Wie man Fehler behandelt und Barcode-Operationen in C# debuggt

Imports IronBarCode
Imports IronBarCode.Exceptions

' Success path: valid file present on disk
Dim filePath As String = "scanned-invoice.png"
' Failure path: file does not exist → caught by FileNotFoundException below
' Dim filePath As String = "warehouse-labels.pdf"

Try
    Dim results As BarcodeResults = BarcodeReader.Read(filePath)
    For Each result As BarcodeResult In results
        ' Print the detected symbology and decoded value for each barcode found
        Console.WriteLine($"[{result.BarcodeType}] {result.Value}")
    Next
Catch ex As IronBarCodePdfPasswordException
    ' PDF is encrypted — supply the password via PdfBarcodeReaderOptions before retrying
    Console.Error.WriteLine($"PDF requires password: {filePath} — {ex.Message}")
Catch ex As IronBarCodeFileException
    ' File is present but corrupted, locked, or in an unsupported format
    Console.Error.WriteLine($"Cannot read file: {filePath} — {ex.Message}")
Catch ex As FileNotFoundException
    ' Missing files throw FileNotFoundException, not IronBarCodeFileException
    Console.Error.WriteLine($"File not found: {filePath} — {ex.Message}")
Catch ex As IronBarCodeNativeException When ex.Message.Contains("DLL")
    ' The when filter routes only missing-DLL errors here; other native exceptions
    ' fall through to the IronBarCodeException block below
    Console.Error.WriteLine($"Missing native dependency: {ex.Message}")
Catch ex As IronBarCodeException
    ' Base catch for any IronBarcode-specific error not matched by the blocks above
    Console.Error.WriteLine($"IronBarcode error: {ex.GetType().Name} — {ex.Message}")
End Try

Imports IronBarCode
Imports IronBarCode.Exceptions

' Success path: valid file present on disk
Dim filePath As String = "scanned-invoice.png"
' Failure path: file does not exist → caught by FileNotFoundException below
' Dim filePath As String = "warehouse-labels.pdf"

Try
    Dim results As BarcodeResults = BarcodeReader.Read(filePath)
    For Each result As BarcodeResult In results
        ' Print the detected symbology and decoded value for each barcode found
        Console.WriteLine($"[{result.BarcodeType}] {result.Value}")
    Next
Catch ex As IronBarCodePdfPasswordException
    ' PDF is encrypted — supply the password via PdfBarcodeReaderOptions before retrying
    Console.Error.WriteLine($"PDF requires password: {filePath} — {ex.Message}")
Catch ex As IronBarCodeFileException
    ' File is present but corrupted, locked, or in an unsupported format
    Console.Error.WriteLine($"Cannot read file: {filePath} — {ex.Message}")
Catch ex As FileNotFoundException
    ' Missing files throw FileNotFoundException, not IronBarCodeFileException
    Console.Error.WriteLine($"File not found: {filePath} — {ex.Message}")
Catch ex As IronBarCodeNativeException When ex.Message.Contains("DLL")
    ' The when filter routes only missing-DLL errors here; other native exceptions
    ' fall through to the IronBarCodeException block below
    Console.Error.WriteLine($"Missing native dependency: {ex.Message}")
Catch ex As IronBarCodeException
    ' Base catch for any IronBarcode-specific error not matched by the blocks above
    Console.Error.WriteLine($"IronBarcode error: {ex.GetType().Name} — {ex.Message}")
End Try

Imports IronBarCode

Dim filePath As String = "scanned-invoice.png"

' Configure the reader to narrow the search to specific symbologies and use
' a thorough scan pass — narrows false positives and improves decode accuracy
Dim options As New BarcodeReaderOptions With {
    .ExpectBarcodeTypes = BarcodeEncoding.Code128 Or BarcodeEncoding.QRCode, ' limit scan to known formats
    .Speed = ReadingSpeed.Detailed,      ' slower but more thorough — use ExtremeDetail for damaged images
    .ExpectMultipleBarcodes = True       ' scan the full image rather than stopping at the first match
}

Dim results As BarcodeResults = BarcodeReader.Read(filePath, options)

' An empty result is not an exception — it means no barcode matched the configured options
If results Is Nothing OrElse results.Count = 0 Then
    ' Log the configured options alongside the warning so the cause is immediately actionable
    Console.Error.WriteLine($"[WARN] No barcodes found in: {filePath}")
    Console.Error.WriteLine($"  ExpectedTypes: {options.ExpectBarcodeTypes}")
    Console.Error.WriteLine($"  Speed: {options.Speed}")
    Console.Error.WriteLine($"  Action: Retry with ReadingSpeed.ExtremeDetail or broaden ExpectBarcodeTypes")
Else
    For Each result As BarcodeResult In results
        ' Points contains the four corner coordinates of the barcode in the image;
        ' use the first corner as a representative position indicator
        Dim pos As String = If(result.Points.Length > 0, $"{result.Points(0).X:F0},{result.Points(0).Y:F0}", "N/A")
        Console.WriteLine($"[{result.BarcodeType}] {result.Value} " &
                          $"(Page: {result.PageNumber}, Position: {pos})")
    Next
End If

Imports IronBarCode

Dim filePath As String = "scanned-invoice.png"

' Configure the reader to narrow the search to specific symbologies and use
' a thorough scan pass — narrows false positives and improves decode accuracy
Dim options As New BarcodeReaderOptions With {
    .ExpectBarcodeTypes = BarcodeEncoding.Code128 Or BarcodeEncoding.QRCode, ' limit scan to known formats
    .Speed = ReadingSpeed.Detailed,      ' slower but more thorough — use ExtremeDetail for damaged images
    .ExpectMultipleBarcodes = True       ' scan the full image rather than stopping at the first match
}

Dim results As BarcodeResults = BarcodeReader.Read(filePath, options)

' An empty result is not an exception — it means no barcode matched the configured options
If results Is Nothing OrElse results.Count = 0 Then
    ' Log the configured options alongside the warning so the cause is immediately actionable
    Console.Error.WriteLine($"[WARN] No barcodes found in: {filePath}")
    Console.Error.WriteLine($"  ExpectedTypes: {options.ExpectBarcodeTypes}")
    Console.Error.WriteLine($"  Speed: {options.Speed}")
    Console.Error.WriteLine($"  Action: Retry with ReadingSpeed.ExtremeDetail or broaden ExpectBarcodeTypes")
Else
    For Each result As BarcodeResult In results
        ' Points contains the four corner coordinates of the barcode in the image;
        ' use the first corner as a representative position indicator
        Dim pos As String = If(result.Points.Length > 0, $"{result.Points(0).X:F0},{result.Points(0).Y:F0}", "N/A")
        Console.WriteLine($"[{result.BarcodeType}] {result.Value} " &
                          $"(Page: {result.PageNumber}, Position: {pos})")
    Next
End If

Imports IronBarCode

' Enable IronBarcode's built-in logging — set BEFORE any read/write calls
' LoggingModes.All writes both debug output and file-level diagnostics
IronSoftware.Logger.LoggingMode = IronSoftware.Logger.LoggingModes.All
IronSoftware.Logger.LogFilePath = "ironbarcode-debug.log" ' path is relative to the working directory

' All subsequent operations will write internal processing steps to the log file:
' image pre-processing stages, format detection attempts, and native interop calls
Dim options As New BarcodeReaderOptions With {
    .Speed = ReadingSpeed.Detailed,
    .ExpectBarcodeTypes = BarcodeEncoding.All  ' scan for every supported symbology
}

Dim results As BarcodeResults = BarcodeReader.Read("problem-scan.tiff", options)
Console.WriteLine($"Read complete. Results: {results.Count}. See ironbarcode-debug.log for details.")

Imports IronBarCode

' Enable IronBarcode's built-in logging — set BEFORE any read/write calls
' LoggingModes.All writes both debug output and file-level diagnostics
IronSoftware.Logger.LoggingMode = IronSoftware.Logger.LoggingModes.All
IronSoftware.Logger.LogFilePath = "ironbarcode-debug.log" ' path is relative to the working directory

' All subsequent operations will write internal processing steps to the log file:
' image pre-processing stages, format detection attempts, and native interop calls
Dim options As New BarcodeReaderOptions With {
    .Speed = ReadingSpeed.Detailed,
    .ExpectBarcodeTypes = BarcodeEncoding.All  ' scan for every supported symbology
}

Dim results As BarcodeResults = BarcodeReader.Read("problem-scan.tiff", options)
Console.WriteLine($"Read complete. Results: {results.Count}. See ironbarcode-debug.log for details.")

Imports IronBarCode
Imports System.Diagnostics

' Lightweight wrapper that adds structured JSON observability to every read call.
' Call this in place of BarcodeReader.Read wherever elapsed-time and status logging is needed.
Function ReadWithDiagnostics(filePath As String, options As BarcodeReaderOptions) As BarcodeResults
    Dim sw As Stopwatch = Stopwatch.StartNew() ' start timing before the read so setup overhead is included
    Try
        Dim results As BarcodeResults = BarcodeReader.Read(filePath, options)
        sw.Stop()
        ' Emit a structured success entry to stdout — pipe to Fluentd, Datadog, or CloudWatch
        Console.WriteLine($"{{""file"":""{filePath}"",""status"":""ok"",""count"":{results.Count},""elapsed_ms"":{sw.ElapsedMilliseconds}}}")
        Return results
    Catch ex As Exception
        sw.Stop()
        ' Emit a structured error entry to stderr with exception type, message, and elapsed time
        Console.Error.WriteLine($"{{""file"":""{filePath}"",""status"":""error"",""exception"":""{ex.GetType().Name}"",""message"":""{ex.Message}"",""elapsed_ms"":{sw.ElapsedMilliseconds}}}")
        Throw ' rethrow so the caller's catch blocks still handle the exception normally
    End Try
End Function

Imports IronBarCode
Imports System.Diagnostics

' Lightweight wrapper that adds structured JSON observability to every read call.
' Call this in place of BarcodeReader.Read wherever elapsed-time and status logging is needed.
Function ReadWithDiagnostics(filePath As String, options As BarcodeReaderOptions) As BarcodeResults
    Dim sw As Stopwatch = Stopwatch.StartNew() ' start timing before the read so setup overhead is included
    Try
        Dim results As BarcodeResults = BarcodeReader.Read(filePath, options)
        sw.Stop()
        ' Emit a structured success entry to stdout — pipe to Fluentd, Datadog, or CloudWatch
        Console.WriteLine($"{{""file"":""{filePath}"",""status"":""ok"",""count"":{results.Count},""elapsed_ms"":{sw.ElapsedMilliseconds}}}")
        Return results
    Catch ex As Exception
        sw.Stop()
        ' Emit a structured error entry to stderr with exception type, message, and elapsed time
        Console.Error.WriteLine($"{{""file"":""{filePath}"",""status"":""error"",""exception"":""{ex.GetType().Name}"",""message"":""{ex.Message}"",""elapsed_ms"":{sw.ElapsedMilliseconds}}}")
        Throw ' rethrow so the caller's catch blocks still handle the exception normally
    End Try
End Function

Imports IronBarCode
Imports IronBarCode.Exceptions
Imports System.Diagnostics

' Enable built-in logging for the entire batch run so internal processing steps
' are captured in the log file alongside the per-file console output
IronSoftware.Logger.LoggingMode = IronSoftware.Logger.LoggingModes.All
IronSoftware.Logger.LogFilePath = "batch-run.log"

' Collect all files in the directory — SearchOption.TopDirectoryOnly skips subdirectories
Dim files As String() = Directory.GetFiles("scans/", "*.*", SearchOption.TopDirectoryOnly)

Dim options As New BarcodeReaderOptions With {
    .Speed = ReadingSpeed.Balanced,                                    ' balances throughput vs accuracy
    .ExpectBarcodeTypes = BarcodeEncoding.Code128 Or BarcodeEncoding.QRCode, ' limit to known formats
    .ExpectMultipleBarcodes = True                                     ' scan each file fully
}

' Three outcome counters: success (decoded), empty (read OK but no barcode found), fail (exception)
Dim successCount As Integer = 0
Dim failCount As Integer = 0
Dim emptyCount As Integer = 0
Dim errors As New List(Of (File As String, Error As String))() ' per-file error context for root cause analysis
Dim sw As Stopwatch = Stopwatch.StartNew()

For Each file As String In files
    Try
        Dim results As BarcodeResults = BarcodeReader.Read(file, options)

        ' Empty result is not an exception — the file was read but contained no matching barcode
        If results Is Nothing OrElse results.Count = 0 Then
            emptyCount += 1
            errors.Add((file, "No barcodes detected")) ' record so caller can adjust options
            Continue For
        End If

        For Each result As BarcodeResult In results
            Console.WriteLine($"{Path.GetFileName(file)} | {result.BarcodeType} | {result.Value}")
        Next
        successCount += 1
    Catch ex As IronBarCodePdfPasswordException
        ' PDF is password-protected — supply password via PdfBarcodeReaderOptions to recover
        failCount += 1
        errors.Add((file, "Password-protected PDF"))
    Catch ex As IronBarCodeFileException
        ' File is corrupted, locked, or in an unsupported image format
        failCount += 1
        errors.Add((file, $"File error: {ex.Message}"))
    Catch ex As FileNotFoundException
        ' File was in the directory listing but deleted before the read completed (race condition)
        failCount += 1
        errors.Add((file, $"File not found: {ex.Message}"))
    Catch ex As IronBarCodeException
        ' Catch-all for any other IronBarcode-specific errors not handled above
        failCount += 1
        errors.Add((file, $"{ex.GetType().Name}: {ex.Message}"))
    Catch ex As Exception
        ' Unexpected non-IronBarcode error — log the full type for investigation
        failCount += 1
        errors.Add((file, $"Unexpected: {ex.GetType().Name}: {ex.Message}"))
    End Try
Next

sw.Stop()

' Summary report — parse failCount > 0 in CI/CD to set a non-zero exit code
Console.WriteLine(vbCrLf & "--- Batch Summary ---")
Console.WriteLine($"Total files:    {files.Length}")
Console.WriteLine($"Success:        {successCount}")
Console.WriteLine($"Empty reads:    {emptyCount}")
Console.WriteLine($"Failures:       {failCount}")
Console.WriteLine($"Elapsed:        {sw.Elapsed.TotalSeconds:F1}s")

If errors.Any() Then
    Console.WriteLine(vbCrLf & "--- Error Details ---")
    For Each errorDetail In errors
        Console.Error.WriteLine($"  {Path.GetFileName(errorDetail.File)}: {errorDetail.Error}")
    Next
End If

Imports IronBarCode
Imports IronBarCode.Exceptions
Imports System.Diagnostics

' Enable built-in logging for the entire batch run so internal processing steps
' are captured in the log file alongside the per-file console output
IronSoftware.Logger.LoggingMode = IronSoftware.Logger.LoggingModes.All
IronSoftware.Logger.LogFilePath = "batch-run.log"

' Collect all files in the directory — SearchOption.TopDirectoryOnly skips subdirectories
Dim files As String() = Directory.GetFiles("scans/", "*.*", SearchOption.TopDirectoryOnly)

Dim options As New BarcodeReaderOptions With {
    .Speed = ReadingSpeed.Balanced,                                    ' balances throughput vs accuracy
    .ExpectBarcodeTypes = BarcodeEncoding.Code128 Or BarcodeEncoding.QRCode, ' limit to known formats
    .ExpectMultipleBarcodes = True                                     ' scan each file fully
}

' Three outcome counters: success (decoded), empty (read OK but no barcode found), fail (exception)
Dim successCount As Integer = 0
Dim failCount As Integer = 0
Dim emptyCount As Integer = 0
Dim errors As New List(Of (File As String, Error As String))() ' per-file error context for root cause analysis
Dim sw As Stopwatch = Stopwatch.StartNew()

For Each file As String In files
    Try
        Dim results As BarcodeResults = BarcodeReader.Read(file, options)

        ' Empty result is not an exception — the file was read but contained no matching barcode
        If results Is Nothing OrElse results.Count = 0 Then
            emptyCount += 1
            errors.Add((file, "No barcodes detected")) ' record so caller can adjust options
            Continue For
        End If

        For Each result As BarcodeResult In results
            Console.WriteLine($"{Path.GetFileName(file)} | {result.BarcodeType} | {result.Value}")
        Next
        successCount += 1
    Catch ex As IronBarCodePdfPasswordException
        ' PDF is password-protected — supply password via PdfBarcodeReaderOptions to recover
        failCount += 1
        errors.Add((file, "Password-protected PDF"))
    Catch ex As IronBarCodeFileException
        ' File is corrupted, locked, or in an unsupported image format
        failCount += 1
        errors.Add((file, $"File error: {ex.Message}"))
    Catch ex As FileNotFoundException
        ' File was in the directory listing but deleted before the read completed (race condition)
        failCount += 1
        errors.Add((file, $"File not found: {ex.Message}"))
    Catch ex As IronBarCodeException
        ' Catch-all for any other IronBarcode-specific errors not handled above
        failCount += 1
        errors.Add((file, $"{ex.GetType().Name}: {ex.Message}"))
    Catch ex As Exception
        ' Unexpected non-IronBarcode error — log the full type for investigation
        failCount += 1
        errors.Add((file, $"Unexpected: {ex.GetType().Name}: {ex.Message}"))
    End Try
Next

sw.Stop()

' Summary report — parse failCount > 0 in CI/CD to set a non-zero exit code
Console.WriteLine(vbCrLf & "--- Batch Summary ---")
Console.WriteLine($"Total files:    {files.Length}")
Console.WriteLine($"Success:        {successCount}")
Console.WriteLine($"Empty reads:    {emptyCount}")
Console.WriteLine($"Failures:       {failCount}")
Console.WriteLine($"Elapsed:        {sw.Elapsed.TotalSeconds:F1}s")

If errors.Any() Then
    Console.WriteLine(vbCrLf & "--- Error Details ---")
    For Each errorDetail In errors
        Console.Error.WriteLine($"  {Path.GetFileName(errorDetail.File)}: {errorDetail.Error}")
    Next
End If