth + left;inputOffset += dataWidth;
renderCroppedGreyscaleBitmap()中的：
int inputOffset = top * dataWidth + left;inputOffset += dataWidth;
這些語句中dataWidth全部替換為dataHeight
同時將PlanarYUVLuminanceSource構造方法中：
if (left + width > dataWidth || top + height > dataHeight) { thrownew IllegalArgumentException("Crop rectangle does not fit within image data."); }dataWidth與dateHeight中互換位置即可。
此時，你的程式豎屏識別碼圖應該沒有任何問題了。至於取景框的樣式，大家可以在自定義的ViewfinderView中修改成自己喜歡的樣式。
http://407827531.iteye.com/blog/1488676
解決方法：
1.在DecodeHandler.java中，修改decode方法
PlanarYUVLuminanceSource source = CameraManager.get().buildLuminanceSource(data, width, height);
為
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，註釋程式碼：
// 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;
修改為
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方法中新增一句
camera.setDisplayOrientation(90);
4.在AndroidManifest.xml中，把Activity的屬性android:screenOrientation="landscape"
改為
android:screenOrientation="portrait"
編譯執行即可！
參考：
http://code.google.com/p/zxing/issues/detail?id=178#c46
程式碼：
https://github.com/pplante/zxing-android
按照以上做法，可以實現。
使用簡化版可以免去許多不必要的程式碼，方便學習研究，更好定位核心功能。
如果你除錯成功後，就可以著手修改將其變為豎屏識別了。
第1步：
在AndroidManifest中將CaptureActivity的screenOrientation屬性做如下修改：
android:screenOrientation="portrait"
第2步：
我們要把攝像頭預覽景調為豎向
CameraConfigurationManager類中的setDesiredCameraParameters()方法中新增如下程式碼：
// 使攝像頭旋轉90度 setDisplayOrientation(camera, 90);
然後在CameraConfigurationManager類的最後新增setDisplayOrientation()方法:
/*改變照相機成像的方向的方法*/ protected void setDisplayOrientation(Camera camera, int angle) { Method downPolymorphic = null; try { downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new Class[] { int.class }); if (downPolymorphic != null) downPolymorphic.invoke(camera, new Object[]{angle}); } catch (NoSuchMethodException e) { e.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } }
最後在CameraConfigurationManager中的initFromCameraParameters()方法的Log.d(TAG, "Screen resolution: " + screenResolution);句後面新增如下程式碼，這段程式碼是為了解決攝像頭豎過來後圖像拉伸的問題：
//為豎屏新增 Point screenResolutionForCamera = new Point(); screenResolutionForCamera.x = screenResolution.x; screenResolutionForCamera.y = screenResolution.y; if (screenResolution.x < screenResolution.y) { screenResolutionForCamera.x = screenResolution.y; screenResolutionForCamera.y = screenResolution.x; } // 下句第二引數要根據豎屏修改 cameraResolution = getCameraResolution(parameters, screenResolutionForCamera);
第3步:
CameranManager類中getFramingRectInPreview()方法將：
// 下面為橫屏模式 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;
替換為：
// 下面為豎屏模式 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;
第4步：
PlanarYUVLuminanceSource類中的getRow()方法為識別條形碼部分，
getMatrix()方法為識別二維碼部分
renderCroppedGreyscaleBitmap()方法為生成獲取的碼圖部分
將getRow()中的：
int offset = (y + top) * dataWidth + left;
getMatrix()中的：
int inputOffset = top * dataWidth + left;
inputOffset += dataWidth;
renderCroppedGreyscaleBitmap()中的：
int inputOffset = top * dataWidth + left;
inputOffset += dataWidth;
這些語句中dataWidth全部替換為dataHeight
同時將PlanarYUVLuminanceSource構造方法中：
if (left + width > dataWidth || top + height > dataHeight) { throw new IllegalArgumentException("Crop rectangle does not fit within image data."); }
dataWidth與dateHeight中互換位置即可。
此時，你的程式豎屏識別碼圖應該沒有任何問題了。至於取景框的樣式，大家可以在自定義的ViewfinderView中修改成自己喜歡的樣式。
——————————————————————————————
測試，可以豎屏，但是取景還是得橫著來。
解決方法：
1.在DecodeHandler.java中，修改decode方法
PlanarYUVLuminanceSource source = CameraManager.get().buildLuminanceSource(data, width, height);
為
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，註釋程式碼：
// 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;
修改為
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方法中新增一句
camera.setDisplayOrientation(90);
4.在AndroidManifest.xml中，把Activity的屬性android:screenOrientation="landscape"
改為
android:screenOrientation="portrait"
編譯執行即可！
參考：
http://code.google.com/p/zxing/issues/detail?id=178#c46
程式碼：
https://github.com/pplante/zxing-android
————————
按照下篇的解決方案，成功解決問題。
實現zxing多次掃描問題：
private void continuePreview()
{
SurfaceView surfaceView = (SurfaceView) findViewById(R.id.preview_view);
SurfaceHolder surfaceHolder = surfaceView.getHolder();
initCamera(surfaceHolder);
if (handler != null)
handler.restartPreviewAndDecode();
}
CaptureActivityHandler中restartPreviewAndDecode屬性由private 設定成public
——————————————————————————————
掃描二維碼圖片時候，正方形的二維碼圖片，顯示會發現變拉長、拉伸。
找著的解決途徑如下：
http://www.apkbus.com/android-94078-1-1.html
更改CameraConfigurationManager.java檔案
在 Log.d(TAG, "Screen resolution: " + screenResolution);這句之後增加
Point screenResolutionForCamera = new Point();
screenResolutionForCamera.x = screenResolution.x;
screenResolutionForCamera.y = screenResolution.y;
// preview size is always something like 480*320, other 320*480
if (screenResolution.x < screenResolution.y) {
screenResolutionForCamera.x = screenResolution.y;
screenResolutionForCamera.y = screenResolution.x;
}
再更改cameraResolution = getCameraResolution(parameters, screenResolution);為cameraResolution = getCameraResolution(parameters, screenResolutionForCamera);
PS:有時間一定要讀zxing原始碼的。