protected override void OnMouseUp(MouseEventArgs e)
 {
     base.OnMouseUp(e);
     //
     if (this.m_SplitLineForm != null)
     {
         this.m_SplitLineForm.Close();
         this.m_SplitLineForm = null;
     }
     if (!this.m_bIsMouseDown)
     {
         return;
     }
     this.m_bIsMouseDown = false;
     //
     this.SetSplitPanelSize(e.Location);
 }
 protected override void OnMouseDown(MouseEventArgs e)
 {
     base.OnMouseDown(e);
     //
     if (this.DisplayRectangle.Contains(e.Location))
     {
         return;
     }
     //
     if (this.m_SplitLineForm != null)
     {
         this.m_SplitLineForm.Close();
         this.m_SplitLineForm = null;
     }
     this.m_bIsMouseDown  = true;
     this.m_SplitLineForm = new SplitLineForm();//key
     this.m_SplitLineForm.Show(this.SplitPanelDock, this.SplitterScreenRectangle);
     //
     this.SetOutSize();
 }