CancelFeedGetInformation Method

Summary

This method can be used to purposefully cancel the feed information process.

Syntax

Objective-C

C++/CLI

Java

Python

public void CancelFeedGetInformation()

- (void)cancelFeedGetInformation

public void cancelFeedGetInformation()

public: 
void CancelFeedGetInformation();

def CancelFeedGetInformation(self):

Remarks

This method can be used to gracefully cancel a feed information operation. For example, during feed information progressing, the user might click a cancel button to abort the operation. You can then call this method to end the feed information process without throwing an exception.

For a description of how the methods relate to each other, refer to StartFeedGetInformation.

Example

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
public void FeedGetInformationExample() 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
 
   codecs.CancelFeedGetInformation(); 
 
   string url = @"https://www.leadtools.com/images/page_graphics/leadlogo.png"; 
 
   // Create a WebRequest for the URL 
   WebRequest request = WebRequest.Create(url); 
   request.Proxy.Credentials = CredentialCache.DefaultCredentials; 
 
   // reduce the timeout to 20 sec 
   request.Timeout = 20000; 
 
   WebResponse response = request.GetResponse(); 
 
   try 
   { 
      Stream strm = response.GetResponseStream(); 
 
      // Read chunks from the stream and feed load to the image 
      codecs.StartFeedGetInformation(true, 1); 
 
      const int bufferSize = 1024; 
      byte[] buffer = new byte[bufferSize]; 
 
      bool more; 
 
      do 
      { 
         System.Windows.Forms.Application.DoEvents(); 
 
         int read = strm.Read(buffer, 0, bufferSize); 
         Debug.WriteLine("Downloading {0} bytes", read); 
         if (read > 0) 
            more = codecs.FeedGetInformation(buffer, 0, read); 
         else 
         { 
            // no more image data in the stream 
            more = false; 
         } 
      } 
      while (more); 
   } 
   finally 
   { 
      response.Close(); 
   } 
 
   CodecsImageInfo info = codecs.StopFeedGetInformation(); 
 
   // Clean up 
   codecs.Dispose(); 
 
   // Show the information 
   Debug.WriteLine(info.ToString()); 
}

 
import java.io.*; 
import java.net.*; 
import java.nio.file.Paths; 
import java.util.*; 
import java.time.Instant; 
import java.time.Duration; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.codecs.*; 
import leadtools.codecs.RasterCodecs.FeedCallbackThunk; 
import leadtools.drawing.internal.*; 
import leadtools.imageprocessing.*; 
import leadtools.imageprocessing.color.ChangeIntensityCommand; 
import leadtools.svg.*; 
 
 
public void feedGetInformationExample() throws IOException { 
   RasterCodecs codecs = new RasterCodecs(); 
   URL url = new URL("https://www.leadtools.com/images/page_graphics/leadlogo.png"); 
 
   // Create a WebRequest for the URL 
   HttpURLConnection con = (HttpURLConnection) url.openConnection(); 
   con.setRequestMethod("GET"); 
   con.setDefaultUseCaches(true); 
 
   // reduce the timeout to 20sec 
   con.setConnectTimeout(20000); 
   con.setReadTimeout(20000); 
   con.getResponseCode(); 
 
   FeedCallbackThunk feedLoad; 
   try { 
      InputStream inputStream = con.getInputStream(); 
 
      // Read chunks from the stream and feed load to the image 
      feedLoad = codecs.startFeedGetInformation(true, 1); 
 
      final int bufferSize = 1024; 
      byte[] buffer = new byte[bufferSize]; 
 
      boolean more; 
 
      do { 
         int read = inputStream.read(buffer, 0, bufferSize); 
         System.out.println("Downloading " + read + " bytes"); 
         if (read > 0) 
            more = feedLoad.feedGetInformation(buffer, 0, read); 
         else { 
            // no more image data in the stream 
            more = false; 
         } 
      } while (more); 
   } finally { 
      con.disconnect(); 
   } 
 
   CodecsImageInfo info = feedLoad.stopFeedGetInformation(); 
 
   // Clean up 
   codecs.dispose(); 
 
   // Show the information 
   assertTrue("The URL is invalid (null)", url != null); 
   System.out.println(info.toString()); 
}

Requirements

Target Platforms

Reference

RasterCodecs Class

RasterCodecs Members

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Help Version 23.0.2024.2.29

Leadtools.Codecs Assembly

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