[SerializableAttribute()]
public enum BarcodeReaderErrorMode
Value | Member | Description |
---|---|---|
0 | Default |
Default mode. No errors are ignored and an exception will be thrown immediately if an error occurs at any time. |
1 | IgnoreAll |
Ignore all errors. When an error occurs, the exception will be saved and passed to the next BarcodeReader.ReadSymbology event (in the BarcodeReadSymbologyEventArgs.Error member). |
This BarcodeReaderErrorMode enumeration is used as the type for the BarcodeReader.ErrorMode property and is used to determine how to handle the errors when reading barcodes.
The BarcodeReader object might encounter errors when reading barcodes. By default, when an error is encountered, an exception is thrown, usually of type BarcodeException with the BarcodeException.Code set to one of the BarcodeExceptionCode enumeration members, providing more details regarding the error. This is the default behavior.
Sometimes, this behavior may no be desired, for example:
The application is trying to decode barcodes on an "if found and correct" bases. If there were corrupted barcodes, the action is to ignore this and continue. In this case, you can set the error mode to IgnoreAll.
The application is reading multiple barcodes from an image, and the action is to ignore the corrupted barcodes and return only the valid ones found. In this case, you can set the error mode to IgnoreAll and subscribe to the BarcodeReader.ReadSymbology event to get a notification when an error occurs and save the exception for later use. You can then handle these errors when all barcodes are read and the read method returns.
The LEADTOOLS C# Barcode Demo will change the value of ErrorMode to IgnoreAll and use the BarcodeReader.ReadSymbology event to show the errors encountered in a list box.
Note that when the BarcodeReader does not find any barcodes in the image, no exception is thrown. Instead, BarcodeReader.ReadBarcode and BarcodeReader.ReadBarcodes methods will return null (Nothing in VB) or an empty array of BarcodeData instead.
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Barcode;
using Leadtools.ImageProcessing;
private List<Exception> myErrors; // List of errors
public void BarcodeReader_ErrorModeExample()
{
string imageFileName = Path.Combine(LEAD_VARS.ImagesDir, "Barcode1.tif");
// Create a Barcode engine
BarcodeEngine engine = new BarcodeEngine();
// Get the Barcode reader instance
BarcodeReader reader = engine.Reader;
// Load the image
using (RasterCodecs codecs = new RasterCodecs())
{
using (RasterImage image = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1))
{
myErrors = new List<Exception>();
// Disable the errors
reader.ErrorMode = BarcodeReaderErrorMode.IgnoreAll;
// Subscribe to the ReadSymbology event
reader.ReadSymbology += new EventHandler<BarcodeReadSymbologyEventArgs>(myReader_ReadSymbology);
// Read all barcodes in the image
reader.ReadBarcodes(image, LeadRect.Empty, 0, null);
reader.ReadSymbology -= new EventHandler<BarcodeReadSymbologyEventArgs>(myReader_ReadSymbology);
// Show the errors
if (myErrors.Count > 0)
{
Console.WriteLine("Errors encountered:");
foreach (Exception error in myErrors)
{
Console.WriteLine(error.Message);
}
}
}
}
}
private void myReader_ReadSymbology(object sender, BarcodeReadSymbologyEventArgs e)
{
// If we encounter an error, save it to our list
if (e.Error != null)
{
myErrors.Add(e.Error);
}
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images";
}