ScrollOffset Property

Summary

Scroll offset value.

Syntax

C++/CLI

public virtual LeadPoint ScrollOffset { get; set; }

public:  
   virtual property LeadPoint^ ScrollOffset 
   { 
      LeadPoint^ get() 
      void set(LeadPoint^ value) 
   }

Property Value

The current scroll offset value. The default value is 0,0.

Remarks

Changing the value of this property will fire the PropertyChanged, ScrollOffsetChanged and TransformChanged events.

When the value of ScrollMode is ControlScrollMode contains the current scrollbars offset. When the user clicks and drags on the scrollbars, the value of ScrollOffset (and the scrollbars thumbs) changes accordingly. The minimum value allowed is 0,0 (top-left) and the maximum value allowed is stored in MaximumScrollSize (setting ScrollOffset to MaximumScrollSize will cause the viewer to scroll the view to the bottom-right corner. You can manually pan the image by setting a value in ScrollOffset or calling ScrollBy.

When the value of ScrollMode is ControlScrollMode.Hidden, then the value of ScrollOffset contains the virtual scroll (pan) offset, you can pan the image by changing the value of ScrollOffset or calling ScrollBy. If the value of RestrictScroll is true, then the minimum and maximum scroll values are the same as the case above. If the value of RestrictScroll is false, then there is no minimum and maximum scroll ranges, you are allowed to set ScrollOffset to any value. 0,0 and MaximumScrollSize will still be the values to use if you want to either scroll the image to top-left or right-bottom.

When the value of ScrollMode is ControlScrollMode.Disabled, then trying to change the value of ScrollOffset or calling ScrollBy will be ignored.

For more information, refer to Image Viewer Scrolling.

Example

using Leadtools; 
using Leadtools.Controls; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
 
 
public ImageViewerForm _form = new ImageViewerForm(); 
public ImageViewer _imageViewer; 
 
public void ImageViewerScrollModeExample() 
{ 
   // Get the ImageViewer control 
   _imageViewer = _form.ImageViewer; 
 
   // Load Image 
   using (var codecs = new RasterCodecs()) 
      _imageViewer.Image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif")); 
 
   // Set Zoom Mode to None 
   _imageViewer.Zoom(ControlSizeMode.None, 1.2, _imageViewer.DefaultZoomOrigin); 
 
   // Hook to the ScrollOffset event that triggers when ScrollOffset value is changed 
   _imageViewer.ScrollOffsetChanged += (sender, e) => 
   { 
      Debug.WriteLine("ScrollOffset changed: (" + _imageViewer.ScrollOffset.X + ", " + _imageViewer.ScrollOffset.Y + ")"); 
   }; 
 
   // Set ScrollMode to hidden 
   if (_imageViewer.ScrollMode != ControlScrollMode.Hidden) 
   { 
      _imageViewer.ScrollMode = ControlScrollMode.Hidden; 
      _imageViewer.ScrollOffset = new LeadPoint(100, 100); // Offset the scroll 
      _imageViewer.RestrictScroll = false; 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

Requirements

Target Platforms

Reference

ImageViewer Class

ImageViewer Members

Leadtools.Controls Namespace

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Help Version 23.0.2024.2.29

Leadtools.Controls Assembly

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