我用的是网上一个现成的例子，可以直接用，但是高宽不合适，现在主流都是大屏幕手机了，所以需要更改。
找到CameraManager 类，更改下面的方法
public Rect getFramingRect() { Point screenResolution = configManager.getScreenResolution(); if (framingRect == null) { if (camera == null) { return null; } int width = screenResolution.x * 3 / 5; // if (width < MIN_FRAME_WIDTH) { // width = MIN_FRAME_WIDTH; // } else if (width > MAX_FRAME_WIDTH) { // width = MAX_FRAME_WIDTH; // } int height = screenResolution.y * 3 / 5; // if (height < MIN_FRAME_HEIGHT) { // height = MIN_FRAME_HEIGHT; // } else if (height > MAX_FRAME_HEIGHT) { // height = MAX_FRAME_HEIGHT; // } /* 自定义，以宽高其中一个窄的为正方形的边长 */ width = (width>height?height:width); height = (width<height?width:height); int leftOffset = (screenResolution.x - width) / 2; // int topOffset = (screenResolution.y - height) / 2; int topOffset = (screenResolution.y - height) / 2 - 40; /* 自定义，放上一点 */ framingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height); Log.d(TAG, "Calculated framing rect: " + framingRect); } return framingRect; }