how to use opengl native function in my function ,not in initializeGL(),paintGL(),resizeGL(int w, int h)

[Mr Lonely]

I write a program to read 3D obj file and show it in QopenglWidget. When I read the file in initializeGL() and set the VAO in it,everything is ok.Also I try to change the path, the result is fine.But when I do these things in my function mySlotOpenFile() ,I get wrong result,why?
frist picture is the sphere1.obj contain a plane and a sphere
![5804d1e6-9df7-4f57-8937-a30470fdc980-N$Z$4KP8]WPWF4V8]FUQ}CR.png](https://ddgobkiprc33d.cloudfront.net/216346b9-fc56-4038-81fb-ae83f720091e.png)
second picture is sphere.obj contain a small sphere

And in third pciure ,I open sphere1.obj in nitializeGL() ,and then open sphere.obj in my function mySlotOpenFile() .which I get is this ,why?

#include "glWidget.h"
#include <QMessageBox>
#include<Qmath.h>
#include<Qdebug>
#include<FileSystem>
glWidget::glWidget(QWidget *parent)
	: QOpenGLWidget(parent)
{
	myrender = NULL;
}

glWidget::~glWidget()
{
}

void glWidget::initializeGL()
{
	core = QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_4_3_Core>();
	myrender = new MyRender(core);
	//myrender->openFile("easymodel/sphere.obj");
	drawFlag = true;
}

void glWidget::paintGL()
{
	if (drawFlag==false)
	{
		return;
	}
	myrender->Draw();
	update();
}

void glWidget::resizeGL(int w, int h)
{
	
}


void glWidget::mySlot2(int front, int back,int left,int right)
{
	myrender->setCameraPos(front, back, left, right);
}

void glWidget::mySlotMosue(QPointF firstPoint, QPointF nextPoint)
{
	myrender->setCameraFront(firstPoint, nextPoint);
}

void glWidget::mySlotOpenFile()
{
	this->makeCurrent();
	//auto *ctx = QOpenGLContext::currentContext();
	drawFlag = false;
	//myrender = new MyRender(core);
	QString fileName = QFileDialog::getOpenFileName(NULL, "标题", ".");
	if (fileName!="")
	{
		myrender->openFile(fileName);
	}
	core->glClearColor(0.6f, 0.2f, 0.2f, 1.0f);

	drawFlag = true;
	this->doneCurrent();
	update();
}

[SGaist]

Hi and welcome to devnet,

I would start with using QOpenGLWidget::context to use the one associated with your widget.

Are you sure your MyRender class does not do anything unusual with regard to the OpenGL state ?