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| 1 | +using System; |
| 2 | +using System.Text; |
| 3 | + |
| 4 | +namespace GenCode128 |
| 5 | +{ |
| 6 | + public enum CodeSet |
| 7 | + { |
| 8 | + CodeA |
| 9 | + ,CodeB |
| 10 | + // ,CodeC // not supported |
| 11 | + } |
| 12 | + |
| 13 | + /// <summary> |
| 14 | + /// Represent the set of code values to be output into barcode form |
| 15 | + /// </summary> |
| 16 | + public class Code128Content |
| 17 | + { |
| 18 | + private int[] mCodeList; |
| 19 | + |
| 20 | + /// <summary> |
| 21 | + /// Create content based on a string of ASCII data |
| 22 | + /// </summary> |
| 23 | + /// <param name="AsciiData">the string that should be represented</param> |
| 24 | + public Code128Content( string AsciiData ) |
| 25 | + { |
| 26 | + mCodeList = StringToCode128(AsciiData); |
| 27 | + } |
| 28 | + |
| 29 | + /// <summary> |
| 30 | + /// Provides the Code128 code values representing the object's string |
| 31 | + /// </summary> |
| 32 | + public int[] Codes |
| 33 | + { |
| 34 | + get |
| 35 | + { |
| 36 | + return mCodeList; |
| 37 | + } |
| 38 | + } |
| 39 | + |
| 40 | + /// <summary> |
| 41 | + /// Transform the string into integers representing the Code128 codes |
| 42 | + /// necessary to represent it |
| 43 | + /// </summary> |
| 44 | + /// <param name="AsciiData">String to be encoded</param> |
| 45 | + /// <returns>Code128 representation</returns> |
| 46 | + private int[] StringToCode128( string AsciiData ) |
| 47 | + { |
| 48 | + // turn the string into ascii byte data |
| 49 | + byte[] asciiBytes = Encoding.ASCII.GetBytes( AsciiData ); |
| 50 | + |
| 51 | + // decide which codeset to start with |
| 52 | + Code128Code.CodeSetAllowed csa1 = asciiBytes.Length>0 ? Code128Code.CodesetAllowedForChar( asciiBytes[0] ) : Code128Code.CodeSetAllowed.CodeAorB; |
| 53 | + Code128Code.CodeSetAllowed csa2 = asciiBytes.Length>0 ? Code128Code.CodesetAllowedForChar( asciiBytes[1] ) : Code128Code.CodeSetAllowed.CodeAorB; |
| 54 | + CodeSet currcs = GetBestStartSet(csa1,csa2); |
| 55 | + |
| 56 | + // set up the beginning of the barcode |
| 57 | + System.Collections.ArrayList codes = new System.Collections.ArrayList(asciiBytes.Length + 3); // assume no codeset changes, account for start, checksum, and stop |
| 58 | + codes.Add(Code128Code.StartCodeForCodeSet(currcs)); |
| 59 | + |
| 60 | + // add the codes for each character in the string |
| 61 | + for (int i = 0; i < asciiBytes.Length; i++) |
| 62 | + { |
| 63 | + int thischar = asciiBytes[i]; |
| 64 | + int nextchar = asciiBytes.Length>(i+1) ? asciiBytes[i+1] : -1; |
| 65 | + |
| 66 | + codes.AddRange( Code128Code.CodesForChar(thischar, nextchar, ref currcs) ); |
| 67 | + } |
| 68 | + |
| 69 | + // calculate the check digit |
| 70 | + int checksum = (int)(codes[0]); |
| 71 | + for (int i = 1; i < codes.Count; i++) |
| 72 | + { |
| 73 | + checksum += i * (int)(codes[i]); |
| 74 | + } |
| 75 | + codes.Add( checksum % 103 ); |
| 76 | + |
| 77 | + codes.Add( Code128Code.StopCode() ); |
| 78 | + |
| 79 | + int[] result = codes.ToArray(typeof(int)) as int[]; |
| 80 | + return result; |
| 81 | + } |
| 82 | + |
| 83 | + /// <summary> |
| 84 | + /// Determines the best starting code set based on the the first two |
| 85 | + /// characters of the string to be encoded |
| 86 | + /// </summary> |
| 87 | + /// <param name="csa1">First character of input string</param> |
| 88 | + /// <param name="csa2">Second character of input string</param> |
| 89 | + /// <returns>The codeset determined to be best to start with</returns> |
| 90 | + private CodeSet GetBestStartSet( Code128Code.CodeSetAllowed csa1, Code128Code.CodeSetAllowed csa2 ) |
| 91 | + { |
| 92 | + int vote = 0; |
| 93 | + |
| 94 | + vote += (csa1==Code128Code.CodeSetAllowed.CodeA) ? 1 : 0; |
| 95 | + vote += (csa1==Code128Code.CodeSetAllowed.CodeB) ? -1 : 0; |
| 96 | + vote += (csa2==Code128Code.CodeSetAllowed.CodeA) ? 1 : 0; |
| 97 | + vote += (csa2==Code128Code.CodeSetAllowed.CodeB) ? -1 : 0; |
| 98 | + |
| 99 | + return (vote>0) ? CodeSet.CodeA : CodeSet.CodeB; // ties go to codeB due to my own prejudices |
| 100 | + } |
| 101 | + } |
| 102 | + |
| 103 | + /// <summary> |
| 104 | + /// Static tools for determining codes for individual characters in the content |
| 105 | + /// </summary> |
| 106 | + public static class Code128Code |
| 107 | + { |
| 108 | + #region Constants |
| 109 | + |
| 110 | + private const int cSHIFT = 98; |
| 111 | + private const int cCODEA = 101; |
| 112 | + private const int cCODEB = 100; |
| 113 | + |
| 114 | + private const int cSTARTA = 103; |
| 115 | + private const int cSTARTB = 104; |
| 116 | + private const int cSTOP = 106; |
| 117 | + |
| 118 | + #endregion |
| 119 | + |
| 120 | + /// <summary> |
| 121 | + /// Get the Code128 code value(s) to represent an ASCII character, with |
| 122 | + /// optional look-ahead for length optimization |
| 123 | + /// </summary> |
| 124 | + /// <param name="CharAscii">The ASCII value of the character to translate</param> |
| 125 | + /// <param name="LookAheadAscii">The next character in sequence (or -1 if none)</param> |
| 126 | + /// <param name="CurrCodeSet">The current codeset, that the returned codes need to follow; |
| 127 | + /// if the returned codes change that, then this value will be changed to reflect it</param> |
| 128 | + /// <returns>An array of integers representing the codes that need to be output to produce the |
| 129 | + /// given character</returns> |
| 130 | + public static int[] CodesForChar(int CharAscii, int LookAheadAscii, ref CodeSet CurrCodeSet) |
| 131 | + { |
| 132 | + int[] result; |
| 133 | + int shifter = -1; |
| 134 | + |
| 135 | + if (!CharCompatibleWithCodeset(CharAscii,CurrCodeSet)) |
| 136 | + { |
| 137 | + // if we have a lookahead character AND if the next character is ALSO not compatible |
| 138 | + if ( (LookAheadAscii != -1) && !CharCompatibleWithCodeset(LookAheadAscii,CurrCodeSet) ) |
| 139 | + { |
| 140 | + // we need to switch code sets |
| 141 | + switch (CurrCodeSet) |
| 142 | + { |
| 143 | + case CodeSet.CodeA: |
| 144 | + shifter = cCODEB; |
| 145 | + CurrCodeSet = CodeSet.CodeB; |
| 146 | + break; |
| 147 | + case CodeSet.CodeB: |
| 148 | + shifter = cCODEA; |
| 149 | + CurrCodeSet = CodeSet.CodeA; |
| 150 | + break; |
| 151 | + } |
| 152 | + } |
| 153 | + else |
| 154 | + { |
| 155 | + // no need to switch code sets, a temporary SHIFT will suffice |
| 156 | + shifter = cSHIFT; |
| 157 | + } |
| 158 | + } |
| 159 | + |
| 160 | + if (shifter!=-1) |
| 161 | + { |
| 162 | + result = new int[2]; |
| 163 | + result[0] = shifter; |
| 164 | + result[1] = CodeValueForChar(CharAscii); |
| 165 | + } |
| 166 | + else |
| 167 | + { |
| 168 | + result = new int[1]; |
| 169 | + result[0] = CodeValueForChar(CharAscii); |
| 170 | + } |
| 171 | + |
| 172 | + return result; |
| 173 | + } |
| 174 | + |
| 175 | + /// <summary> |
| 176 | + /// Tells us which codesets a given character value is allowed in |
| 177 | + /// </summary> |
| 178 | + /// <param name="CharAscii">ASCII value of character to look at</param> |
| 179 | + /// <returns>Which codeset(s) can be used to represent this character</returns> |
| 180 | + public static CodeSetAllowed CodesetAllowedForChar(int CharAscii) |
| 181 | + { |
| 182 | + if (CharAscii>=32 && CharAscii<=95) |
| 183 | + { |
| 184 | + return CodeSetAllowed.CodeAorB; |
| 185 | + } |
| 186 | + else |
| 187 | + { |
| 188 | + return (CharAscii<32) ? CodeSetAllowed.CodeA : CodeSetAllowed.CodeB; |
| 189 | + } |
| 190 | + } |
| 191 | + |
| 192 | + /// <summary> |
| 193 | + /// Determine if a character can be represented in a given codeset |
| 194 | + /// </summary> |
| 195 | + /// <param name="CharAscii">character to check for</param> |
| 196 | + /// <param name="currcs">codeset context to test</param> |
| 197 | + /// <returns>true if the codeset contains a representation for the ASCII character</returns> |
| 198 | + public static bool CharCompatibleWithCodeset(int CharAscii, CodeSet currcs) |
| 199 | + { |
| 200 | + CodeSetAllowed csa = CodesetAllowedForChar(CharAscii); |
| 201 | + return csa==CodeSetAllowed.CodeAorB |
| 202 | + || (csa==CodeSetAllowed.CodeA && currcs==CodeSet.CodeA) |
| 203 | + || (csa==CodeSetAllowed.CodeB && currcs==CodeSet.CodeB); |
| 204 | + } |
| 205 | + |
| 206 | + /// <summary> |
| 207 | + /// Gets the integer code128 code value for a character (assuming the appropriate code set) |
| 208 | + /// </summary> |
| 209 | + /// <param name="CharAscii">character to convert</param> |
| 210 | + /// <returns>code128 symbol value for the character</returns> |
| 211 | + public static int CodeValueForChar(int CharAscii) |
| 212 | + { |
| 213 | + return (CharAscii>=32) ? CharAscii-32 : CharAscii+64; |
| 214 | + } |
| 215 | + |
| 216 | + /// <summary> |
| 217 | + /// Return the appropriate START code depending on the codeset we want to be in |
| 218 | + /// </summary> |
| 219 | + /// <param name="cs">The codeset you want to start in</param> |
| 220 | + /// <returns>The code128 code to start a barcode in that codeset</returns> |
| 221 | + public static int StartCodeForCodeSet(CodeSet cs) |
| 222 | + { |
| 223 | + return cs==CodeSet.CodeA ? cSTARTA : cSTARTB; |
| 224 | + } |
| 225 | + |
| 226 | + /// <summary> |
| 227 | + /// Return the Code128 stop code |
| 228 | + /// </summary> |
| 229 | + /// <returns>the stop code</returns> |
| 230 | + public static int StopCode() |
| 231 | + { |
| 232 | + return cSTOP; |
| 233 | + } |
| 234 | + |
| 235 | + /// <summary> |
| 236 | + /// Indicates which code sets can represent a character -- CodeA, CodeB, or either |
| 237 | + /// </summary> |
| 238 | + public enum CodeSetAllowed |
| 239 | + { |
| 240 | + CodeA, |
| 241 | + CodeB, |
| 242 | + CodeAorB |
| 243 | + } |
| 244 | + |
| 245 | + } |
| 246 | +} |
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