LoadOptions(string) Method

Summary

Loads the options into this RasterCodecs from a disk file.

Syntax

C++

public void LoadOptions( 
   string fileName 
)

Public Overloads Sub LoadOptions( _ 
   ByVal fileName As String _ 
)

public: 
void LoadOptions(  
   String^ fileName 
)

Parameters

fileName
A String that contains the name of a disk file containing the options to load

Remarks

The RasterCodecs options can be easily saved to a disk or stream using SaveOptions(string fileName) or SaveOptions(Stream stream) and then loaded back into the same or a different RasterCodecs object using LoadOptions(string fileName) or LoadOptions(Stream stream).

Saving and loading the options is handy for situations where a RasterCodecs with specialized options other than the default is used. For example, in a server application as demonstrated by the example.

The options are saved in a standard XML file (with UTF-8 encoding) in the following format:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> 
<leadtools_raster_codecs> 
  <options> 
     <option FullPropertyName="value" /> 
  </options> 
</leadtools_raster_codecs>

FullPropertyName is the exact .NET property name of the options as accessed by the RasterCodecs object, for example, if you have a RasterCodecs object called rasterCodecsInstance, then you can access the CodecsRasterizeDocumentLoadOptions.XResolution using:

rasterCodecsInstance.RasterizeDocument.Load.XResolution

And hence, the FullPropertyName if this option will be RasterizeDocument.Load.XResolution.

The LoadOptions(string fileName) and LoadOptions(Stream stream) methods will merge the content of the XML file with the current RasterCodecs options. Therefore, you can delete any option elements that do not override the default behavior from the file if desired.

Example

This example shows how to save the options and then load them in a server application.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
// A bare-boned REST service that loads an image from a URL and returns it as PNG 
[System.ServiceModel.ServiceContract()] 
public interface ISampleService 
{ 
	[System.ServiceModel.OperationContract(Name = "Load", IsTerminating = false, IsInitiating = true, IsOneWay = false, AsyncPattern = false, Action = "Load")] 
	[System.ServiceModel.Web.WebGet(UriTemplate = "/load?url={url}&page={pageNumber}")] 
	System.IO.Stream Load(string url, int pageNumber); 
} 
 
// Implementation 
public class SampleService : ISampleService 
{ 
	// This is the REST service call 
	public System.IO.Stream Load(string url, int pageNumber) 
	{ 
		// Load the page 
		using (RasterCodecs rasterCodecs = new RasterCodecs()) 
		{ 
			// Get the name of the options file from the configuraion file 
			string optionsFilePath = System.Configuration.ConfigurationManager.AppSettings["RasterCodecsOptionsFilePath"]; 
 
			// See if it is set and contains a valid file 
			if (optionsFilePath != null && System.IO.File.Exists(optionsFilePath)) 
			{ 
				// Set it, this will use the options previously saved with SampleService.PrepareOptions 
				rasterCodecs.LoadOptions(optionsFilePath); 
			} 
 
			// Now load the image 
			using (RasterImage rasterImage = rasterCodecs.Load(new Uri(url), pageNumber)) 
			{ 
				// Save it as PNG 
				System.IO.MemoryStream ms = new System.IO.MemoryStream(); 
				rasterCodecs.Save(rasterImage, ms, RasterImageFormat.Png, 24); 
 
				// Set the content length and MIME type 
				System.ServiceModel.Web.WebOperationContext.Current.OutgoingResponse.ContentType = "image/png"; 
				System.ServiceModel.Web.WebOperationContext.Current.OutgoingResponse.ContentLength = ms.Length; 
 
				ms.Position = 0; 
				return ms; 
			} 
		} 
	} 
 
	// This is a helper method to create the RasterCodecs options file. This method 
	// is meant to be called from ourside the service by an administrator. 
	// 
	// We can change any option we want off-line and then save the file 
	// Our service will pick up the new options from the file and use them 
	public static void PrepareOptions() 
	{ 
		// Get the name of the options file from the configuraion file 
		string optionsFilePath = System.Configuration.ConfigurationManager.AppSettings["RasterCodecsOptionsFilePath"]; 
 
		// See if it is set 
		if (optionsFilePath != null) 
		{ 
			// Yes, create a new RasterCodecs object 
			using (RasterCodecs rasterCodecs = new RasterCodecs()) 
			{ 
				// Change any options, for example, set the default resolution for document files ... 
				rasterCodecs.Options.RasterizeDocument.Load.XResolution = 300; 
				rasterCodecs.Options.RasterizeDocument.Load.YResolution = 300; 
				// And enable loading text files as RasterImage support 
				rasterCodecs.Options.Txt.Load.Enabled = true; 
 
				// Save the options to the file specified by the config 
				rasterCodecs.SaveOptions(optionsFilePath); 
			} 
		} 
	} 
}

Requirements

Target Platforms

Reference

RasterCodecs Class

RasterCodecs Members

Overload List

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Help Version 21.0.2021.7.2