Reading bar codes

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Reading bar codes

Overview

Reading a bar code in a WINDEV application

Reading a bar code in a WEBDEV site

Reading a bar code in an Android application

Reading a bar code in an iPhone/iPad application

Related examples

See also

Reading bar codes

Overview

WINDEV, WEBDEV and WINDEV Mobile allow you to create applications for reading bar codes.

In WINDEV, the bar codes are read via a specific device plugged into the serial port of the computer.
For the QR Code bar codes, you also have the ability to read a bar code found in an image.
For more details, see Reading a bar code in a WINDEV application.
In WEBDEV, it is possible to read a bar code in an image.
For more details, see Reading a bar code in a WEBDEV site.
In the Android applications, the bar code is read via the camera of the device.
For more details, see Reading a bar code in an Android application.
In iPhone/iPad applications, it is possible to read a wide variety of bar codes. You can:
- read the bar code via the device camera.
- read a bar code found in an image.
For more details, see Reading a bar code in an iOS application.

Reading a bar code in a WINDEV application

Reading bar codes with a WINDEV application: Using a specialized device

To read a bar code via a specialized device:

Connect a specific device to the serial port of your computer (depending on the device used, check whether the keyboard is not set to uppercase characters and/or whether the device is configured for an english keyboard).
Read the value of the bar code with the following functions for managing serial ports:
- sOpen, which opens and initializes the specified serial port (or parallel port).
- sRead, which reads a string in the input buffer of the specified serial port.

The value of the bar code can be displayed in an edit control.

Remark: A Bar Code control can also be used in the window editor.

Example used to read a bar code with a specific device connected to the serial port COM1:

// Declare the variables
// Define the number of characters that must be read
nNbCharToRead is int = 13
// Number of pending bytes in the buffer
nNbPendingByte is int
sBuffer is string // Content of the buffer
nSerialPort is int = 1 // COM1 serial port

// Open and initialize the serial port COM1
IF sOpen(nSerialPort, 5000, 5000) THEN
// Read the bar code
// Retrieve the number of pending bytes
nNbPendingByte = sInEntryQueue(nSerialPort)
// Retrieve the value of the bar code only
// if at least 13 characters have been read
IF nNbPendingByte >= nNbCharToRead THEN
sBuffer = sRead(nSerialPort, nNbPendingByte)
// Retrieve the first 13 characters read
sBuffer = Left(sBuffer, 13)
// Display the value of the bar code
// in the "EDT_BarCode" edit control
EDT_BarCode = sBuffer
END
END

Reading a QR Code bar code found in an image (physical image or memory image)

To read a QR Code bar code found in an image:

Select the image that contains the bar code to decode. This image can be:
- an image in an Image control.
- an image file.
- an image in memory.
Declare a BarCode variable if necessary. The characteristics of the QR Code bar code will be saved in this variable.
Use BCDecode to decode the QR Code.

Example: Reading a bar code read by a Web Camera and stored in memory:

// Decode a QR Code from a Camera control
s is Buffer
s = dSaveImageBMP(CAM_MyCamera, inMemory)
bc is BarCode
bc = BCDecode(s)
IF ErrorOccurred = False _AND_ bc.TypeBarCode = BC_QRCODE ...
_AND_ bc.TypeContent = bcTypeEmail THEN
Info("Email address: " + bc.Content)
END

Reading a bar code in a WEBDEV site

Reading a bar code in an image

In WEBDEV sites, it is also possible to read the characteristics of a bar code in an image.

To read a bar code found in an image:

Select the image that contains the bar code to decode. This image can be:
- an image in an Image control.
- an image file.
- an image in memory.
Declare a BarCode variable if necessary. The characteristics of the bar code will be saved in this variable.
Use BCDecode to decode the bar code.

Example: Reading a bar code in an Image control:

// Decode a QR Code found in an Image control
bc is BarCode
bc = BCDecode(IMG_BarCode)
IF ErrorOccurred = False _AND_ bc.TypeBarCode = BC_QRCODE ...
_AND_ bc.TypeContent = bcTypeEmail THEN
Info("Email address: " + bc.Content)
END

Reading a bar code in an Android application

Direct bar code reading with an Android application

Two modes are available for reading bar codes:

Reading bar codes with BCCapture. This function decodes the information stored in a bar code by using the camera of the device.
Remarks:
- This function opens a new window that displays the preview from the device camera. Then, you must:
  - center the bar code to decode in the relevant area.
  - validate like for a standard snapshot.
- In Android, the Zxing library is used for decoding bar codes (http://code.google.com/p/zxing). If this library is not found on the device, it will be automatically proposed for download.
Reading bar codes via the Camera control.
Simply enable bar code reading in the Camera control. A specific process is run whenever the bar code is read. This process is used to get the characteristics of the bar code read in a variable of type BarCode. For more details, see Camera control: decoding the bar codes.

Reading a bar code in an iPhone/iPad application

Direct reading of QR Code bar codes (BCCapture function)

Bar codes are read directly by BCCapture. This function decodes the information stored in a bar code by using the camera of the device.

Remark: This function opens a new window that displays the preview from the device camera. Then, you must:

center the bar code to decode in the relevant area.
validate like for a standard snapshot.

The characteristics of the bar code are then stored in a variable of type BarCode. The value of the bar code is returned by the RoughValue property and can be displayed in a Bar Code control.

For example:

// Capture the bar code
MyBC is BarCode
MyBC = BCCapture()

// Retrieve the content of the bar code and display it
sResult is string = MyBC.RoughValue
BAC_MyBarCodeControl = sResult

Direct bar code reading (Camera control)

Bar codes are read directly using the Camera control in decoding mode.

Remark: The user frames the bar code. A specific process is run whenever the bar code is read. This process is used to get the characteristics of the bar code read in a variable of type BarCode. The value of the bar code is returned by the RoughValue property and can be displayed in a Bar Code control.

For example:

// Decoding a Bar Code process
PROCÉDURE DecodeBarCode(bc is BarCode)
// Retrieve the content of the bar code and display it
sResult is string = bc.RoughValue
BAC_MyBarCodeControl = sResult

For more details, see Camera control: decoding the bar codes.

Reading a bar code in an image

In iPhone/iPad applications, it is also possible to read the characteristics of a bar code in an image.

To read a bar code found in an image:

Select the image that contains the bar code to decode. This image can be:
- an image in an Image control.
- an image file.
- an image in memory.
Declare a BarCode variable if necessary. The characteristics of the bar code will be saved in this variable.
Use BCDecode to decode the bar code.

Example of a barcode read by a Web Camera and stored in memory:

Related Examples:

Unit examples (WINDEV): The Bar Code control

[ + ] Using a Bar Code control