Android Zxing修改为竖屏扫描，和连续扫描问题

1.在清单配置文件当中

android:screenOrientation="landscape"修改为android:screenOrientation="portrait"

2.修改CameraManager类，在getFramingRectInPreview方法中

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.修改CameraConfigurationManager类，在initFromCameraParameters方法中

在

Log.d(TAG, "Screen resolution: " + screenResolution);

这句代码后面加入下面的代码，防止修改为竖屏之后图像拉伸的问题

// 解决竖屏后图像拉伸问题
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;
}
cameraResolution = getCameraResolution(parameters,
screenResolutionForCamera);

然后再setDesiredCameraParameters方法当中加入一句代码

setDisplayOrientation(camera, 90);//把摄像头视角旋转90度

然后再这个类里面加入上面的方法

protected void setDisplayOrientation(Camera camera, int angle) {
Method downPolymorphic;
try {
downPolymorphic = camera.getClass().getMethod(
"setDisplayOrientation", new Class[] { int.class });
if (downPolymorphic != null)
downPolymorphic.invoke(camera, new Object[] { angle });
} catch (Exception e1) {
e1.printStackTrace();
}
}

4.修改DecodeHandler类文件，在decode(byte[] data, int width, int height)方法中

在buildLuminanceSource方法调用前面加入下面的代码

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

然后注释掉原来的buildLuminanceSource这行调用代码。

到这里竖屏代码就修改完成了，如果想修改扫描框的大小，可以去CameraManager这个类当中，修改这些常量就可以了

private static final int MIN_FRAME_WIDTH = 240;
private static final int MIN_FRAME_HEIGHT = 240;
private static final int MAX_FRAME_WIDTH = 480;
private static final int MAX_FRAME_HEIGHT = 360;

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Zxing扫描一次二维码或条形码完成之后，想要继续扫描的话，就需要重新进入这个扫描页面，很麻烦，想要实现连续扫描的话，在CaptureActivity类当中加入下面这个方法:

/**
* 使Zxing能够继续扫描
*/
public void continuePreview() {
if (handler != null) {
handler.restartPreviewAndDecode();
}
}

这里的handler就是CaptureActivityHandler类的实例，在合适的地方调用这个方法就可以连续的进行二维码的扫描了。