主要有三點：

1、介面繪製，包括4個邊角、上下滾動的橫線、在畫布上新增文字

2、調整二維碼掃描框的位置。

3、解決圖片被壓變形的問題。

1、介面繪製

ViewfinderView.java中onDraw()方法

@Override public void onDraw(Canvas canvas) { // 中間的掃描框，你要修改掃描框的大小，去CameraManager裡面修改 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 ); // 初始化中間線滑動的最上邊和最下邊 if (!isFirst) { isFirst = true; slideTop = frame.top; slideBottom = frame.bottom; } // 獲取螢幕的寬和高 int width = canvas.getWidth(); int height = canvas.getHeight(); // 畫出掃描框外面的陰影部分，共四個部分，掃描框的上面到螢幕上面，掃描框的下面到螢幕下面 // 掃描框的左邊面到螢幕左邊，掃描框的右邊到螢幕右邊 // 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 { // 畫掃描框邊上的角，總共8個部分 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); //繪製中間的線,每次重新整理介面，中間的線往下移動SPEEN_DISTANCE slideTop += 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); //畫掃描框下面的字 //            paint.setColor(Color.WHITE);    //            paint.setTextSize(TEXT_SIZE * density);    //            paint.setAlpha(0x40);    //            paint.setTypeface(Typeface.create(System, Typeface.BOLD));   //            String text = 將二維碼放入框內, 即可自動掃描;  //            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); } } //只重新整理掃描框的內容，其他地方不重新整理 postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top, frame.right, frame.bottom); } }</resultpoint></resultpoint></resultpoint>

2、調整位置

如果不設定全屏，掃描框的位置和取圖的位置高度目測會有50px誤差， 不全屏公式：((Y - 標題欄 - 狀態列)/2 - 掃描框高度)/2 = y軸座標 只要不全屏：就會有誤差，導致框中的二維碼靠上或者遠離二維碼才會掃描成功 如果設定為全屏，就不會有誤差，請了解內情的大神告知筆者，想知道什麼原因造成 CameraManager.java 中 getFramingRect()方法 public Rect getFramingRect() { Point screenResolution = configManager.getScreenResolution(); if (framingRect == null) { if (camera == null) { return null; } /* 確定在固定比例解析度下二維碼掃描框的寬高*/  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; } //計算x軸y軸座標,可在此調整二維碼框的位置 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、框中圖片變形

CameraConfigurationManager.java中void setDesiredCameraParameters(Camera camera)方法 /** * Sets the camera up to take preview images which are used for both preview * and decoding. We detect the preview format here so that * buildLuminanceSource() can build an appropriate LuminanceSource subclass. * In the future we may want to force YUV420SP as it's the smallest, and the * planar Y can be used for barcode scanning without a copy in some cases. */ void setDesiredCameraParameters(Camera camera) { // Camera.Parameters parameters = camera.getParameters(); // Log.d(TAG, Setting preview size:  + cameraResolution); // parameters.setPreviewSize(cameraResolution.x, cameraResolution.y); // setFlash(parameters); // setZoom(parameters); // //setSharpness(parameters); // //modify here // camera.setDisplayOrientation(90); // camera.setParameters(parameters); Camera.Parameters parameters = camera.getParameters(); List<size> supportedPreviewSizes = parameters .getSupportedPreviewSizes(); int position = 0; if (supportedPreviewSizes.size() > 2) { position = supportedPreviewSizes.size() / 2 + 1;// supportedPreviewSizes.get(); } else { position = supportedPreviewSizes.size() / 2; } int width = supportedPreviewSizes.get(position).width; int height = supportedPreviewSizes.get(position).height; Log.d(TAG, Setting preview size:  + cameraResolution); camera.setDisplayOrientation(90); cameraResolution.x = width; cameraResolution.y = height; parameters.setPreviewSize(width, height); setFlash(parameters); setZoom(parameters); // setSharpness(parameters); camera.setParameters(parameters); }</size>