ReadSymbology Event (original) (raw)
Summary
Occurs for every barcode symbology read.
Syntax
C#
Objective-C
C++/CLI
Java
Python
@property (nonatomic, weak, nullable) id<LTReadSymbologyDelegate> delegate public void addReadSymbologyListener(BarcodeReadSymbologyListener listener)
public void removeReadSymbologyListener(BarcodeReadSymbologyListener listener)
public:
event EventHandler<BarcodeReadSymbologyEventArgs^>^ ReadSymbology
def ReadSymbology(sender,e): # sender: BarcodeReader e: BarcodeReadSymbologyEventArgs Event Data
The event handler receives an argument of type BarcodeReadSymbologyEventArgs containing data related to this event. The following BarcodeReadSymbologyEventArgs properties provide information specific to this event.
| Property | Description |
|---|---|
| Data | Gets the barcode data found. |
Example
This example shows how to use ReadSymbology to get the current status of barcode reading.
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Barcode;
using Leadtools.ImageProcessing;
public void BarcodeReader_ReadSymbologyExample()
{
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))
{
// Subscribe to the ReadSymbology event
reader.ReadSymbology += new EventHandler<BarcodeReadSymbologyEventArgs>(reader_ReadSymbology);
// Read all barcodes in the image
reader.ReadBarcodes(image, LeadRect.Empty, 0, null);
reader.ReadSymbology -= new EventHandler<BarcodeReadSymbologyEventArgs>(reader_ReadSymbology);
}
}
}
private void reader_ReadSymbology(object sender, BarcodeReadSymbologyEventArgs e)
{
if (e.Operation == BarcodeReadSymbologyOperation.PreRead)
{
// Before reading, show the symbologies the engine is going to try to read
Console.WriteLine("Trying to read the following symbologies:");
BarcodeSymbology[] symbologies = e.GetSymbologies();
for (int i = 0; i < symbologies.Length; i++)
{
Console.Write(symbologies[i]);
if (i != (symbologies.Length - 1))
{
Console.Write(", ");
Console.WriteLine(e.Options.FriendlyName);
}
else
{
Console.WriteLine();
}
}
}
else if (e.Operation == BarcodeReadSymbologyOperation.PostRead)
{
if (e.Error == null)
{
// No errors
BarcodeData barcode = e.Data;
if (barcode != null)
{
// Found a barcode, show it
Console.WriteLine(" {0} at {1} with data {2}", barcode.Symbology, barcode.Bounds, barcode.Value);
}
else
{
Console.WriteLine(" No barcodes found");
}
}
else
{
// Show the error
Console.WriteLine("Error: {0}", e.Error.Message);
// Tell the reader top stop reading barcodes
e.Status = BarcodeReadSymbologyStatus.Abort;
}
}
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images";
}