.NET RDLC Reports GS1-128 Barcode Generator

The GS1-128 Barcode Generator for RDLC is a GS1 compatible barcode generation data carrier designed specifically for the linear GS1-128 symbology, which serves as the identifier for various types of GS1 data. This generator can be integrated into RDLC reports, enabling dynamic GS1-128 barcode images to be printed within client report definition (RDLC) files.

This guide provides a streamlined process for generating GS1-128 (EAN-128) barcodes within RDLC Local Reports using C#. The approach is optimized for ASP.NET (including ASP.NET Web Forms Framework and MVC) and Windows Forms (.NET Framework) projects integrated with the ReportViewer Control.

BarcodeLib provides step by step tutorials for printing barcodes in RDLC reports using C# in ASP.NET and Windows Forms applications.

• How to create barcodes in RDLC reports in ASP.NET
• How to create barcodes in RDLC reports in WinForms

The existing demonstration code for Code 128 can be adapted to generate GS1-128 barcodes as follows.

• Open the file Form1.cs in Visual Studio.
• Change the barcode type from BarcodeType.CODE128 to BarcodeType.EAN128.

GS1-128 barcodes in RDLC reports support the following character sets, aligned with GS1 General Specifications:

• Subset of ISO/IEC 646 International Reference Version (for GS1 Application Identifier (AI) element strings)
• Extended ASCII characters (ASCII 128 - 255)
• Four non data function characters (FNC1, FNC2, FNC3, FNC4). Only FNC1 is used in GS1-128 (FNC2 and FNC4 are excluded)
• Four code set selection characters (including single character code set shift)
• Three start characters and one stop character

Note: Manual addition of function characters, code set selection characters, or start/stop characters to the Data property is not required. The RDLC barcode generator library automatically inserts these characters into the GS1-128 symbol, which is critical for RDLC compliance with GS1 standards.

GS1-128 barcodes require a mandatory MOD 103 check digit (same as Code 128), which is essential for data integrity in RDLC reports:

• The check digit is not displayed in the human readable interpretation (HRI) of the barcode.
• The AddCheckSum property is not applicable to GS1-128. The barcode library automatically adds the check digit before the stop character for every GS1-128 symbol.

Note: Verify that the GS1-128 barcode in the RDLC report is scannable with a GS1 compliant scanner, confirming that AI data is decoded correctly. Missing auto inserted function characters (e.g., FNC1) will cause GS1-128 barcodes in RDLC to fail scanning. Do not manually edit the Data property to add these characters.

Customize GS1-128 dimensions for RDLC print layout compliance using the following core properties, aligned with GS1 standards:

• UOM: Unit of measure (PIXEL, CM, INCH). Select the same unit of measure as used in the RDLC Image report item.
• BarcodeWidth: GS1-128 barcode image width.
• BarcodeHeight: GS1-128 barcode image height.

• AutoResize: Must be set to false to enable the X and Y properties.
• X: Width of the narrow element (minimum value defined by GS1 application specifications).
• Y: Height of the bar module (optimized for RDLC report readability).
• LeftMargin / RightMargin / TopMargin / BottomMargin: Quiet zone (minimum width = 10X for GS1 and RDLC compliance).

Note: Verify in the RDLC report viewer that the GS1-128 barcode dimensions match the configured values and that no stretching occurs within the Image control. For high resolution RDLC printing (300 DPI), set the Resolution property to align with print layout settings to avoid blurry barcodes and ensure GS1 compliance.

The core workflow for generating GS1-128 barcodes in an RDLC Local Report is as follows:

• Initialize a Linear barcode object with the barcode type set to EAN128.
• Configure GS1-128 encoding data sourced from a database or a DataTable.
• Generate the GS1-128 barcode byte stream.
• Bind the byte stream to an RDLC Image report item.
• Render the report through the ReportViewer Control (ASP.NET / Windows Forms).

Key GS1-128 characteristics for RDLC include:

• Auto inserted function, start, and stop characters (no manual input required).
• Mandatory MOD 103 check digit (automatically generated by the library; AddCheckSum has no effect).

• • Important Barcode Dimension Size rules for RDLC and GS1 compliance:

• Quiet zones (minimum 10X for LeftMargin and RightMargin).
• Alignment of barcode dimensions with the RDLC Image control.
• Validation of GS1 data in PDF or Excel exports (ASP.NET) or printed reports (Windows Forms).

These settings must align with the properties of the RDLC Image report item to ensure accurate rendering.