Change text in a CLabel
febrero59:
I keep building my panel from scratch and, never have, I'm stumbling on pretty much everything.
I am starting with Class CControlsDialog. I've done well with buttons, labels, and edit boxes.
But I have a problem with https://www.mql5.com/en/docs/standardlibrary/controls/clabel.
I need to change the label text, but I can't get the syntax right and I can't find a suitable example on the net.
Can you give me a link or explanation about it?
Thank you very much.
it is quite clear in the documentation but post your code attempt with the code button </> if you need some help
Documentation on MQL5: Standard Library / Panels and Dialogs / CLabel
- www.mql5.com
CLabel - Panels and Dialogs - Standard Library - MQL5 Reference - Reference on algorithmic/automated trading language for MetaTrader 5
#include <Controls\Dialog.mqh> #include <Controls\Label.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: CLabel m_label; // CLabel 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 CreateLabel(void); //--- handlers of the dependent controls events void OnClickLabel(void); }; //+------------------------------------------------------------------+ //| Event Handling | //+------------------------------------------------------------------+ EVENT_MAP_BEGIN(CControlsDialog) 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(!CreateLabel()) return(false); //--- succeed return(true); } //+------------------------------------------------------------------+ //| Create the "CLabel" | //+------------------------------------------------------------------+ bool CControlsDialog::CreateLabel(void) { //--- coordinates int x1=INDENT_RIGHT; int y1=INDENT_TOP+CONTROLS_GAP_Y; int x2=x1+100; int y2=y1+20; //--- create if(!m_label.Create(m_chart_id,m_name+"Label",m_subwin,x1,y1,x2,y2)) return(false); if(!m_label.Text("Label123456")) return(false); if(!Add(m_label)) return(false); Comment(m_label.Text()); //--- succeed return(true); } //+------------------------------------------------------------------+ //| 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); // Comment(label, "-", dparam); } void OnTick() { double Ask=NormalizeDouble(SymbolInfoDouble(_Symbol,SYMBOL_ASK),_Digits); // ObjectSetString(0,label,OBJPROP_TEXT, (string)Ask); // Label.TextChange(0,label,(string)Ask)); label.SetText(Ask); }
It should be very easy, but I don't know how to pass the Ask price to the label...
Use
label.Text(DoubleToString(Ask,Digits()));
Excuse me Vladimir, what do I have to do so that I don't get the error: " 'label' - undeclared identifier "?
febrero59 # :
Excuse me Vladimir, what do I have to do so that I don't get the error: " 'label' - undeclared identifier "?
Excuse me Vladimir, what do I have to do so that I don't get the error: " 'label' - undeclared identifier "?
Note that you have declared an object inside the panel class:
class CControlsDialog : public CAppDialog { private: CLabel m_label; // CLabel object
Now you need to organize a method by which your adviser will communicate with the panel class.
One more request - attach the code as a file (using the button 
), so it will be more convenient for me to download your code.
Example:
//+------------------------------------------------------------------+ //| Test Panel.mq5 | //| Copyright © 2022, Vladimir Karputov | //| https://www.mql5.com/en/users/barabashkakvn | //+------------------------------------------------------------------+ #property copyright "Copyright © 2022, Vladimir Karputov" #property link "https://www.mql5.com/en/users/barabashkakvn" #property version "1.00" //--- input parameters input int Input1=9; #include <Controls\Dialog.mqh> #include <Controls\Label.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: CLabel m_label; // CLabel 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); //--- Change text virtual void ChangeText(const string text) {m_label.Text(text);} protected: //--- create dependent controls bool CreateLabel(void); //--- handlers of the dependent controls events void OnClickLabel(void); }; //+------------------------------------------------------------------+ //| Event Handling | //+------------------------------------------------------------------+ EVENT_MAP_BEGIN(CControlsDialog) //+------------------------------------------------------------------+ //| | //+------------------------------------------------------------------+ 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(!CreateLabel()) return(false); //--- succeed return(true); } //+------------------------------------------------------------------+ //| Create the "CLabel" | //+------------------------------------------------------------------+ bool CControlsDialog::CreateLabel(void) { //--- coordinates int x1=INDENT_RIGHT; int y1=INDENT_TOP+CONTROLS_GAP_Y; int x2=x1+100; int y2=y1+20; //--- create if(!m_label.Create(m_chart_id,m_name+"Label",m_subwin,x1,y1,x2,y2)) return(false); if(!m_label.Text("Label123456")) return(false); if(!Add(m_label)) return(false); Comment(m_label.Text()); //--- succeed return(true); } //+------------------------------------------------------------------+ //| 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(); //--- return(INIT_SUCCEEDED); } //+------------------------------------------------------------------+ //| Expert deinitialization function | //+------------------------------------------------------------------+ void OnDeinit(const int reason) { //--- destroy dialog ExtDialog.Destroy(reason); } //+------------------------------------------------------------------+ //| Expert tick function | //+------------------------------------------------------------------+ void OnTick() { //--- MqlTick STick; if(SymbolInfoTick(Symbol(),STick)) { ExtDialog.ChangeText(DoubleToString(STick.ask,Digits())); } } //+------------------------------------------------------------------+ //| 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); } //+------------------------------------------------------------------+
Result:
Files:
Test_Panel.mq5
15 kb
Thanks again Vladimir. Little by little I am discovering how the classes work.
You are missing trading opportunities:
- Free trading apps
- Over 8,000 signals for copying
- Economic news for exploring financial markets
Registration
Log in
You agree to website policy and terms of use
If you do not have an account, please register
Thank you very much.