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HasCache Property

Summary

Indicates whether this LEADDocument is using the cache.

Syntax
C#
C++/CLI
Java
Python
public bool HasCache {get;} 
public:  
   property bool HasCache 
   { 
      bool get() 
   } 
public boolean hasCache() 
HasCache # get  (LEADDocument) 

Property Value

true if this document uses the cache system; otherwise, false.

Remarks

Documents can contain a large number of pages and a huge amount of data. Storing all this data in the physical memory is not feasible, in most situations. Therefore, the LEADDocument class was designed to use an external caching system to store the modified data. Refer to DocumentFactory.Cache for more information.

HasCache determines if this document is using the cache system. SaveToCache can be used to save a document to the cache and it can be re-loaded using DocumentFactory.LoadFromCache. AutoDeleteFromCache and AutoSaveToCache can be used to determine what happens to the cache data associated with the document when it is disposed.

Example
C#
using Leadtools; 
using Leadtools.Caching; 
using Leadtools.Document; 
 
 
public void DocumentExample() 
{ 
   var cache = GetCache(); 
 
   var policy = new CacheItemPolicy(); 
   policy.AbsoluteExpiration = DateTime.Now + new TimeSpan(0, 0, 1); 
   policy.SlidingExpiration = new TimeSpan(0, 0, 1); 
 
   var options = new LoadDocumentOptions(); 
   options.CachePolicy = policy; 
   options.Cache = cache; 
 
   if(options.Cache == null) 
   { 
      options.Cache = DocumentFactory.Cache; 
   } 
 
   string documentId = null; 
 
   using (var document = DocumentFactory.LoadFromFile(Path.Combine(LEAD_VARS.ImagesDir, "Leadtools.pdf"), options)) 
   { 
      document.GetDocumentFileName(); 
      document.IsReadOnly = false; 
      document.AutoDeleteFromCache = false; 
      // DocumentImages reference 
      document.Images.DefaultBitsPerPixel = 24; 
 
      Console.WriteLine(document.Images.IsResolutionsSupported); 
      Console.WriteLine(document.Images.IsSvgSupported); 
 
      // Check if the document has a stream in memory 
      if (document.HasStream) 
      { 
         // Get the document stream 
         document.GetDocumentStream(); 
      } 
 
      // Indicate whether the document is using the cache or not 
      Console.WriteLine(document.HasCache); 
             
      //Indicate if the document was downloaded 
      Console.WriteLine(document.IsDownloaded); 
 
      // Gets a value that determines whether the document structure is supported 
      Console.WriteLine(document.IsStructureSupported); 
 
      // Output metadata values (DocumentMetadata reference) 
      Console.WriteLine(document.Metadata.Values.Count); 
 
      // Get the Mime type of the document 
      Console.WriteLine(document.MimeType); 
 
      // Parse document structure data (DocumentStructure reference) 
      foreach(DocumentBookmark bookmark in document.Structure.Bookmarks) 
      { 
         bookmark.Title = null; 
         bookmark.FontStyles = DocumentFontStyles.Normal; 
         document.Structure.Bookmarks.Add(bookmark); 
         Console.WriteLine(bookmark.Children); 
         Console.WriteLine(bookmark.Target); 
         Console.WriteLine(document.Structure.Bookmarks.Count); 
         Console.WriteLine(document.Structure.IsParsed); 
         Console.WriteLine(document.Structure.ParseBookmarks); 
      } 
 
      document.Structure.Parse(); 
 
      // Get the document URI 
      Console.WriteLine(document.Uri); 
 
      // Get each DocumentPage object (DocumentPage & DocumentPages reference) 
      foreach (DocumentPage page in document.Pages) 
      { 
         // Get the page as a raster image at the specified resolution 
         page.GetImage(0); 
         // Get the page as an Svg with specified options 
         page.GetSvg(null); 
         // Flip this page horizontally 
         page.Reverse(); 
         // Use this method to add an array of links for this page 
         page.SetLinks(null); 
         page.IsLinksModified = false; 
         page.Resolution = 0; 
         page.ViewPerspective = RasterViewPerspective.TopLeft; 
         page.SetLinks(page.GetLinks()); 
         Console.WriteLine($"Page Number: {page.PageNumber}, Original PageNumber: {page.OriginalPageNumber}, Size of the page: {page.Size}"); 
      } 
 
      PrintOutDocumentInfo(document); 
 
      documentId = document.DocumentId; 
      document.SaveToCache(); 
   } 
 
   System.Threading.Thread.Sleep(2000); 
 
   var loadFromCacheOptions = new LoadFromCacheOptions(); 
   loadFromCacheOptions.Cache = cache; 
   loadFromCacheOptions.DocumentId = documentId; 
   using (var document = DocumentFactory.LoadFromCache(loadFromCacheOptions)) 
   { 
      if (null == document) 
      { 
         Console.WriteLine("Cached document was expired and deleted!"); 
      } 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
} 
Requirements

Target Platforms

Help Version 22.0.2023.4.21
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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

Leadtools.Document Assembly
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.