android - 更改 zxing 扫描仪矩形尺寸

Question

当我尝试更改 zxing 二维码阅读器的扫描仪矩形的尺寸时，它会更改它，但它会停止扫描二维码。我尝试按照以下方法更改矩形的尺寸:

1. onDraw() ViewFinderView.java 函数，我调用了frame.set(0,0,300,300)

2. cameraManager.setManualFramingRect(300,300);

两者都改变​​了矩形的尺寸，但随后它停止扫描代码。请帮帮我..提前致谢..

Answer 1

如果您将 ZXing 用作库并且无法修改源代码

您可以创建自定义类来定义所有相机预览行为，包括移除红线、使其变为正方形、添加自定义 Logo 、扫描二维码。您所要做的就是在您的项目中创建以下类

public class CustomZXingScannerView extends View implements IViewFinder {
    private static final String TAG = "ViewFinderView";

    private Rect mFramingRect;

    private static final float PORTRAIT_WIDTH_RATIO = 6f/8;
    private static final float PORTRAIT_WIDTH_HEIGHT_RATIO = 0.75f;

    private static final float LANDSCAPE_HEIGHT_RATIO = 5f/8;
    private static final float LANDSCAPE_WIDTH_HEIGHT_RATIO = 1.4f;
    private static final int MIN_DIMENSION_DIFF = 50;

    private static final float SQUARE_DIMENSION_RATIO = 5f/8;

    private static final int[] SCANNER_ALPHA = {0, 64, 128, 192, 255, 192, 128, 64};
    private int scannerAlpha;
    private static final int POINT_SIZE = 10;
    private static final long ANIMATION_DELAY = 80l;

    private final int mDefaultLaserColor = getResources().getColor(R.color.viewfinder_laser);
    private final int mDefaultMaskColor = getResources().getColor(R.color.viewfinder_mask);
    private final int mDefaultBorderColor = getResources().getColor(R.color.viewfinder_border);
    private final int mDefaultBorderStrokeWidth = getResources().getInteger(R.integer.viewfinder_border_width);
    private final int mDefaultBorderLineLength = getResources().getInteger(R.integer.viewfinder_border_length);

    protected Paint mLaserPaint;
    protected Paint mFinderMaskPaint;
    protected Paint mBorderPaint;
    protected int mBorderLineLength;
    protected boolean mSquareViewFinder;

    public CustomZXingScannerView(Context context) {
        super(context);
        init();
    }

    public CustomZXingScannerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        //set up laser paint
        mLaserPaint = new Paint();
        mLaserPaint.setColor(mDefaultLaserColor);
        mLaserPaint.setStyle(Paint.Style.FILL);

        //finder mask paint
        mFinderMaskPaint = new Paint();
        mFinderMaskPaint.setColor(mDefaultMaskColor);

        //border paint
        mBorderPaint = new Paint();
        mBorderPaint.setColor(mDefaultBorderColor);
        mBorderPaint.setStyle(Paint.Style.STROKE);
        mBorderPaint.setStrokeWidth(mDefaultBorderStrokeWidth);

        mBorderLineLength = mDefaultBorderLineLength;
    }

    public void setLaserColor(int laserColor) {
        mLaserPaint.setColor(laserColor);
    }
    public void setMaskColor(int maskColor) {
        mFinderMaskPaint.setColor(maskColor);
    }
    public void setBorderColor(int borderColor) {
        mBorderPaint.setColor(borderColor);
    }
    public void setBorderStrokeWidth(int borderStrokeWidth) {
        mBorderPaint.setStrokeWidth(borderStrokeWidth);
    }
    public void setBorderLineLength(int borderLineLength) {
        mBorderLineLength = borderLineLength;
    }

    // TODO: Need a better way to configure this. Revisit when working on 2.0
    public void setSquareViewFinder(boolean set) {
        mSquareViewFinder = set;
    }

    public void setupViewFinder() {
        updateFramingRect();
        invalidate();
    }

    public Rect getFramingRect() {
        return mFramingRect;
    }

    @Override
    public void onDraw(Canvas canvas) {
        if(getFramingRect() == null) {
            return;
        }

        drawViewFinderMask(canvas);
        drawViewFinderBorder(canvas);
        drawLaser(canvas);
    }

    public void drawViewFinderMask(Canvas canvas) {
        int width = canvas.getWidth();
        int height = canvas.getHeight();
        Rect framingRect = getFramingRect();

        canvas.drawRect(0, 0, width, framingRect.top, mFinderMaskPaint);
        canvas.drawRect(0, framingRect.top, framingRect.left, framingRect.bottom + 1, mFinderMaskPaint);
        canvas.drawRect(framingRect.right + 1, framingRect.top, width, framingRect.bottom + 1, mFinderMaskPaint);
        canvas.drawRect(0, framingRect.bottom + 1, width, height, mFinderMaskPaint);
    }

    public void drawViewFinderBorder(Canvas canvas) {
        Rect framingRect = getFramingRect();

        canvas.drawLine(framingRect.left - 1, framingRect.top - 1, framingRect.left - 1, framingRect.top - 1 + mBorderLineLength, mBorderPaint);
        canvas.drawLine(framingRect.left - 1, framingRect.top - 1, framingRect.left - 1 + mBorderLineLength, framingRect.top - 1, mBorderPaint);

        canvas.drawLine(framingRect.left - 1, framingRect.bottom + 1, framingRect.left - 1, framingRect.bottom + 1 - mBorderLineLength, mBorderPaint);
        canvas.drawLine(framingRect.left - 1, framingRect.bottom + 1, framingRect.left - 1 + mBorderLineLength, framingRect.bottom + 1, mBorderPaint);

        canvas.drawLine(framingRect.right + 1, framingRect.top - 1, framingRect.right + 1, framingRect.top - 1 + mBorderLineLength, mBorderPaint);
        canvas.drawLine(framingRect.right + 1, framingRect.top - 1, framingRect.right + 1 - mBorderLineLength, framingRect.top - 1, mBorderPaint);

        canvas.drawLine(framingRect.right + 1, framingRect.bottom + 1, framingRect.right + 1, framingRect.bottom + 1 - mBorderLineLength, mBorderPaint);
        canvas.drawLine(framingRect.right + 1, framingRect.bottom + 1, framingRect.right + 1 - mBorderLineLength, framingRect.bottom + 1, mBorderPaint);
    }

    public void drawLaser(Canvas canvas) {
        Rect framingRect = getFramingRect();

        // Draw a red "laser scanner" line through the middle to show decoding is active
        mLaserPaint.setAlpha(SCANNER_ALPHA[scannerAlpha]);
        scannerAlpha = (scannerAlpha + 1) % SCANNER_ALPHA.length;
        int middle = framingRect.height() / 2 + framingRect.top;
        canvas.drawRect(framingRect.left + 2, middle - 1, framingRect.right - 1, middle + 2, mLaserPaint);

        postInvalidateDelayed(ANIMATION_DELAY,
                framingRect.left - POINT_SIZE,
                framingRect.top - POINT_SIZE,
                framingRect.right + POINT_SIZE,
                framingRect.bottom + POINT_SIZE);
    }

    @Override
    protected void onSizeChanged(int xNew, int yNew, int xOld, int yOld) {
        updateFramingRect();
    }

    public synchronized void updateFramingRect() {
        Point viewResolution = new Point(getWidth(), getHeight());
        int width;
        int height;
        int orientation = DisplayUtils.getScreenOrientation(getContext());

        if(mSquareViewFinder) {
            if(orientation != Configuration.ORIENTATION_PORTRAIT) {
                height = (int) (getHeight() * SQUARE_DIMENSION_RATIO);
                width = height;
            } else {
                width = (int) (getWidth() * SQUARE_DIMENSION_RATIO);
                height = width;
            }
        } else {
            if(orientation != Configuration.ORIENTATION_PORTRAIT) {
                height = (int) (getHeight() * LANDSCAPE_HEIGHT_RATIO);
                width = (int) (LANDSCAPE_WIDTH_HEIGHT_RATIO * height);
            } else {
                width = (int) (getWidth() * PORTRAIT_WIDTH_RATIO);
                height = (int) (PORTRAIT_WIDTH_HEIGHT_RATIO * width);
            }
        }

        if(width > getWidth()) {
            width = getWidth() - MIN_DIMENSION_DIFF;
        }

        if(height > getHeight()) {
            height = getHeight() - MIN_DIMENSION_DIFF;
        }

        int leftOffset = (viewResolution.x - width) / 2;
        int topOffset = (viewResolution.y - height) / 2;
        mFramingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height);
    }
}

您可以根据需要修改任何属性或方法。

之后，在创建 ZXing Activity 的 Activity 中，修改 onCreate 方法以使用您刚刚复制和粘贴的类:

public class SimpleScannerActivity extends AppCompatActivity implements ZXingScannerView.ResultHandler {

    private static final String TAG = "INDIGO";
    private ZXingScannerView mScannerView;

    public static String SCANNER_GIVE_RESULT = "SCANNER_GIVE_RESULT";
    public static String SCANNER_RESULT = "SCANNER_RESULT";

    private boolean returnResult;

    @Override
    public void onCreate(Bundle state) {
        super.onCreate(state);
        mScannerView = new ZXingScannerView(this) {

            @Override
            protected IViewFinder createViewFinderView(Context context) {
                return new CustomZXingScannerView(context);
            }

        };    // Programmatically initialize the scanner view
        List<BarcodeFormat> formats = new ArrayList<>();
        formats.add(BarcodeFormat.QR_CODE);
        setContentView(mScannerView);                // Set the scanner view as the content view

        returnResult = getIntent().getBooleanExtra(SCANNER_GIVE_RESULT, false);
    }