主要有三点：
1、界面绘制，包括4个边角、上下滚动的横线、在画布上添加文字
2、调整二维码扫描框的位置。
3、解决图片被压变形的问题。
1、界面绘制
ViewfinderView.java中onDraw()方法
@Overridepublic void onDraw(Canvas canvas) {// 中间的扫描框，你要修改扫描框的大小，去CameraManager里面修改Rect frame = CameraManager.get().getFramingRect();int top = frame.top;int left = frame.left;int right = frame.right;int bottom = frame.bottom;frame = new Rect(left , top, right , bottom );// 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;}// 获取屏幕的宽和高int width = canvas.getWidth();int height = canvas.getHeight();// 画出扫描框外面的阴影部分，共四个部分，扫描框的上面到屏幕上面，扫描框的下面到屏幕下面// 扫描框的左边面到屏幕左边，扫描框的右边到屏幕右边// Draw the exterior (i.e. outside the framing rect) darkenedpaint.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 rectanglepaint.setAlpha(OPAQUE);canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);} else {// 画扫描框边上的角，总共8个部分paint.setColor(Color.GREEN);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);//绘制中间的线,每次刷新界面，中间的线往下移动SPEEN_DISTANCEslideTop += SPEEN_DISTANCE;if(slideTop >= frame.bottom){slideTop = frame.top;}Rect lineRect = new Rect();lineRect.left = frame.left;lineRect.right = frame.right;lineRect.top = slideTop;lineRect.bottom = slideTop + 18;canvas.drawBitmap(((BitmapDrawable)(getResources().getDrawable(R.drawable.qrcode_scan_line))).getBitmap(), null, lineRect, paint);//画扫描框下面的字//paint.setColor(Color.WHITE);//paint.setTextSize(TEXT_SIZE * density);//paint.setAlpha(0x40);//paint.setTypeface(Typeface.create("System", Typeface.BOLD)); //String text = "将二维码放入框内, 即可自动扫描"; //float textWidth = paint.measureText(text); ////canvas.drawText(text, (width – textWidth)/2, (float) (frame.bottom + (float)TEXT_PADDING_TOP *density), 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);}}//只刷新扫描框的内容，其他地方不刷新postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,frame.right, frame.bottom);}}
2、调整位置
如果不设置全屏，扫描框的位置和取图的位置高度目测会有50px误差，
不全屏公式：((Y – 标题栏 – 状态栏)/2 – 扫描框高度)/2 = y轴坐标
只要不全屏：就会有误差，导致框中的二维码靠上或者远离二维码才会扫描成功
如果设置为全屏，就不会有误差，请了解内情的大神告知笔者，，想知道什么原因造成
CameraManager.java 中 getFramingRect()方法
public Rect getFramingRect() {Point screenResolution = configManager.getScreenResolution();if (framingRect == null) {if (camera == null) {return null;}/* 确定在固定比例分辨率下二维码扫描框的宽高*/int width = screenResolution.x * 3 / 4;if (width < MIN_FRAME_WIDTH) {width = MIN_FRAME_WIDTH;} else if (width > MAX_FRAME_WIDTH) {width = MAX_FRAME_WIDTH;}int height = screenResolution.y * 3 / 4;if (height < MIN_FRAME_HEIGHT) {height = MIN_FRAME_HEIGHT;} else if (height > MAX_FRAME_HEIGHT) {height = MAX_FRAME_HEIGHT;}//计算x轴y轴坐标,可在此调整二维码框的位置int leftOffset = (screenResolution.x – width) / 2 ;int topOffset = ((screenResolution.y) /2 – height) / 2 ;framingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height);Log.d(TAG, "Calculated framing rect: " + framingRect);}return framingRect; }3、框中图片变形
CameraConfigurationManager.java中void setDesiredCameraParameters(Camera camera)方法
没有口水与汗水，就没有成功的泪水。
