BCCapture (Function)

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Use conditions
Handling errors
Application in the background: Specific case from Android 10

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BCCapture (Function)

In french: CBCapture

Decodes the information stored in a bar code by using the device camera (Android, iPhone, iPad).

Tip: Use the Camera control whenever possible:

The Camera control can also be used to decode bar codes directly. For more details, see Camera control: decoding bar codes.
It is recommended to replace this function with an application window containing a Camera control that allows decoding bar codes. For more details, see Camera control: decoding bar codes.

Example

// Decode a QR Code
bc is BarCode
bc = BCCapture()
IF ErrorOccurred = False _AND_ bc.TypeContent = bcTypeEmail THEN
    	Info("Email address: " + bc.RoughValue)
END

Syntax

<Result> = BCCapture([<Bar code type> [, <Enable flash>]])

<Result>: BarCode variable

BarCode variable initialized with the information read in the bar code.
Remark: The TypeBarCode property of the BarCode variable is not updated: it always corresponds to "QRCode".

<Bar code type>: Optional Integer constant

Type of bar code that can be decoded:
BC_AZTEC Aztec bar code.
This type of bar code is available from iOS 7.
BC_CODE128 Code128 bar code.
This type of bar code is available from iOS 7.
BC_CODE39 Code39 bar code.
This type of bar code is available from iOS 7.
BC_CODE93 Code93 bar code.
This type of bar code is available from iOS 7.
BC_DATAMATRIX DATAMATRIX bar code.
Not available.
BC_EAN128 EAN128 bar code.
This type of bar code is available from iOS 7.
BC_EAN13 EAN13 bar code.
This type of bar code is available from iOS 7.
BC_EAN8 EAN8 bar code.
This type of bar code is available from iOS 7.
BC_INTER2OF5 Interleaved 2 of 5 bar code.
This type of bar code is available from iOS 7.
BC_PDF417 PDF417 bar code.
This type of bar code is available from iOS 7.
BC_QRCODE QR Code bar code.
BC_UPCA UPC-A bar code.
Not available.
BC_UPCE UPC-E bar code.
This type of bar code is available from iOS 7.
BC_ALL All the types of bar codes supported by this function can be decoded.

If this parameter is not specified, all types of codes supported by this function can be decoded.
Starting with IOS 7, the following bar codes can be decoded: QR Code, UPCE, Code39, Code39Mod43, EAN13, EAN8, Code93, Code128, PDF417 and Aztec.

<Enable flash>: Optional boolean

Flash management mode:
True to enable the flash,
False (default) to disable the flash.

Remarks

Use conditions

In an Android application:

BCCapture opens a new window that displays the camera preview stream. Then, you must:
- center the bar code to decode in the relevant area.
- tap to read the bar code.
The Zxing library is used to decode bar codes (http://code.google.com/p/zxing). If this library is not on the device, it will be automatically available for download.
Caution: This library requires the landscape mode of the device.

For iPhone/iPad applications:

BCCapture opens a new window that displays the camera preview stream. Then, you just need to center the bar code to decode in the relevant area.
The window used to take photos is included in the WINDEV Mobile application. No additional library is required.

Handling errors

To determine whether the bar code failed to be read, use the ErrorOccurred variable.

The function will fail in the following cases:

if it is used in the simulator,
if it is used in the emulator,
if it is used in a device not equipped with a camera.
if the "Cancel" button was used. In this case, the TypeBarCode property of the BarCode variable will be different from BC_QRCODE.

If the barcode is decoded but its type is not recognized, the TypeBarCode property of the BarCode variable will correspond to the BC_UNKNOWN constant.

Application in the background: Specific case from Android 10

From Android 10, it is no longer possible to open a window when the application is in the background.

BCCapture can open a window. If this function is used while the application is in the background, a fatal error will occur.

Tips:

It is possible to determine if the application is in the background using InBackgroundMode.
If an application needs to interact with the user while it is in the background, the solution is to display a notification (via the Notification type). The application will be brought back to the foreground when the notification is clicked, if the ActivateApplication property is set to True. You can also open a window from the procedure passed to the ActionClick property.

For more details, see Android 10: Behavior of applications in the background.

Related Examples:

Cross-platform examples (WINDEV Mobile): WM Stocks

[ + ] This application is used to perform stocktaking and to save the results in a database.
The example is used to create entries/exits in the stock, by directly scanning the bar code of products.
It is optimized to be run on tablets.

Android (WINDEV Mobile): Android Inventory

[ + ] This application is used to perform inventories and to save the results in a database.

Business / UI classification: Neutral code

Component: wd300android.aar