由 DelphiZXingQRCode 编码的 QR 码无法通过 ErrorCorrectionLevel > Low 解码

Question

我正在使用这个 Delphi-Unit。我被迫使用这个旧的 Delphi 实现，所以不要问这个： https://github.com/foxitsoftware/DelphiZXingQRCode

只要我将纠错级别保持在"Low"，它生成的二维码就可以被任何解码器解码。如果我提高纠错级别，生成的代码将无法被我目前尝试过的任何解码器解码。但是我（按标准）被迫使用中等纠错级别，不多也不少。

但是不清楚如何提高纠错级别（从现在开始是ecl）。我假设它被硬编码在文件 DelphiZXingQRCode 的第 3491 行：Level.FBits := 1。我找到了一些关于代表 ecls 的 hexnumbers 的信息，但我现在找不到了。但我尝试将这些十六进制数字作为位，QRcode 上的 ecl 位相应地发生了变化。所以我假设十六进制数是正确的（1=低，0=中，2=高，3=四分位数）。

这是一个带有 Level.FBits := 2 的 QRcode 示例，这意味着我希望 ecl 为 "High"。内容是"Hello world"。中间的十字图像是我必须实施的标准 [原文如此] 的一部分，所以不要问这个。

有人知道如何解决这个问题吗？我试过……好吧……我试着理解代码，但它太多了。我无法修复它。如果我无法让其他人修复它，我将不得不……寻找其他解决方案。这将是一个问题。

Answer 1

已解决。请参阅下面的代码。方法 GenerateQRCode() 现在需要 ErrorCorrectionLevel 的参数：整数 0-3。似乎工作。我不得不删除一些未更改的行，因为该文件对于 Whosebug 来说太大了。合并自己。

    unit DelphiZXingQRCode;

    // ZXing QRCode port to Delphi, by Debenu Pty Ltd
    // www.debenu.com

    // Original copyright notice
    (*
     * Copyright 2008 ZXing authors
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *      http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     *)

    interface

    type
      TQRCodeEncoding = (qrAuto, qrNumeric, qrAlphanumeric, qrISO88591, qrUTF8NoBOM, qrUTF8BOM);
      T2DBooleanArray = array of array of Boolean;

      TDelphiZXingQRCode = class
      protected
        FData: WideString;
        FRows: Integer;
        FColumns: Integer;
        FEncoding: TQRCodeEncoding;
        FQuietZone: Integer;
        FElements: T2DBooleanArray;
        FErrorCorrectionLevel: integer;
        procedure SetEncoding(NewEncoding: TQRCodeEncoding);
        procedure SetData(const NewData: WideString);
        procedure SetQuietZone(NewQuietZone: Integer);
        procedure SetErrorCorrectionLevel(value: integer);
        function GetIsBlack(Row, Column: Integer): Boolean;
        procedure Update;
      public
        constructor Create;
        property Data: WideString read FData write SetData;
        property Encoding: TQRCodeEncoding read FEncoding write SetEncoding;
        property ErrorCorrectionLevel: integer read fErrorCorrectionLevel write SetErrorCorrectionLevel;
        property QuietZone: Integer read FQuietZone write SetQuietZone;
        property Rows: Integer read FRows;
        property Columns: Integer read FColumns;
        property IsBlack[Row, Column: Integer]: Boolean read GetIsBlack;
      end;

    implementation

    uses
      SysUtils,
      contnrs, Math, Classes;

    type
      TByteArray = array of Byte;
      T2DByteArray = array of array of Byte;
      TIntegerArray = array of Integer;

    // File too large for Whosebug: Deleted unchanged lines.

    { TErrorCorrectionLevel }

    procedure TErrorCorrectionLevel.Assign(Source: TErrorCorrectionLevel);
    begin
      Self.fOrdinal := Source.FOrdinal;
    end;

    constructor TErrorCorrectionLevel.Create(ordinalValue: integer);
    begin

      fOrdinal:=0;
      if (ordinalValue >= 0) and (ordinalValue <=3) then
        fOrdinal:=ordinalValue;
    end;

    function TErrorCorrectionLevel.GetBits: integer;
    begin
      if fOrdinal = 0 then  // level L
        result:=1
      else
      if fOrdinal = 1 then  // level M
        result:=0
      else
      if fOrdinal = 2 then  // level Q
        result:=3
      else
      if fOrdinal = 3 then  // level H
        result:=2
      else
        result:=1;
    end;


    // File too large for Whosebug: Deleted unchanged lines.

    procedure TDelphiZXingQRCode.SetErrorCorrectionLevel(value: integer);
    begin
      if (value < 0) or (value > 3) then
        raise Exception.Create('invalid error correction value. must be in range 0..3.');

      if value <> fErrorCorrectionLevel then
      begin
        FErrorCorrectionLevel:=value;
        Update;
      end;
    end;

    procedure TDelphiZXingQRCode.SetQuietZone(NewQuietZone: Integer);
    begin
      if ((FQuietZone <> NewQuietZone) and (NewQuietZone >= 0) and (NewQuietZone <= 100)) then
      begin
        FQuietZone := NewQuietZone;
        Update;
      end;
    end;

    procedure TDelphiZXingQRCode.Update;
    begin
      FElements := GenerateQRCode(FData, Ord(FEncoding), FErrorCorrectionLevel);
      FRows := Length(FElements) + FQuietZone * 2;
      FColumns := FRows;
    end;
    end.

由 DelphiZXingQRCode 编码的 QR 码无法通过 ErrorCorrectionLevel > Low 解码

QR Codes encoded by DelphiZXingQRCode not decodable with ErrorCorrectionLevel > Low

delphi

qr-code

zxing