Cache results
Caching saves rendering results to a specified location, such as a local disk. When you re-request the rendering results, GroupDocs.Viewer does not render again, but uses the cached results. As a document can take a long time to render, use caching if you expect to reuse the rendering results.
To enable caching, follow these steps:
- Instantiate the desired cache object (for example, FileCache to store document rendering results at the local drive)
- Instantiate the ViewerSettings object. Specify the cache object as a parameter of the constructor.
- Instantiate the Viewer object. Specify the ViewerSettings object as a parameter of the constructor.
- Call the View method of the Viewer class.
The following code snippet shows how to enable caching and displays the difference between rendering a file and getting the cached results:
using System;
using System.Diagnostics;
using System.IO;
using GroupDocs.Viewer;
using GroupDocs.Viewer.Caching;
using GroupDocs.Viewer.Options;
// ...
string outputDirectory = @"C:\output";
string cachePath = Path.Combine(outputDirectory, "cache");
string pageFilePathFormat = Path.Combine(outputDirectory, "page_{0}.html");
// Create a cache.
FileCache cache = new FileCache(cachePath);
ViewerSettings settings = new ViewerSettings(cache);
using (Viewer viewer = new Viewer(@"C:\sample.docx", settings))
{
// Create an HTML file.
HtmlViewOptions options = HtmlViewOptions.ForEmbeddedResources(pageFilePathFormat);
// Render and display the rendering time.
Stopwatch stopWatch = Stopwatch.StartNew();
viewer.View(options);
stopWatch.Stop();
Console.WriteLine("Time taken on first call to View method {0} (ms).", stopWatch.ElapsedMilliseconds);
// Get cached results and display the time.
stopWatch.Restart();
viewer.View(options);
stopWatch.Stop();
Console.WriteLine("Time taken on second call to View method {0} (ms).", stopWatch.ElapsedMilliseconds);
}
Imports System
Imports System.Diagnostics
Imports System.IO
Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Caching
Imports GroupDocs.Viewer.Options
' ...
Module Program
Sub Main(args As String())
Dim outputDirectory As String = "C:\output"
Dim cachePath As String = Path.Combine(outputDirectory, "cache")
Dim pageFilePathFormat As String = Path.Combine(outputDirectory, "page_{0}.html")
' Create a cache.
Dim cache As FileCache = New FileCache(cachePath)
Dim settings As ViewerSettings = New ViewerSettings(cache)
Using viewer As Viewer = New Viewer("C:\sample.docx", settings)
' Create an HTML file.
Dim options As HtmlViewOptions = HtmlViewOptions.ForEmbeddedResources(pageFilePathFormat)
' Render and display the rendering time.
Dim stopWatch As Stopwatch = Stopwatch.StartNew()
viewer.View(options)
stopWatch.[Stop]()
Console.WriteLine("Time taken on first call to View method {0} (ms).", stopWatch.ElapsedMilliseconds)
' Get cached results and display the time.
stopWatch.Restart()
viewer.View(options)
stopWatch.[Stop]()
Console.WriteLine("Time taken on second call to View method {0} (ms).", stopWatch.ElapsedMilliseconds)
End Using
End Sub
End Module
CONVERSION ERROR: Conversion for GlobalStatement not implemented, please report this issue in 'string outputDirectory = @"...' at character 160
CONVERSION ERROR: Conversion for GlobalStatement not implemented, please report this issue in 'string cachePath = Path.Com...' at character 200
CONVERSION ERROR: Conversion for GlobalStatement not implemented, please report this issue in 'string pageFilePathFormat =...' at character 260
CONVERSION ERROR: Conversion for GlobalStatement not implemented, please report this issue in 'FileCache cache = new FileC...' at character 357
CONVERSION ERROR: Conversion for GlobalStatement not implemented, please report this issue in 'ViewerSettings settings = n...' at character 402
CONVERSION ERROR: Conversion for GlobalStatement not implemented, please report this issue in 'using (Viewer viewer = new ...' at character 458
The following image shows a sample console output:
For details, please refer to the following pages:
