Set UTF-8 encoding for QR code generation to support Unicode characters

[Copilot]

ZXing.Net defaults to ISO-8859-1 encoding when no CHARACTER_SET hint is specified. Unicode characters outside the Latin-1 range (U+0000-U+00FF) get replaced with ? (0x3F), causing emojis like 😎 (U+1F60E) to encode as 3F 3F instead of proper UTF-8 bytes F0 9F 98 8E.

Changes

• Set CHARACTER_SET hint to "UTF-8" for QR_CODE format before encoding in EncodePage.xaml.cs

// Set UTF-8 encoding to properly handle Unicode characters (e.g., emojis)
if (writer.Format == BarcodeFormat.QR_CODE)
{
    writer.Options.Hints[EncodeHintType.CHARACTER_SET] = "UTF-8";
}

Other barcode formats remain unaffected.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>QR code generator doesn't properly hande Unicode characters</issue_title>
<issue_description>Hi,

I noticed when trying to create a QR code that contains Unicode 6 character 😎 the QR generated outputs data

3F 3F and later on tested that any Unicode emoji results in 3F 3F

and a QR generator on my browser outputs

F0 9F 98 8E which is the correct hex data for U+1F60E

Both are on error correction H

barcodrod.io QR

browser extension QR

edit: tested that the program can decode QR correctly from image file and display the Unicode character on the lower QR code

--
Version: 1.8.1.0 (Windows store)</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes QR code generator doesn't properly hande Unicode characters #31

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