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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#
VB
C++
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.

C#
VB
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"; 
} 
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

Requirements

Target Platforms

Help Version 19.0.2017.10.27
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