CODEWITHSUNDEEP
c++wxwidgets
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Reputation: 51

wxGauge was nullptr out of constructor

first of all sorry for my english, its not my first language

i'm beginner on wxWidgets for c++ and i started to developer a simple application with a progress bar and some background process

unfortunately when i call wx_MyGauge->SetValue(20), a exception "wx_MyGauge was nullptr" occurs

this only occurs outside the constructor, if i call that function from constructor, works perfectly

what am i doing wrong?

//header

#pragma once
#include "wx/wx.h"

class testGauge : public wxFrame
{
public:
    testGauge();
    ~testGauge();

    wxGauge* wx_MyGauge;
    wxPanel* pnl;

    void Importar(wxMouseEvent& event);
};

//cpp

#include "testGauge.h"
testGauge::testGauge() : wxFrame(nullptr, wxID_ANY, "blabla", wxDefaultPosition, wxSize(500, 400))
{
    pnl = new wxPanel(this, wxID_ANY, wxPoint(10, 10), wxSize(500, 400));

    wx_MyGauge= new wxGauge(pnl, 1001, 100, wxPoint(10,10), wxSize(100,20), wxGA_HORIZONTAL);
    wx_MyGauge->SetValue(10);// here OK

    wxButton* btn = new wxButton(pnl,wxID_ANY,"Teste",wxPoint(10,30),wxSize(50,30));
    btn->Connect(wxEVT_LEFT_UP, wxMouseEventHandler(testGauge::Importar));
    

    this->Layout();
    this->Centre(wxBOTH);
}


void testGauge::Importar(wxMouseEvent& WXUNUSED(event))
{
    testGauge::wx_MyGauge->SetValue(20);// here Error 
}

testGauge::~testGauge()
{

}

working on windows 10, visual studio 2019, wxWidgets 3.1.5

imageerror

Upvotes: 0

Views: 111

Answers (1)

3CxEZiVlQ
3CxEZiVlQ

Reputation: 38931

You call the method Connect of the pnl and don't pass which event handler Importar is. Thus, the method Connect joins the mouse event to pnl instead of testGuage

btn->Connect(wxEVT_LEFT_UP, wxMouseEventHandler(testGauge::Importar));

Must be

btn->Connect(wxEVT_LEFT_UP, wxMouseEventHandler(testGauge::Importar), nullptr, this);

Upvotes: 4

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