qt5.6.2 opengl GL_INVALID_OPERATION

[illidanee]

rencently, i used to render a model. but a problem come with me. when i init vao and vbo of my model in the Init() function, it can render nomal. but when drag and drop a model and in which callback function init vao and vbo of my model ,a error GL_INVALID_OPERATION come out. i try to do in many ways, but no method solves.how i can do？ the code is below.

#include "XLogin.h"
#include "XMainWindow.h"
#include "./OpenGL/XOpenGLWindow.h"
#include <QtWidgets/QApplication>

#include <QFile>

int main(int argc, char *argv[])
{
	QApplication::setAttribute(Qt::AA_UseDesktopOpenGL);
	QApplication::setAttribute(Qt::AA_UseSoftwareOpenGL);
	QApplication a(argc, argv);

	//当前目录
	QDir dir;
	qDebug() << "------ Start : Current Program Dir is = " << dir.currentPath() << endl;

	//设置风格 - 读取文件编码为UTF-8,否则需要转码。
	QFile styleSheet("app.css");
	styleSheet.open(QIODevice::ReadOnly);
	QString typle = styleSheet.readAll();
	a.setStyleSheet(typle);

	//设置OpenGL的版本信息
	QSurfaceFormat format;
	format.setSwapBehavior(QSurfaceFormat::DoubleBuffer);
	format.setRenderableType(QSurfaceFormat::OpenGL);
	format.setProfile(QSurfaceFormat::CoreProfile);
	format.setVersion(3, 3);
	format.setRedBufferSize(8);
	format.setGreenBufferSize(8);
	format.setBlueBufferSize(8);
	format.setAlphaBufferSize(8);
	format.setDepthBufferSize(24);
	format.setStencilBufferSize(8);
	format.setSamples(8);
	QSurfaceFormat::setDefaultFormat(format);

	//打开窗口
	XOpenGLWindow xOpenGLWindow;
	xOpenGLWindow.setFormat(format);
	xOpenGLWindow.setFixedSize(1280, 800);
	xOpenGLWindow.show();

	return a.exec();

}

#include "XOpenGLWindow.h"


XOpenGLWindow::XOpenGLWindow(QWidget *parent)
	:QOpenGLWidget(parent)
{
	//全屏
	m_bFullScreen = true;
	m_Width = 0;
	m_Height = 0;

	m_TimerID = 0;

	m_LastMouseX = 0;
	m_LastMouseY = 0;
}

XOpenGLWindow::~XOpenGLWindow()
{
	killTimer(m_TimerID);
}

void XOpenGLWindow::initializeGL()
{
	setAcceptDrops(true);

	//Init
	XManager::GetRef().Init();

	//启动定时器
	m_TimerID = startTimer(30);
}

void XOpenGLWindow::resizeGL(int width, int height)
{
	m_Width = width;
	m_Height = height;

	//Resize
	XManager::GetRef().m_Render->Resize(m_Width, m_Height);
}

void XOpenGLWindow::paintGL()
{
//Logic
	//更新
	XManager::GetRef().m_Camera->OnUpdate();
	

//Render
	XManager::GetRef().m_Render->Render(XManager::GetRef(), m_Width, m_Height);
	//XManager::GetRef().m_Skybox->Render(XManager::GetRef(), m_Width, m_Height);
}

void XOpenGLWindow::mousePressEvent(QMouseEvent *event)
{
	if (event->button() == Qt::RightButton)
	{
		XManager::GetRef().m_Camera->OnRightButtonDown(event->x(), event->y());
		ShowCursor(FALSE);
		m_LastMouseX = event->x();
		m_LastMouseY = event->y();
	}
}

void XOpenGLWindow::mouseReleaseEvent(QMouseEvent *event)
{
	if (event->button() == Qt::RightButton)
	{
		XManager::GetRef().m_Camera->OnRightButtonUp(event->x(), event->y());
		ShowCursor(TRUE);
		QPoint rect = this->pos();
		SetCursorPos(rect.x() + m_LastMouseX, rect.y() + m_LastMouseY);
	}
}

void XOpenGLWindow::mouseDoubleClickEvent(QMouseEvent *event)
{
	Q_UNUSED(event);
}

void XOpenGLWindow::mouseMoveEvent(QMouseEvent *event)
{
	XManager::GetRef().m_Camera->OnMouseMove(event->x(), event->y());
}

#ifndef QT_NO_WHEELEVENT
void XOpenGLWindow::wheelEvent(QWheelEvent *event)
{
	if (event->delta() > 0)
	{
		XManager::GetRef().m_Camera->OnZoomIn();
	}
	else
	{
		XManager::GetRef().m_Camera->OnZoomOut();
	}
}

#endif

void XOpenGLWindow::keyPressEvent(QKeyEvent *event)
{
	switch (event->key())
	{
	case Qt::Key_W:
	case Qt::Key_S:
	case Qt::Key_A:
	case Qt::Key_D:
		XManager::GetRef().m_Camera->OnKeyDown(event->key());
		break;
	case Qt::Key_1:
		if (event->modifiers() == Qt::AltModifier)
			close();
		break;
	default:
		QWidget::keyPressEvent(event);
		break;
	}
}

void XOpenGLWindow::keyReleaseEvent(QKeyEvent *event)
{
	switch (event->key())
	{
	case Qt::Key_W:
	case Qt::Key_S:
	case Qt::Key_A:
	case Qt::Key_D:
		XManager::GetRef().m_Camera->OnKeyUp(event->key());
		break;
	default:
		QWidget::keyPressEvent(event);
		break;
	}
}

void XOpenGLWindow::dragEnterEvent(QDragEnterEvent *event)
{
	if (event->mimeData()->hasFormat("text/uri-list"));
	{
		event->acceptProposedAction();
	}

}

void XOpenGLWindow::dropEvent(QDropEvent *event)
{
	QList<QUrl> urls = event->mimeData()->urls();
	if (urls.isEmpty())
		return;

	QString fileName = urls.first().toLocalFile();

	if (fileName.isEmpty())
		return;

	qDebug() << fileName;
	XManager::GetRef().m_Render->ResetFile("./Resources/Model/skin_man.FBX");
}

void XOpenGLWindow::timerEvent(QTimerEvent * event)
{
	repaint();
}

#include "Render.h"

#include <QMatrix4x4>
#include "../Manager.h"


XRender::XRender()
{

}

XRender::~XRender()
{

}

void XRender::Init()
{
	//Init OpenGL Functions
	initializeOpenGLFunctions();

	//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

	//Init value
	glClearColor(0.2f, 0.3f, 0.5f, 1.0f);
	glEnable(GL_DEPTH_TEST);
	glClearDepth(1.0f);

	fbx = new XFbxLoader();
	fbx->Init();
	fbx->LoadFbxFile("./Resources/Model/skin_man.fbx");	
	fbx->Reset();
	fbx->LoadFbxFile("./Resources/Model/skin_man.fbx");
}

void XRender::ResetFile(const char* pFileName)
{
	fbx->Reset();
	fbx->LoadFbxFile("./Resources/Model/tauren.fbx");
}

void XRender::Resize(int width, int height)
{
	glViewport(0, 0, width, height);
}

void XRender::Render(XManager& xManager, int width, int height)
{
	glViewport(0, 0, width, height);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	if (fbx)
		fbx->Render(width, height);
}