c++ - QWidget::repaint:使用指针检测到递归重绘

Question

我收到以下错误:

QWidget::repaint: Recursive repaint detected.

QPainter::begin: A paint device can only be painted by one painter at a` time.
QPainter::beginNativePainting: Painter not active.
QPainter::setRenderHint: Painter must be active to set rendering hints.
QPainter::translate: Painter not active.

void Graficador::paintEvent(QPaintEvent *event){

QPainter painter;

painter.begin(this);
painter.beginNativePainting();
painter.setRenderHint(QPainter::Antialiasing);
painter.translate(250, 250);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-1.0,1.0,-1.0,1.0,-1.0,1.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glClearColor(0.2,0.4,0.3,1);
    glClear(GL_COLOR_BUFFER_BIT);

std::vector<unsigned short> nodosaux;
glPushMatrix();
for (unsigned i=1;i<=automata->Dimension();i++)
 {
   nodosaux=(automata->operator [](i))->Nodos();

   if((automata->operator [](i))->Estado()==0)

       glColor3f(0.3,0.3,0.3);  

               else if((automata->operator [](i))->Estado()==1.0)

                       glColor3f(1.0,1.0,1.0);

                   else if((automata->operator [](i))->Estado()==2.0)

                           glColor3f(0.7,0.7,0.7);

        glBegin(GL_POLYGON);

            for(unsigned j=1;j<=nodosaux.size();j++)
                {
                     glVertex2f(automata->Nodo(nodosaux[j-1]).first,
                                automata->Nodo(nodosaux[j-1]).second);

                }

        glEnd();

        glColor3f(0.0,0.0,0.0);

        glBegin(GL_LINE_LOOP);

        for(unsigned j=1;j<=nodosaux.size();j++)
            {
                 glVertex2f(automata->Nodo(nodosaux[j-1]).first,
                            automata->Nodo(nodosaux[j-1]).second);

            }

        glEnd();
         }


 glPopMatrix();

   glPushMatrix();

   glColor3f(1.0f,1.0f,1.0f);
   glBegin(GL_LINES);

       glVertex2f(-500.0,0.0);
       glVertex2f(500.0,0.0);
       glVertex2f(0.0,-500.0);
       glVertex2f(0.0,500.0);



  glEnd();

   glPopMatrix();

   painter.endNativePainting();

   painter.end();


}

(抱歉使用操作符，我知道它不正确使用但我需要先解决这个问题)。

这是 QGLWidget 的 paintEvent()。在我开始使用我的类“automata”的指针之前，我没有遇到任何问题。这个类只有一些顶点坐标为 (x,y) 的 vector ，所以我不知道为什么会出现这个问题。

完整的程序有一个大类系统，里面有:一个用户界面，一个自动机和一些用于其他任务的其他类。用户界面里面有这个QGLWidget，我在这里尝试使用的自动机是一个指向系统类中自动机的指针。

我像这样传递指针:

void Cargar_automata(Automata_Celular* ac)
{
 automata = new Automata_Celular();
 automata =ac;
 }

我还有一些其他小部件，但它们只是管理文件和计时器的按钮。

Answer 1

在 Qt 中使用 OpenGL 小部件时，所有绘制都应在名为 paintGL() 的成员中完成。您正在使用 paintEvent，这是导致您看到的错误消息的原因。

所以你的代码应该是这样的:

void Graficador::paintGL(){

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-1.0,1.0,-1.0,1.0,-1.0,1.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glClearColor(0.2,0.4,0.3,1);
    glClear(GL_COLOR_BUFFER_BIT);

std::vector<unsigned short> nodosaux;
glPushMatrix();
for (unsigned i=1;i<=automata->Dimension();i++)
 {
   nodosaux=(automata->operator [](i))->Nodos();

   if((automata->operator [](i))->Estado()==0)

       glColor3f(0.3,0.3,0.3);  

               else if((automata->operator [](i))->Estado()==1.0)

                       glColor3f(1.0,1.0,1.0);

                   else if((automata->operator [](i))->Estado()==2.0)

                           glColor3f(0.7,0.7,0.7);

        glBegin(GL_POLYGON);

            for(unsigned j=1;j<=nodosaux.size();j++)
                {
                     glVertex2f(automata->Nodo(nodosaux[j-1]).first,
                                automata->Nodo(nodosaux[j-1]).second);

                }

        glEnd();

        glColor3f(0.0,0.0,0.0);

        glBegin(GL_LINE_LOOP);

        for(unsigned j=1;j<=nodosaux.size();j++)
            {
                 glVertex2f(automata->Nodo(nodosaux[j-1]).first,
                            automata->Nodo(nodosaux[j-1]).second);

            }

        glEnd();
         }


 glPopMatrix();

   glPushMatrix();

   glColor3f(1.0f,1.0f,1.0f);
   glBegin(GL_LINES);

       glVertex2f(-500.0,0.0);
       glVertex2f(500.0,0.0);
       glVertex2f(0.0,-500.0);
       glVertex2f(0.0,500.0);



  glEnd();

   glPopMatrix();
}