利用开源ZXing项目实现条形码和二维码扫描识别 —— Android端

浏览数：29 / 时间：2015年06月11日

前言

首先使用ZXing项目前我们需要对其进行简化，因为开源的ZXing项目中Android实现里面有太多多余的东西了，得对其进行简化，并且原始的ZXing项目扫描框并不美观所以也要对其进行自定义美化。

简化

在开始前大致介绍一下简化ZXing需要用到各个包、类的职责。

CaptureActivity。这个是启动Activity 也就是扫描器（如果是第一安装，它还会跳转到帮助界面）。
CaptureActivityHandler 解码处理类，负责调用另外的线程进行解码。
DecodeThread 解码的线程。
com.google.zxing.client.android.camera 包，摄像头控制包。
ViewfinderView 自定义的View，就是我们看见的拍摄时中间的框框了。

详细简化过程参考博文“http://www.cnblogs.com/keyindex/archive/2011/06/08/2074900.html”

自定义扫描框

自定义扫描框需要修改ViewfinderView自定义的View类。绘制窗体方法在onDraw(Canvas canvas)方法中。

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@Override
    public 
void onDraw(Canvas canvas) {
        Rect frame = CameraManager.get().getFramingRect();
        if 
(frame == null) {
            return;
        }
 
        // 初始化中间线滑动的最上边和最下边
        if 
(!isFirst) {
            isFirst = true;
            slideTop = frame.top;
            slideBottom = frame.bottom;
        }
 
        int 
width = canvas.getWidth();
        int 
height = canvas.getHeight();
 
        // Draw the exterior (i.e. outside the framing rect) darkened
        paint.setColor(resultBitmap != null 
? resultColor : maskColor);
        canvas.drawRect(0, 0, width, frame.top, paint);
        canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
        canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1,
                paint);
        canvas.drawRect(0, frame.bottom + 1, width, height, paint);
 
        if 
(resultBitmap != null) {
            // Draw the opaque result bitmap over the scanning rectangle
            paint.setAlpha(OPAQUE);
            canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);
        } else 
{
 
            // 画扫描框
            paint.setColor(frameColor);
            canvas.drawRect(frame.left, frame.top, frame.right + 1,
                    frame.top + 2, paint);
            canvas.drawRect(frame.left, frame.top + 2, frame.left + 2,
                    frame.bottom - 1, paint);
            canvas.drawRect(frame.right - 1, frame.top, frame.right + 1,
                    frame.bottom - 1, paint);
            canvas.drawRect(frame.left, frame.bottom - 1, frame.right + 1,
                    frame.bottom + 1, paint);
 
            paint.setColor(laserColor);
             
            //画扫描框边上的角，总共8个部分
            canvas.drawRect(frame.left, frame.top, frame.left + ScreenRate,
                    frame.top + CORNER_WIDTH, paint);
            canvas.drawRect(frame.left, frame.top, frame.left + CORNER_WIDTH, frame.top
                    + ScreenRate, paint);
            canvas.drawRect(frame.right - ScreenRate, frame.top, frame.right,
                    frame.top + CORNER_WIDTH, paint);
            canvas.drawRect(frame.right - CORNER_WIDTH, frame.top, frame.right, frame.top
                    + ScreenRate, paint);
            canvas.drawRect(frame.left, frame.bottom - CORNER_WIDTH, frame.left
                    + ScreenRate, frame.bottom, paint);
            canvas.drawRect(frame.left, frame.bottom - ScreenRate,
                    frame.left + CORNER_WIDTH, frame.bottom, paint);
            canvas.drawRect(frame.right - ScreenRate, frame.bottom - CORNER_WIDTH,
                    frame.right, frame.bottom, paint);
            canvas.drawRect(frame.right - CORNER_WIDTH, frame.bottom - ScreenRate,
                    frame.right, frame.bottom, paint);
             
             
            paint.setAlpha(SCANNER_ALPHA[scannerAlpha]);
            scannerAlpha = (scannerAlpha + 1) % SCANNER_ALPHA.length;
 
            //绘制中间的线,每次刷新界面，中间的线往下移动SPEEN_DISTANCE
            slideTop += SPEEN_DISTANCE;
            if(slideTop >= frame.bottom){
                slideTop = frame.top;
            }
            canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop - MIDDLE_LINE_WIDTH/2, frame.right - MIDDLE_LINE_PADDING,slideTop + MIDDLE_LINE_WIDTH/2, paint);
             
 
            Collection<ResultPoint> currentPossible = possibleResultPoints;
            Collection<ResultPoint> currentLast = lastPossibleResultPoints;
            if 
(currentPossible.isEmpty()) {
                lastPossibleResultPoints = null;
            } else 
{
                possibleResultPoints = new 
HashSet<ResultPoint>(5);
                lastPossibleResultPoints = currentPossible;
                paint.setAlpha(OPAQUE);
                paint.setColor(resultPointColor);
                for 
(ResultPoint point : currentPossible) {
                    canvas.drawCircle(frame.left + point.getX(), frame.top
                            + point.getY(), 6.0f, paint);
                }
            }
            if 
(currentLast != null) {
                paint.setAlpha(OPAQUE / 2);
                paint.setColor(resultPointColor);
                for 
(ResultPoint point : currentLast) {
                    canvas.drawCircle(frame.left + point.getX(), frame.top
                            + point.getY(), 3.0f, paint);
                }
            }
             
            postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,
                    frame.right, frame.bottom);
        }
    }