Decode the data within the viewfinder rectangle, and time how long it took. For efficiency, reuse the same reader objects from one decode to the next.

A single preview frame will be returned to the handler supplied. The data will arrive as byte[] in the message.obj field, with width and height encode

设置扫码框的大小 @param width The width in pixels to scan. @param height The height in pixels to scan.

@param newSetting if {@code true}, light should be turned on if currently off. And vice versa.

A factory method to build the appropriate LuminanceSource object based on the format of the preview buffers, as described by Camera.Parameters. @para

Closes the camera driver if still in use.

绘制矩形框的四个角 @param canvas @param rect

绘制聚焦框

绘制激光线

Calculates the framing rect which the UI should draw to show the user where to place the barcode. This target helps with alignment as well as forces t

get apposite barcode type @param type @return

一些初始化操作

Reads, one time, values from the camera that are needed by the app.

Opens the requested camera with {@link Camera#open(int)}, if one exists. @param cameraId camera ID of the camera to use. A negative value or {@link

Opens the camera driver and initializes the hardware parameters. @param holder The surface object which the camera will draw preview frames into. @th

Asks the camera hardware to begin drawing preview frames to the screen.

Tells the camera to stop drawing preview frames.