DoubleToStringFunction  ValuesFunctionFormat()

void  ValuesFunctionFormat(
   DoubleToStringFunction  func      // 将数值转为字符串的函数
   )

//+------------------------------------------------------------------+
//|                                              DateAxisGraphic.mq5 |
//|                        Copyright 2016, MetaQuotes Software Corp. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#include <Graphics\Graphic.mqh>
//--- array for store values
double arrX[];
double arrY[];
//+------------------------------------------------------------------+
//| 创建X轴值的自定义函数                                               |
//+------------------------------------------------------------------+
string TimeFormat(double x,void *cbdata)
  {
   return(TimeToString((datetime)arrX[ArraySize(arrX)-(int)x-1]));
  }
//+------------------------------------------------------------------+
void OnStart()
  {
   MqlRates rates[];
   CopyRates(Symbol(),Period(),0,100,rates);
   ArraySetAsSeries(rates,true);
   int size=ArraySize(rates);
   ArrayResize(arrX,size);
   ArrayResize(arrY,size);
   for(int i=0; i<size;++i)
     {
      arrX[i]=(double)rates[i].time;
      arrY[i]=rates[i].close;
     }
//--- create graphic
   CGraphic graphic;
   if(!graphic.Create(0,"DateAxisGraphic",0,30,30,780,380))
     {
      graphic.Attach(0,"DateAxisGraphic");
     }
//--- create curve
   CCurve *curve=graphic.CurveAdd(arrY,CURVE_LINES);
//--- 获得X轴 
   CAxis *xAxis=graphic.XAxis();
//--- 设置 X 轴属性 
   xAxis.AutoScale(false);
   xAxis.Type(AXIS_TYPE_CUSTOM);
   xAxis.ValuesFunctionFormat(TimeFormat);
   xAxis.DefaultStep(20.0);
//--- plot 
   graphic.CurvePlotAll();
   graphic.Update();
  }