CComboBox

CComboBox 是 ComboBox 复合控件之中的类 (含依赖控件)。

描述

ComboBox 由列表框构成, 结合静态控件, 目的用于选择。当用户选择下拉键头时, 控件的列表框部分可以向下展开。

声明

class CComboBox : public CWndContainer

标称库文件

#include <Controls\ComboBox.mqh>

继承体系

CObject

CWnd

CWndContainer

CComboBox

下面提供的代码的结果：

ControlsComboBox

类方法

创建
创建	创建控件
图表事件处理器
OnEvent	所有图表事件的句柄
添加
AddItem	添加一个项目
设置
ListViewItems	设置显示在控件上的项目数量
数据
Select	按照索引选择当前列表项
SelectByText	按照文本选择当前列表项
SelectByValue	按照值选择当前列表项
只读数据
数值	获取当前列表项的值
依赖控件
CreateEdit	创建依赖控件 (编辑)
CreateButton	创建依赖控件 (按钮)
CreateList	创建依赖控件 (列表视野)
依赖控件事件处理器
OnClickEdit	“点击编辑” 事件处理器 (虚函数)
OnClickButton	“点击按钮” 事件处理器 (虚函数)
OnChangeList	“改变列表” 事件处理器 (虚函数)
显示/隐藏
ListShow	显示项目列表
ListHide	隐藏项目列表

方法继承自类 CWnd

: Name, ControlsTotal, Control, Rect, Left, Left, Top, Top, Right, Right, Bottom, Bottom, Width, Width, Height, Height, Size, Size, Size, Contains, Contains, Alignment, Align, Id, IsEnabled, IsVisible, Visible, IsActive, Activate, Deactivate, StateFlags, StateFlags, StateFlagsSet, StateFlagsReset, PropFlags, PropFlags, PropFlagsSet, PropFlagsReset, MouseX, MouseX, MouseY, MouseY, MouseFlags, MouseFlags, MouseFocusKill, BringToTop

方法继承自类 CWndContainer

: Destroy, OnMouseEvent, ControlsTotal, Control, ControlFind, MouseFocusKill, Add, Add, Delete, Delete, Move, Move, Shift, Id, Enable, Disable, Hide

创建组合框控制面板的示例：

//+------------------------------------------------------------------+
//|                                             ControlsComboBox.mq5 |
//|                        Copyright 2015, MetaQuotes Software Corp. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2015, MetaQuotes Software Corp."
#property link      "https://www.mql5.com"
#property version   "1.00"
#property description "Control Panels and Dialogs. Demonstration class CComboBox"
#include <Controls\Dialog.mqh>
#include <Controls\ComboBox.mqh>
//+------------------------------------------------------------------+
//| defines                                                          |
//+------------------------------------------------------------------+
//--- indents and gaps
#define INDENT_LEFT                         (11)      // indent from left (with allowance for border width)
#define INDENT_TOP                          (11)      // indent from top (with allowance for border width)
#define INDENT_RIGHT                        (11)      // indent from right (with allowance for border width)
#define INDENT_BOTTOM                       (11)      // indent from bottom (with allowance for border width)
#define CONTROLS_GAP_X                      (5)       // gap by X coordinate
#define CONTROLS_GAP_Y                      (5)       // gap by Y coordinate
//--- for buttons
#define BUTTON_WIDTH                        (100)     // size by X coordinate
#define BUTTON_HEIGHT                       (20)      // size by Y coordinate
//--- for the indication area
#define EDIT_HEIGHT                         (20)      // size by Y coordinate
//--- for group controls
#define GROUP_WIDTH                         (150)     // size by X coordinate
#define LIST_HEIGHT                         (179)     // size by Y coordinate
#define RADIO_HEIGHT                        (56)      // size by Y coordinate
#define CHECK_HEIGHT                        (93)      // size by Y coordinate
//+------------------------------------------------------------------+
//| Class CControlsDialog                                            |
//| Usage: main dialog of the Controls application                   |
//+------------------------------------------------------------------+
class CControlsDialog : public CAppDialog
  {
private:
   CComboBox         m_combo_box;;                    // CComboBox object

public:
                     CControlsDialog(void);
                    ~CControlsDialog(void);
   //--- create
   virtual bool      Create(const long chart,const string name,const int subwin,const int x1,const int y1,const int x2,const int y2);
   //--- chart event handler
   virtual bool      OnEvent(const int id,const long &lparam,const double &dparam,const string &sparam);

protected:
   //--- create dependent controls
   bool              CreateComboBox(void);
   //--- handlers of the dependent controls events
   void              OnChangeComboBox(void);
  };
//+------------------------------------------------------------------+
//| Event Handling                                                   |
//+------------------------------------------------------------------+
EVENT_MAP_BEGIN(CControlsDialog)
ON_EVENT(ON_CHANGE,m_combo_box,OnChangeComboBox)
EVENT_MAP_END(CAppDialog)
//+------------------------------------------------------------------+
//| Constructor                                                      |
//+------------------------------------------------------------------+
CControlsDialog::CControlsDialog(void)
  {
  }
//+------------------------------------------------------------------+
//| Destructor                                                       |
//+------------------------------------------------------------------+
CControlsDialog::~CControlsDialog(void)
  {
  }
//+------------------------------------------------------------------+
//| Create                                                           |
//+------------------------------------------------------------------+
bool CControlsDialog::Create(const long chart,const string name,const int subwin,const int x1,const int y1,const int x2,const int y2)
  {
   if(!CAppDialog::Create(chart,name,subwin,x1,y1,x2,y2))
      return(false);
//--- create dependent controls
   if(!CreateComboBox())
      return(false);
//--- succeed
   return(true);
  }
//+------------------------------------------------------------------+
//| Create the "ComboBox" element                                    |
//+------------------------------------------------------------------+
bool CControlsDialog::CreateComboBox(void)
  {
//--- coordinates
   int x1=INDENT_LEFT;
   int y1=INDENT_TOP+(EDIT_HEIGHT+CONTROLS_GAP_Y)+
          (BUTTON_HEIGHT+CONTROLS_GAP_Y)+
          (EDIT_HEIGHT+CONTROLS_GAP_Y);
   int x2=x1+GROUP_WIDTH;
   int y2=y1+EDIT_HEIGHT;
//--- create
   if(!m_combo_box.Create(m_chart_id,m_name+"ComboBox",m_subwin,x1,y1,x2,y2))
      return(false);
   if(!Add(m_combo_box))
      return(false);
//--- fill out with strings
   for(int i=0;i<16;i++)
      if(!m_combo_box.ItemAdd("Item "+IntegerToString(i)))
         return(false);
//--- succeed
   return(true);
  }
//+------------------------------------------------------------------+
//| Event handler                                                    |
//+------------------------------------------------------------------+
void CControlsDialog::OnChangeComboBox(void)
  {
   Comment(__FUNCTION__+" \""+m_combo_box.Select()+"\"");
  }
//+------------------------------------------------------------------+
//| Global Variables                                                 |
//+------------------------------------------------------------------+
CControlsDialog ExtDialog;
//+------------------------------------------------------------------+
//| Expert initialization function                                   |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- create application dialog
   if(!ExtDialog.Create(0,"Controls",0,40,40,380,344))
      return(INIT_FAILED);
//--- run application
   ExtDialog.Run();
//--- succeed
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
//---
   Comment("");
//--- destroy dialog
   ExtDialog.Destroy(reason);
  }
//+------------------------------------------------------------------+
//| Expert chart event function                                      |
//+------------------------------------------------------------------+
void OnChartEvent(const int id,         // event ID
                  const long& lparam,   // event parameter of the long type
                  const double& dparam, // event parameter of the double type
                  const string& sparam) // event parameter of the string type
  {
   ExtDialog.ChartEvent(id,lparam,dparam,sparam);
  }