/// <summary>
 /// Sets the picture box's visibility in a thread-safe way.
 /// </summary>
 /// <param name="visible">Whether the picture box is visible</param>
 public void setPictureBoxVisibility(bool visible)
 {
     if (pictureBox.InvokeRequired) //wrong thread
     {
         pictureBoxVisibilityCallback d = new pictureBoxVisibilityCallback(setPictureBoxVisibility);
         pictureBox.Invoke(d, new object[] { visible });
     }
     else //right thread
     {
         pictureBox.Visible = visible;
     }
 }
 /// <summary>
 /// Sets the picture box's visibility in a thread-safe way.
 /// </summary>
 /// <param name="visible">Whether the picture box is visible</param>
 public void setPictureBoxVisibility(bool visible)
 {
     if (pictureBox.InvokeRequired) //wrong thread
     {
         pictureBoxVisibilityCallback d = new pictureBoxVisibilityCallback(setPictureBoxVisibility);
         pictureBox.Invoke(d, new object[] { visible });
     }
     else //right thread
     {
         pictureBox.Visible = visible;
     }
 }