call glcontrol1_paint many times spontaneous

OpenGL OpenGL: Basic Coding
1

I am using the OpenTK and c#. I have developed a graphics application that works fine but is slow. I need help to improve the performance of the application. My application generates a model that is made up of several elements. This is what I do for each element :

1- test if element has a result.
2- open file and read the result of each element.
3- choice the color of the element switch of the value of the result.
4- draw the element.

I’m new in opentk, when i follow the execution of my program, i note that my program return to glcontrol1_paint many times ( and in my program i call once time).
i think that 's why my program is slow.

my function glControl1_Paint,

private void glControl1_Paint(object sender, PaintEventArgs e)
{
glControl1.MakeCurrent();
GL.End();
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);

            GL.PushMatrix();
            GL.Translate(x, 0, 0);
            GL.Translate(0, y, 0);
            GL.Translate(0, 0, z);
            GL.Translate(xp, yp, zp);
            GL.Rotate(rotationZ, Vector3.UnitZ);
            GL.Rotate(rotationY, Vector3.UnitY);
            GL.Rotate(rotationX, Vector3.UnitX);
            GL.Translate(-xp, -yp, -zp);
            GL.Scale(scale, scale, scale);
            
            Draw();

            GL.PopMatrix();
            glControl1.SwapBuffers();
                      
    }

Thanks.