Visual Studio 2003 .NET Panel con Scroll solo vertical o horizontal

Si estás trabajando con Visual Studio 2003 .NET es decir con el framework 1.1 puedes que tenga la siguiente problemática dentro de los controles de tipo “Panel”, ya que dicho panel tienes la opción de “AutoScroll” que esta opción habilitaría el scroll dentro de vuestro panel pero claro podría darse el caso que solo queremos que el scroll aparezca en horizontal o el vertical solamente. Esto por defecto no está implementado en el framework 1.1 de Microsoft pero buscando por internet encontrado una solución para poder realizar esta tarea.

Vamos a trabaja con el siguiente ejemplo:

Resultado:

Como vemos tenemos la propiedad de “AutoScroll” activado y aparece los dos scroll tanto el vertical como el horizontal. Este ejemplo vamos es modificar nuestra aplicación para solo mostrar el Scroll vertical.

Paso 1: Añadir nueva clase a nuestro proyecto.

Esta clase se base el componente “System.Windows.Forms.Panel” pero añadiendo nuevas funcionalidades y propiedades.

ScrollablePanel.cs

 
using System;

namespace CustomAutoScrollPanel
{
 using System;
 using System.Windows.Forms;
 using System.Runtime.InteropServices ;

 /// 

 /// Description résumée de ScrollablePanel.
 /// 
 public class ScrollablePanel: System.Windows.Forms.Panel
 {

  #region Delegates & events

  public event System.Windows.Forms.ScrollEventHandler ScrollHorizontal;
  public event System.Windows.Forms.ScrollEventHandler ScrollVertical;
  public event System.Windows.Forms.MouseEventHandler  ScrollMouseWheel;

  #endregion

  #region Const

  private const int SB_LINEUP = 0;
  private const int SB_LINEDOWN = 1; 
  private const int SB_PAGEUP = 2; 
  private const int SB_PAGEDOWN = 3;
  private const int SB_THUMBPOSITION = 4; 
  private const int SB_THUMBTRACK = 5; 
  private const int SB_TOP = 6; 
  private const int SB_BOTTOM = 7; 
  private const int SB_ENDSCROLL = 8; 

  private const int WM_HSCROLL = 0x114;
  private const int WM_VSCROLL = 0x115;
  private const int WM_MOUSEWHEEL = 0x020A;
  private const int WM_NCCALCSIZE =0x0083;
  private const int WM_PAINT =0x000F;
  private const int WM_SIZE =0x0005;

  private const uint SB_HORZ = 0; 
  private const uint SB_VERT = 1; 
  private const uint SB_CTL = 2; 
  private const uint SB_BOTH = 3; 

  private const uint  ESB_DISABLE_BOTH = 0x3;
  private const uint  ESB_ENABLE_BOTH = 0x0;

  private const int  MK_LBUTTON = 0x01;
  private const int  MK_RBUTTON = 0x02;
  private const int  MK_SHIFT = 0x04;
  private const int  MK_CONTROL = 0x08;
  private const int  MK_MBUTTON = 0x10; 
  private const int  MK_XBUTTON1 = 0x0020;
  private const int  MK_XBUTTON2 = 0x0040;

  #endregion

  #region Vars
  
  private bool enableAutoHorizontal = true;
  private bool enableAutoVertical = true;
  private bool visibleAutoHorizontal = true;
  private bool visibleAutoVertical = true;

  private int autoScrollHorizontalMinimum = 0;
  private int autoScrollHorizontalMaximum = 100;

  private int autoScrollVerticalMinimum = 0;
  private int autoScrollVerticalMaximum = 100;

  #endregion

  #region Constructor

  public ScrollablePanel()
  {
   this.Click += new EventHandler(ScrollablePanel_Click);
   this.AutoScroll = true;
  }

  #endregion

  #region Properties

  public int AutoScrollHPos
  {
   get { return GetScrollPos(this.Handle, (int)SB_HORZ); }
   set { SetScrollPos(this.Handle, (int)SB_HORZ, value, true); }
  }

  public int AutoScrollVPos
  {
   get { return GetScrollPos(this.Handle, (int)SB_VERT); }
   set { SetScrollPos(this.Handle, (int)SB_VERT, value, true); }
  }

  public int AutoScrollHorizontalMinimum
  {
   get { return this.autoScrollHorizontalMinimum;  }
   set { 
    this.autoScrollHorizontalMinimum = value; 
    SetScrollRange(this.Handle, (int)SB_HORZ, autoScrollHorizontalMinimum, autoScrollHorizontalMaximum, true);   
   }
  }

  public int AutoScrollHorizontalMaximum
  {
   get { return this.autoScrollHorizontalMaximum;  }
   set { 
    this.autoScrollHorizontalMaximum = value; 
    SetScrollRange(this.Handle, (int)SB_HORZ, autoScrollHorizontalMinimum, autoScrollHorizontalMaximum, true);
   }
  }

  public int AutoScrollVerticalMinimum
  {
   get { return this.autoScrollVerticalMinimum;  }
   set { 
    this.autoScrollVerticalMinimum = value; 
    SetScrollRange(this.Handle, (int)SB_VERT, autoScrollHorizontalMinimum, autoScrollHorizontalMaximum, true);
   }
  }

  public int AutoScrollVerticalMaximum
  {
   get { return this.autoScrollVerticalMaximum;  }
   set { 
    this.autoScrollVerticalMaximum = value; 
    SetScrollRange(this.Handle, (int)SB_VERT, autoScrollHorizontalMinimum, autoScrollHorizontalMaximum, true);
   }
  }


  public bool EnableAutoScrollHorizontal
  {
   get { return this.enableAutoHorizontal;  }
   set { 
    this.enableAutoHorizontal = value;
    if (value)
     EnableScrollBar(this.Handle, SB_HORZ, ESB_ENABLE_BOTH);
    else
     EnableScrollBar(this.Handle, SB_HORZ, ESB_DISABLE_BOTH);
   }
  }

  public bool EnableAutoScrollVertical
  {
   get { return this.enableAutoVertical;  }
   set { 
    this.enableAutoVertical = value; 
    if (value)
     EnableScrollBar(this.Handle, SB_VERT, ESB_ENABLE_BOTH);
    else
     EnableScrollBar(this.Handle, SB_VERT, ESB_DISABLE_BOTH);
   }
  }

  public bool VisibleAutoScrollHorizontal
  {
   get { return this.visibleAutoHorizontal; }
   set
   {
    this.visibleAutoHorizontal = value;
    ShowScrollBar(this.Handle, (int)SB_HORZ, value);
   }
  }

  public bool VisibleAutoScrollVertical
  {
   get { return this.visibleAutoVertical; }
   set
   {
    this.visibleAutoVertical = value;
    ShowScrollBar(this.Handle, (int)SB_VERT, value);
   }
  }

  #endregion

  #region ScrollEventType to SB_* messages and SB_* messages to ScrollEventType
  
  private int getSBFromScrollEventType(ScrollEventType type)
  {
   int res = -1;
   switch (type)
   {
    case ScrollEventType.SmallDecrement:
     res = SB_LINEUP;
     break;
    case ScrollEventType.SmallIncrement:
     res = SB_LINEDOWN;
     break;
    case ScrollEventType.LargeDecrement:
     res = SB_PAGEUP;
     break;
    case ScrollEventType.LargeIncrement:
     res = SB_PAGEDOWN;
     break;
    case ScrollEventType.ThumbTrack:
     res = SB_THUMBTRACK;
     break;
    case ScrollEventType.First:
     res = SB_TOP;
     break;
    case ScrollEventType.Last:
     res = SB_BOTTOM;
     break;
    case ScrollEventType.ThumbPosition:
     res = SB_THUMBPOSITION;
     break;
    case ScrollEventType.EndScroll:
     res = SB_ENDSCROLL;
     break;
    default:
     break;
   }
   return res;
  }

  private ScrollEventType getScrollEventType(System.IntPtr wParam)
  {
   ScrollEventType res = 0;
   switch (LoWord((int)wParam)) 
   {
    case SB_LINEUP:
     res = ScrollEventType.SmallDecrement;
     break;
    case SB_LINEDOWN:
     res = ScrollEventType.SmallIncrement;
     break;
    case SB_PAGEUP:
     res = ScrollEventType.LargeDecrement;
     break;
    case SB_PAGEDOWN:
     res = ScrollEventType.LargeIncrement;
     break;
    case SB_THUMBTRACK:
     res = ScrollEventType.ThumbTrack;
     break;
    case SB_TOP:
     res = ScrollEventType.First;
     break;
    case SB_BOTTOM:
     res = ScrollEventType.Last;
     break;
    case SB_THUMBPOSITION:
     res = ScrollEventType.ThumbPosition;
     break;
    case SB_ENDSCROLL:
     res = ScrollEventType.EndScroll;
     break;
    default:
     res = ScrollEventType.EndScroll;
     break;
   }
   return res;
  }

  #endregion

  #region WndProd override

  protected override void WndProc(ref Message msg)
  {
   base.WndProc(ref msg);
   if (msg.HWnd != this.Handle)
    return;
   switch (msg.Msg)
   {
    case WM_MOUSEWHEEL:
     if (!this.VisibleAutoScrollVertical)
      return;
     try
     {
      int zDelta = HiWord((int)msg.WParam);
      int y = HiWord((int)msg.LParam);
      int x = LoWord((int)msg.LParam);
      System.Windows.Forms.MouseButtons butt;
      switch (LoWord((int)msg.WParam))
      {
       case MK_LBUTTON:
        butt = System.Windows.Forms.MouseButtons.Left;
        break;
       case MK_MBUTTON:
        butt = System.Windows.Forms.MouseButtons.Middle;
        break;
       case MK_RBUTTON:
        butt = System.Windows.Forms.MouseButtons.Right;
        break;
       case MK_XBUTTON1:
        butt = System.Windows.Forms.MouseButtons.XButton1;
        break;
       case MK_XBUTTON2:
        butt = System.Windows.Forms.MouseButtons.XButton2;
        break;
       default:
        butt = System.Windows.Forms.MouseButtons.None;
        break;
      }
      System.Windows.Forms.MouseEventArgs arg0 = new System.Windows.Forms.MouseEventArgs(butt, 1, x, y, zDelta);
      this.ScrollMouseWheel(this, arg0);
     }
     catch (Exception) { }
     
     break;

    case WM_VSCROLL:
     
     try
     {
      ScrollEventType type = getScrollEventType(msg.WParam);
      ScrollEventArgs arg = new ScrollEventArgs(type, GetScrollPos(this.Handle, (int)SB_VERT));
      this.ScrollVertical(this, arg);
     }
     catch (Exception) { }
     
     break;

    case WM_HSCROLL:

     try
     {
      ScrollEventType type = getScrollEventType(msg.WParam);
      ScrollEventArgs arg = new ScrollEventArgs(type, GetScrollPos(this.Handle, (int)SB_HORZ));
      this.ScrollHorizontal(this, arg);
     }
     catch (Exception) { }
     
     break;

    default:
     break;
   }
  }

  #endregion

  #region Perform Manuel scrolling

  public void performScrollHorizontal(ScrollEventType type)
  {
   int param = getSBFromScrollEventType(type);
   if (param == -1)
    return;
   SendMessage(this.Handle, (uint)WM_HSCROLL, (System.UIntPtr)param, (System.IntPtr)0);
  }

  public void performScrollVertical(ScrollEventType type)
  {
   int param = getSBFromScrollEventType(type);
   if (param == -1)
    return;
   SendMessage(this.Handle, (uint)WM_VSCROLL, (System.UIntPtr)param, (System.IntPtr)0); 
  }

  #endregion

  #region Panel Got focus

  private void ScrollablePanel_Click(object sender, EventArgs e)
  {
   this.Focus();
  }

  #endregion
  
  #region API32 functions

  [DllImport("user32.dll", CharSet=CharSet.Auto)]
  static public extern int GetSystemMetrics(int code);

  [DllImport("user32.dll")]
  static public extern bool EnableScrollBar(System.IntPtr hWnd, uint wSBflags, uint wArrows);

  //[DllImport("user32.dll")]
  //static public extern bool GetScrollInfo(System.IntPtr hwnd, int fnBar, LPSCROLLINFO lpsi);

  [DllImport("user32.dll")]
  static public extern int SetScrollRange(System.IntPtr hWnd, int nBar, int nMinPos, int nMaxPos, bool bRedraw);

  [DllImport("user32.dll")]
  static public extern int SetScrollPos(System.IntPtr hWnd, int nBar, int nPos, bool bRedraw);
  
  [DllImport("user32.dll")]
  static public extern int GetScrollPos(System.IntPtr hWnd, int nBar);
  
  /*
  public struct LPSCROLLINFO 
  { 
   uint cbSize; 
   uint fMask; 
   int  nMin; 
   int  nMax; 
   uint nPage; 
   int  nPos; 
   int  nTrackPos; 
  }
  */

  [DllImport("user32.dll")]
  static public extern bool ShowScrollBar(System.IntPtr hWnd, int wBar, bool bShow);
  
  [DllImport("user32.dll")]
  static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, UIntPtr wParam, IntPtr lParam);

  [DllImport("user32.dll")]
  static extern int HIWORD(System.IntPtr wParam);

  static int MakeLong(int LoWord, int HiWord) 
  { 
   return (HiWord << 16) | (LoWord & 0xffff); 
  } 
 
  static IntPtr MakeLParam(int LoWord, int HiWord) 
  { 
   return (IntPtr) ((HiWord << 16) | (LoWord & 0xffff)); 
  }
               
  static int HiWord(int number) 
  {
   if ((number & 0x80000000) == 0x80000000)
    return (number >> 16); 
   else
    return (number >> 16) & 0xffff ; 
  } 
  
  static int LoWord(int number) 
  { 
   return number & 0xffff; 
  }

  #endregion

 }
}
 

Paso 2: Modificar nuestro panel.

• Modificamos el tipo de nuestro panel por el nuevo tipo

// Cambio su tipo
//private System.Windows.Forms.Panel panel1;
private CustomAutoScrollPanel.ScrollablePanel panel1;

• Modificamos al InitializeComponent que donde se inicializa el objeto, ya que ahora es de otro tipo.

private void InitializeComponent()
{
       this.panel1 = new CustomAutoScrollPanel.ScrollablePanel();

• Modificar el constructor de nuestro formulario.

public Form1()
{
 //
 // Necesario para admitir el Diseñador de Windows Forms
 //
 InitializeComponent();

 //
 // TODO: agregar código de constructor después de llamar a InitializeComponent
 //
 this.panel1.AutoScroll = true;
 this.panel1.EnableAutoScrollHorizontal = false;
 this.panel1.VisibleAutoScrollHorizontal = false;
 this.panel1.EnableAutoScrollVertical = true;
 this.panel1.VisibleAutoScrollVertical = true;
}

Ahora ya desde nuestro editor ya podremos configurar que Scroll queremos mostrar el horizontal o el vertical.

Fuente: URL