c# - An item with the same key has already been added in Dictionary -

i working on sql clr application, after integrating sql, getting error (for english it's working problems while adding unicodes dictionory):

**msg 6522, level 16, state 2, line 1 .net framework error occurred during execution of user-defined routine or     aggregate "sqlcompare":  system.argumentexception: item same key has been added. system.argumentexception:     @ system.throwhelper.throwargumentexception(exceptionresource resource)    @ system.collections.generic.dictionary`2.insert(tkey key, tvalue value,      boolean add)    @ system.collections.generic.dictionary`2.add(tkey key, tvalue value)    @ translate_class_num..ctor()    @ stringpercentagecompare..ctor()    @ userdefinedfunctions.sqlcomparison()**   here code in c# private   dictionary<string, string> mydictionary; //private string[,] myarray;  public translate_class_num() {     mydictionary.add("?", "01");     mydictionary.add("?", "02");     mydictionary.add("?", "03");     mydictionary.add("?", "04");     mydictionary.add("?", "05") } 

and in sql server code create assembly dbdb_deduplication authorization dbo 'e:\projects\dbdb_deduplication\dbdb_deduplication\obj\debug\dbdb_deduplication.dll' permission_set = safe go

create function sqlcompare() returns nvarchar(50) external name dbdb_deduplication.userdefinedfunctions.sqlcomparison; go

select dbo.sqlcompare(); go

thanks in advance

this code works fine me:

dictionary<string, string> dict = new dictionary<string, string>(); dict.add("ಅ","01"); dict.add("ಇ","02"); 

as tried explain before in comments, unicode string must not passing through compiler in way expect. can due c# source file being saved ascii encoding or other non-unicode supporting encoding. guarantee results, use c# unicode literal encoding (u+0000 u+ffff).

if don't know how equivalent unicode escape sequence, can use code:

static string encodenonasciicharacters( string value ) {     stringbuilder sb = new stringbuilder();     foreach( char c in value ) {         if( c > 127 ) {             // character big ascii             string encodedvalue = "\\u" + ((int) c).tostring( "x4" );             sb.append( encodedvalue );         }         else {             sb.append( c );         }     }     return sb.tostring(); }  console.writeline(encodenonasciicharacters("ಅ")); \u0c85 console.writeline(encodenonasciicharacters("ಇ")); \u0c87 

so can write safer version of source code as:

dictionary<string, string> dict = new dictionary<string, string>(); dict.add("\u0c85","01"); dict.add("\u0c87","02");