Прокрутка PictureBox в .NET?

Question

У меня есть фотобумага, которая занимает 512х512. Это путь к большому, я могу сделать его 256x1024, что предпочтительнее, но тогда как сделать его прокручиваемым?

Answer 1

class ScrollablePictureBox : PictureBox 
{ 
    public PictureBox pic = new PictureBox(); 
    public PictureBox picCorner = new PictureBox(); 
    HScrollBar hScroll = new HScrollBar(); 
    VScrollBar vScroll = new VScrollBar(); 
    int w, h, scrollAmount; 
    public ScrollablePictureBox(int w_, int h_, Image img, int scrollAmount) 
    { 
     AddControls(); 
     Set(w_, h_, img, scrollAmount); 
    } 
    public ScrollablePictureBox() 
    { 
     AddControls(); 
    } 
    public void ScrollEvent(object sender, MouseEventArgs e) 
    { 
     if (e.Delta == 0) 
      return; 

     var v = vScroll.Value + (e.Delta >= 120 ? -scrollAmount : scrollAmount); 
     v = v > vScroll.Maximum ? vScroll.Maximum : v; 
     v = v < vScroll.Minimum ? vScroll.Minimum : v; 
     vScroll.Value = v; 
    } 
    void AddControls() 
    { 
     picCorner.BackColor = Color.Gray; 
     vScroll.ValueChanged += Vert_EventHandler; 

     this.Controls.Add(picCorner); 
     this.Controls.Add(vScroll); 
     this.Controls.Add(hScroll); 
     this.Controls.Add(pic);    
    } 
    public void Set(int w_, int h_, Image img, int scrollAmount_) 
    { 
     w = w_; 
     h = h_; 
     scrollAmount = scrollAmount_; 
     pic.Image = img; 
     pic.Width = img.Width; 
     pic.Height = img.Height; 

     if (w >= img.Width) 
     { 
      this.Width = w; 
      hScroll.Visible = false; 
     } 
     else 
     { 
      hScroll.Left = 0; 
      hScroll.Top = h; 
      hScroll.Width = w; 
      hScroll.Minimum = 0; 
      hScroll.Maximum = pic.Image.Width - w; 
      hScroll.Scroll += hScrollBar1_Scroll; 
      hScroll.Visible = true; 
     } 

     if (h >= img.Height) 
     { 
      this.Width = w; 
      vScroll.Visible = false; 
     } 
     else 
     { 
      vScroll.Left = w; 
      vScroll.Top = 0; 
      vScroll.Height = h; 
      vScroll.Minimum = 0; 
      vScroll.Maximum = pic.Image.Height - h; 
      vScroll.Scroll += vScrollBar1_Scroll; 
      vScroll.Visible = true; 
     } 

     this.Width = vScroll.Visible ? w + vScroll.Width : w; 
     this.Height = hScroll.Visible ? h + hScroll.Height: h; 

     picCorner.Left = vScroll.Left; 
     picCorner.Width = vScroll.Width; 
     picCorner.Top = hScroll.Top; 
     picCorner.Height = hScroll.Height; 
     picCorner.BackColor = this.BackColor; 
     picCorner.Visible = (vScroll.Visible && hScroll.Visible); 
    } 
    void hScrollBar1_Scroll(object sender, ScrollEventArgs e) 
    { 
     pic.Left = -e.NewValue; 
    } 
    void vScrollBar1_Scroll(object sender, ScrollEventArgs e) 
    { 
     pic.Top = -e.NewValue; 
    } 
    void Vert_EventHandler(object sender, EventArgs e) 
    { 
     pic.Top = -vScroll.Value; 
    } 
}