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AutoScrollSmallChange Property

Summary

Gets or sets the amount that the scroll bar is incremented or decremented for a small scroll.

Syntax

C++

[BrowsableAttribute(false)] 
public virtual Size AutoScrollSmallChange {get;}

<BrowsableAttribute(False)> 
Public Overridable ReadOnly Property AutoScrollSmallChange As Size

[BrowsableAttribute(false)] 
public: 
virtual property Size AutoScrollSmallChange { 
   Size get(); 
}

Property Value

The amount that the scroll bar is incremented or decremented.

Remarks

A small scroll (or a line scroll) occurs when the user clicks an arrow.

Example

This example hides the RasterImageViewer control scroll bars and creates two custom scrollbars.

Imports Leadtools.WinForms 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing.Color 
Imports Leadtools.Drawing 
 
Private Class MyForm3 : Inherits Form 
   Public viewer As RasterImageViewer 
   Private panel As Panel 
   Private myHScroll As HScrollBar 
   Private myVScroll As VScrollBar 
   Public Sub New(ByVal title As String) 
      Text = title 
 
      Me.Size = New Size(750, 450) 
 
      panel = New Panel() 
      panel.Dock = DockStyle.Fill 
      Controls.Add(panel) 
 
      ' Create the raster viewer 
      viewer = New RasterImageViewer() 
      viewer.Dock = DockStyle.Fill 
      viewer.Width = 500 
      viewer.DoubleBuffer = True 
      panel.Controls.Add(viewer) 
 
      ' Load an image into the viewer 
      Dim codecs As RasterCodecs = New RasterCodecs() 
      viewer.Image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Sample1.cmp")) 
      codecs.Dispose() 
 
      viewer.AutoScroll = False 
      Dim size As Size = viewer.AutoScrollMinSize 
 
      ' Create two scrollbar controls for scrolling 
 
      myHScroll = New HScrollBar() 
      myHScroll.Location = New Point(100, 50) 
      myHScroll.Dock = DockStyle.Top 
      myHScroll.Height *= 2 
      myHScroll.Minimum = 0 
      myHScroll.Maximum = viewer.Image.Width 
      AddHandler myHScroll.ValueChanged, AddressOf hScroll_ValueChanged 
      panel.Controls.Add(myHScroll) 
      myHScroll.BringToFront() 
 
      myVScroll = New VScrollBar() 
      myVScroll.Dock = DockStyle.Left 
      myVScroll.Location = New Point(100, 100) 
      myVScroll.Width *= 2 
      myVScroll.Minimum = 0 
      myVScroll.Maximum = viewer.Image.Height 
      AddHandler myVScroll.ValueChanged, AddressOf vScroll_ValueChanged 
      panel.Controls.Add(myVScroll) 
      myVScroll.BringToFront() 
 
      viewer.BringToFront() 
 
      OnSizeChanged(EventArgs.Empty) 
   End Sub 
 
   Private Sub vScroll_ValueChanged(ByVal sender As Object, ByVal e As EventArgs) 
      viewer.ScrollPosition = New Point(myHScroll.Value, myVScroll.Value) 
   End Sub 
 
   Private Sub hScroll_ValueChanged(ByVal sender As Object, ByVal e As EventArgs) 
      viewer.ScrollPosition = New Point(myHScroll.Value, myVScroll.Value) 
   End Sub 
 
   Protected Overrides Sub OnSizeChanged(ByVal e As EventArgs) 
      If (Not myHScroll Is Nothing) AndAlso (Not myVScroll Is Nothing) Then 
         myHScroll.SmallChange = viewer.AutoScrollSmallChange.Width 
         myHScroll.LargeChange = viewer.AutoScrollLargeChange.Width 
         myVScroll.SmallChange = viewer.AutoScrollSmallChange.Height 
         myVScroll.LargeChange = viewer.AutoScrollLargeChange.Height 
 
         Console.WriteLine("AutoScrollSmallChange  {0}", viewer.AutoScrollSmallChange) 
         Console.WriteLine("AutoScrollLargeChange  {0}", viewer.AutoScrollLargeChange) 
         Console.WriteLine("AutoScrollMinSize      {0}", viewer.AutoScrollMinSize) 
         Console.WriteLine("SmallScrollChangeRatio {0}", viewer.SmallScrollChangeRatio) 
         Console.WriteLine("HScroll                {0}", viewer.HScroll) 
         Console.WriteLine("VScroll                {0}", viewer.VScroll) 
         Console.WriteLine("") 
 
         myHScroll.Enabled = viewer.HScroll 
         myVScroll.Enabled = viewer.VScroll 
      End If 
      MyBase.OnSizeChanged(e) 
   End Sub 
 
End Class 
 
Public Sub RasterImageViewer_HScroll(ByVal title As String) 
   Dim form As MyForm3 = New MyForm3(title) 
   form.ShowDialog() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" 
End Class

using Leadtools.WinForms; 
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Drawing; 
 
class MyForm3 : Form 
{ 
   public RasterImageViewer viewer; 
   Panel panel; 
   HScrollBar hScroll; 
   VScrollBar vScroll; 
   public MyForm3(string title) 
   { 
      Text = title; 
 
      Size = new Size(750, 450); 
 
      panel = new Panel(); 
      panel.Dock = DockStyle.Fill; 
      Controls.Add(panel); 
 
      // Create the raster viewer 
      viewer = new RasterImageViewer(); 
      viewer.Dock = DockStyle.Fill; 
      viewer.Width = 500; 
      viewer.DoubleBuffer = true; 
      panel.Controls.Add(viewer); 
 
      // Load an image into the viewer 
      RasterCodecs codecs = new RasterCodecs(); 
      viewer.Image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Sample1.cmp")); 
      codecs.Dispose(); 
 
      viewer.AutoScroll = false; 
      Size size = viewer.AutoScrollMinSize; 
 
      // Create two scrollbar controls for scrolling 
 
      hScroll = new HScrollBar(); 
      hScroll.Location = new Point(100, 50); 
      hScroll.Dock = DockStyle.Top; 
      hScroll.Height *= 2; 
      hScroll.Minimum = 0; 
      hScroll.Maximum = viewer.Image.Width; 
      hScroll.ValueChanged += new EventHandler(hScroll_ValueChanged); 
      panel.Controls.Add(hScroll); 
      hScroll.BringToFront(); 
 
      vScroll = new VScrollBar(); 
      vScroll.Dock = DockStyle.Left; 
      vScroll.Location = new Point(100, 100); 
      vScroll.Width *= 2; 
      vScroll.Minimum = 0; 
      vScroll.Maximum = viewer.Image.Height; 
      vScroll.ValueChanged += new EventHandler(vScroll_ValueChanged); 
      panel.Controls.Add(vScroll); 
      vScroll.BringToFront(); 
 
      viewer.BringToFront(); 
 
      OnSizeChanged(EventArgs.Empty); 
   } 
 
   void vScroll_ValueChanged(object sender, EventArgs e) 
   { 
      viewer.ScrollPosition = new Point(hScroll.Value, vScroll.Value); 
   } 
 
   void hScroll_ValueChanged(object sender, EventArgs e) 
   { 
      viewer.ScrollPosition = new Point(hScroll.Value, vScroll.Value); 
   } 
 
   protected override void OnSizeChanged(EventArgs e) 
   { 
      if((hScroll != null) && (vScroll != null)) 
      { 
         hScroll.SmallChange = viewer.AutoScrollSmallChange.Width; 
         hScroll.LargeChange = viewer.AutoScrollLargeChange.Width; 
         vScroll.SmallChange = viewer.AutoScrollSmallChange.Height; 
         vScroll.LargeChange = viewer.AutoScrollLargeChange.Height; 
 
         Console.WriteLine("AutoScrollSmallChange  {0}", viewer.AutoScrollSmallChange); 
         Console.WriteLine("AutoScrollLargeChange  {0}", viewer.AutoScrollLargeChange); 
         Console.WriteLine("AutoScrollMinSize      {0}", viewer.AutoScrollMinSize); 
         Console.WriteLine("SmallScrollChangeRatio {0}", viewer.SmallScrollChangeRatio); 
         Console.WriteLine("HScroll                {0}", viewer.HScroll); 
         Console.WriteLine("VScroll                {0}", viewer.VScroll); 
         Console.WriteLine(""); 
 
         hScroll.Enabled = viewer.HScroll; 
         vScroll.Enabled = viewer.VScroll; 
      } 
      base.OnSizeChanged(e); 
   } 
 
} 
 
public void RasterImageViewer_HScroll(string title) 
{ 
   MyForm3 form = new MyForm3(title); 
   form.ShowDialog(); 
} 
 
static class LEAD_VARS 
{ 
public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
}