error C2440: 'static_cast' : cannot convert from 'void (__thiscall Visualizza::* )(ch-CodePudding

Can someone help me? I'm doing an MFC application via VS 2010 ultimate. ps. im new withth c . This application is for print on a combox filenames.

this is the .cpp file


BEGIN_MESSAGE_MAP(Visualizza, CDialogEx)
    ON_CBN_SELCHANGE(IDC_COMBO1, &Visualizza::OnCbnSelchangeCombo1)
END_MESSAGE_MAP()


// Visualizza message handlers


void Visualizza::OnCbnSelchangeCombo1(char util[20])
{
    std::string s = util;
    LPTSTR x = new TCHAR[s.size()   1];
    stampa.AddString(x);
}

and this is the .h file

#pragma once
#include "afxwin.h"


// Visualizza dialog

class Visualizza : public CDialogEx
{
    DECLARE_DYNAMIC(Visualizza)

public:
    Visualizza(CWnd* pParent = NULL);   // standard constructor
    virtual ~Visualizza();

// Dialog Data
    enum { IDD = IDD_DIALOG1 };

protected:
    virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support

    DECLARE_MESSAGE_MAP()
public:
    afx_msg void OnCbnSelchangeCombo1(char util[20]);
    CComboBox stampa;
};

CodePudding user response：

Registering notification handlers is explained in the Remarks section of the CComboBox documentation. In particular, the following needs to be followed:

The parent's function prototype is as follows:
afx_msg void memberFxn( );

In other words: Your user-supplied notification handlers cannot take any arguments.

void Visualizza::OnCbnSelchangeCombo1(char util[20])

would need to be changed to

void Visualizza::OnCbnSelchangeCombo1()

to make it compatible with the ON_CBN_SELCHANGE(IDC_COMBO1, &Visualizza::OnCbnSelchangeCombo1) message map entry.