使用BarcodeLib生成条码图片报错：图片尺寸不足求助

Root Cause #

The error happens because the total width needed to render your CODE128 barcode (based on the length of productid and CODE128's module structure) is bigger than the fixed image width you set. When the library tries to shrink bars to fit, their width drops below 1 pixel, which isn't allowed.

Fixes to Try #

1. Use Bar Width/Height Instead of Fixed Image Dimensions #

Instead of hardcoding the total image width, define the width of individual bars and let the library calculate the correct total image width. This guarantees bars never go below 1 pixel:

BarcodeLib.Barcode b = new BarcodeLib.Barcode();
string productid = item.ProductId.Trim(); // Remove extra whitespace
// Encode with 1px bar width, 120px bar height, default black/white colors
var img1 = b.Encode(BarcodeLib.TYPE.CODE128, productid, Color.Black, Color.White, 1, 120);

If you want thicker bars, increase the 1 value to 2 or higher.

2. Calculate the Minimum Required Image Width #

If you must use a fixed image width, compute the minimum width needed for your productid:

• CODE128 uses 11 modules per character, plus 3 extra characters (start, checksum, stop) → total modules = (productid.Length + 3) * 11
• Add 20px for default left/right margins
• Minimum image width = totalModules + 20

For example, if productid is 20 characters long:
(20 +3)*11 +20 = 253 +20 =273px → 290px should work. But if your productid is longer (e.g., 30 chars: (30+3)*11+20= 363+20=383px), you need to set the width to at least that value.

3. Clean Up Your Product ID #

Make sure productid has no hidden whitespace or non-printable characters that could add unexpected length:

string productid = item.ProductId.Trim();
// Optional: Remove non-alphanumeric characters if allowed by your use case
productid = Regex.Replace(productid, @"[^a-zA-Z0-9]", "");

4. Update the BarcodeLib NuGet Package #

Your current version (5.0.2) might have sizing bugs. Check for newer versions of the BarcodeLib package in NuGet and update to the latest stable release.

内容的提问来源于stack exchange，提问作者Mohamed Amine Benessy