DLLSample/ExpertSample.cpp

   1 //+------------------------------------------------------------------+
   2 //|                                              Sample DLL for MQL4 |
   3 //|                 Copyright © 2004-2006, MetaQuotes Software Corp. |
   4 //|                                        http://www.metaquotes.net |
   5 //+------------------------------------------------------------------+
   6 #define WIN32_LEAN_AND_MEAN  // Exclude rarely-used stuff from Windows headers
   7 #include <windows.h>
   8 #include <stdlib.h>
   9 #include <stdio.h>
  10 //----
  11 #define MT4_EXPFUNC __declspec(dllexport)
  12 //+------------------------------------------------------------------+
  13 //|                                                                  |
  14 //+------------------------------------------------------------------+
  15 #pragma pack(push,1)
  16 struct RateInfo
  17   {
  18    unsigned int      ctm;
  19    double            open;
  20    double            low;
  21    double            high;
  22    double            close;
  23    double            vol;
  24   };
  25 #pragma pack(pop)
  26 //----
  27 struct MqlStr
  28   {
  29    int               len;
  30    char             *string;
  31   };
  32 static int CompareMqlStr(const void *left,const void *right);
  33 //+------------------------------------------------------------------+
  34 //|                                                                  |
  35 //+------------------------------------------------------------------+
  36 BOOL APIENTRY DllMain(HANDLE hModule,DWORD ul_reason_for_call,LPVOID lpReserved)
  37   {
  38 //----
  39    switch(ul_reason_for_call)
  40      {
  41       case DLL_PROCESS_ATTACH:
  42       case DLL_THREAD_ATTACH:
  43       case DLL_THREAD_DETACH:
  44       case DLL_PROCESS_DETACH:
  45          break;
  46      }
  47 //----
  48    return(TRUE);
  49   }
  50 //+------------------------------------------------------------------+
  51 //|                                                                  |
  52 //+------------------------------------------------------------------+
  53 MT4_EXPFUNC int __stdcall GetIntValue(const int ipar)
  54   {
  55    printf("GetIntValue takes %d\n",ipar);
  56    return(ipar);
  57   }
  58 //+------------------------------------------------------------------+
  59 //|                                                                  |
  60 //+------------------------------------------------------------------+
  61 MT4_EXPFUNC double __stdcall GetDoubleValue(const double dpar)
  62   {
  63    printf("GetDoubleValue takes %.8lf\n",dpar);
  64    return(dpar);
  65   }
  66 //+------------------------------------------------------------------+
  67 //|                                                                  |
  68 //+------------------------------------------------------------------+
  69 MT4_EXPFUNC char* __stdcall GetStringValue(char *spar)
  70   {
  71    printf("GetDoubleValue takes \"%s\"\n",spar);
  72    return(spar);
  73   }
  74 //+------------------------------------------------------------------+
  75 //|                                                                  |
  76 //+------------------------------------------------------------------+
  77 MT4_EXPFUNC double __stdcall GetArrayItemValue(const double *arr,const int arraysize,const int nitem)
  78   {
  79 //----
  80    if(arr==NULL)
  81      {
  82       printf("GetArrayItemValue: NULL array\n");
  83       return(0.0);
  84      }
  85    if(arraysize<=0)
  86      {
  87       printf("GetArrayItemValue: wrong arraysize (%d)\n", arraysize);
  88       return(0.0);
  89      }
  90    if(nitem<0 || nitem>=arraysize)
  91      {
  92       printf("GetArrayItemValue: wrong item number (%d)\n", nitem);
  93       return(0.0);
  94      }
  95 //----
  96    return(arr[nitem]);
  97   }
  98 //+------------------------------------------------------------------+
  99 //|                                                                  |
 100 //+------------------------------------------------------------------+
 101 MT4_EXPFUNC BOOL __stdcall SetArrayItemValue(double *arr,const int arraysize,const int nitem,const double value)
 102   {
 103 //----
 104    if(arr==NULL)
 105      {
 106       printf("GetArrayItemValue: NULL array\n");
 107       return(FALSE);
 108      }
 109    if(arraysize<=0)
 110      {
 111       printf("GetArrayItemValue: wrong arraysize (%d)\n", arraysize);
 112       return(FALSE);
 113      }
 114    if(nitem<0 || nitem>=arraysize)
 115      {
 116       printf("GetArrayItemValue: wrong item number (%d)\n", nitem);
 117       return(FALSE);
 118      }
 119 //----
 120    arr[nitem]=value;
 121    return(TRUE);
 122   }
 123 //+------------------------------------------------------------------+
 124 //|                                                                  |
 125 //+------------------------------------------------------------------+
 126 MT4_EXPFUNC double __stdcall GetRatesItemValue(const RateInfo* rates,const int rates_total,const int shift,const int nrate)
 127   {
 128 //----
 129    if(rates==NULL)
 130      {
 131       printf("GetRatesItemValue: NULL array\n");
 132       return(0.0);
 133      }
 134 //----
 135    if(rates_total<0)
 136      {
 137       printf("GetRatesItemValue: wrong rates_total number (%d)\n", rates_total);
 138       return(0.0);
 139      }
 140 //----
 141    if(shift<0 || shift>=rates_total)
 142      {
 143       printf("GetRatesItemValue: wrong shift number (%d)\n", shift);
 144       return(0.0);
 145      }
 146 //----
 147    if(nrate<0 || nrate>5)
 148      {
 149       printf("GetRatesItemValue: wrong rate index (%d)\n", nrate);
 150       return(0.0);
 151      }
 152 //----
 153    int nitem=rates_total-1-shift;
 154    switch(nrate)
 155      {
 156       case 0: return double(rates[nitem].ctm);
 157       case 1: return rates[nitem].open;
 158       case 2: return rates[nitem].low;
 159       case 3: return rates[nitem].high;
 160       case 4: return rates[nitem].close;
 161       case 5: return rates[nitem].vol;
 162      }
 163 //----
 164    return(0.0);
 165   }
 166 //+------------------------------------------------------------------+
 167 //|                                                                  |
 168 //+------------------------------------------------------------------+
 169 MT4_EXPFUNC int __stdcall SortStringArray(MqlStr *arr,const int arraysize)
 170   {
 171 //----
 172    if(arr==NULL)
 173      {
 174       printf("SortStringArray: NULL array\n");
 175       return(-1);
 176      }
 177    if(arraysize<=0)
 178      {
 179       printf("SortStringArray: wrong arraysize (%d)\n", arraysize);
 180       return(-1);
 181      }
 182 //----
 183    qsort(arr,arraysize,sizeof(MqlStr),CompareMqlStr);
 184 //----
 185    return(arraysize);
 186   }
 187 //+------------------------------------------------------------------+
 188 //|                                                                  |
 189 //+------------------------------------------------------------------+
 190 MT4_EXPFUNC int __stdcall ProcessStringArray(MqlStr *arr,const int arraysize)
 191   {
 192    int   len1,len2;
 193 //----
 194    if(arr==NULL)
 195      {
 196       printf("ProcessStringArray: NULL array\n");
 197       return(-1);
 198      }
 199    if(arraysize<=0)
 200      {
 201       printf("ProcessStringArray: wrong arraysize (%d)\n", arraysize);
 202       return(-1);
 203      }
 204 //----
 205    for(int i=0; i<arraysize-1; i++)
 206      {
 207       if(arr[i].string==NULL) len1=0;
 208       else len1=strlen(arr[i].string);
 209       if(arr[i+1].string==NULL) len2=0;
 210       else len2=strlen(arr[i+1].string);
 211       //---- uninitialized string
 212       if(arr[i+1].string==NULL) continue;
 213       //---- destination string is uninitialized and cannot be allocated within dll
 214       if(arr[i].string==NULL)   continue;
 215       //---- memory piece is less than needed and cannot be reallocated within dll
 216       if(arr[i].len<len1+len2)  continue;
 217       //---- final processing
 218       strcat(arr[i].string,arr[i+1].string);
 219      }
 220 //----
 221    return(arraysize);
 222   }
 223 //+------------------------------------------------------------------+
 224 //|                                                                  |
 225 //+------------------------------------------------------------------+
 226 int CompareMqlStr(const void *left,const void *right)
 227   {
 228    MqlStr *leftstr=(MqlStr *)left;
 229    MqlStr *rightstr=(MqlStr *)right;
 230 //----
 231    if(leftstr->string==NULL) return(-1);
 232    if(rightstr->string==NULL) return(1);
 233 //----
 234    return(strcmp(leftstr->string,rightstr->string));
 235   }
 236 //+------------------------------------------------------------------+