StopFeedLoad Method

Summary

Ends a file-load process in which you control the input stream.

Syntax

Objective-C

C++/CLI

Java

Python

public RasterImage StopFeedLoad()

- (nullable LTRasterImage *)stopFeedLoad:(NSError **)error

public RasterImage stopFeedLoad()

public: 
RasterImage^ StopFeedLoad();

def StopFeedLoad(self):

Return Value

The image loaded by the FeedLoad process.

Remarks

This cleans up all the variables and buffers allocated by the StartFeedLoad and FeedLoad methods and resets all internal variables to their default settings.

You must call this method to complete a file load that was started with StartFeedLoad.

If you call this method before supplying the complete file, it will successfully clean up the process, but will throw a file-read exception. You should trap the error if the load is canceled purposely.

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

Example

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
public void FeedLoadExample() 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
 
   codecs.CancelFeedLoad(); 
 
   string url = @"https://www.leadtools.com/images/page_graphics/leadlogo.png"; 
   string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "FeedLoad.bmp"); 
 
   // Create a WebRequest for the URL 
   WebRequest request = WebRequest.Create(url); 
   request.Proxy.Credentials = CredentialCache.DefaultCredentials; 
 
   // reduce the timeout to 20sec 
   request.Timeout = 20000; 
 
   WebResponse response = request.GetResponse(); 
   try 
   { 
      Stream strm = response.GetResponseStream(); 
 
      // Read chunks from the stream and feed load to the image 
      codecs.StartFeedLoad(0, CodecsLoadByteOrder.BgrOrGray); 
 
      const int bufferSize = 1024; 
      byte[] buffer = new byte[bufferSize]; 
 
      int read; 
 
      do 
      { 
         System.Windows.Forms.Application.DoEvents(); 
 
         read = strm.Read(buffer, 0, bufferSize); 
         Debug.WriteLine("Downloading {0} bytes", read); 
         if (read > 0) 
            codecs.FeedLoad(buffer, 0, read); 
      } 
      while (read > 0); 
   } 
   finally 
   { 
      response.Close(); 
   } 
 
   RasterImage image = codecs.StopFeedLoad(); 
 
   // Save the image to disk 
   codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24); 
   image.Dispose(); 
 
   // Clean up 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

 
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 feedLoadExample() throws IOException { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   RasterCodecs codecs = new RasterCodecs(); 
 
   URL url = new URL("https://www.leadtools.com/images/page_graphics/leadlogo.png"); 
   String destFileName = combine(LEAD_VARS_IMAGES_DIR, "FeedLoad.bmp"); 
 
   // 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 requestInput = con.getInputStream(); 
 
      // Read chunks from the stream and feed load to the image 
      feedLoad = codecs.startFeedLoad(0, CodecsLoadByteOrder.BGR_OR_GRAY); 
 
      final int bufferSize = 1024; 
      byte[] buffer = new byte[bufferSize]; 
 
      int read; 
      do { 
         read = requestInput.read(buffer, 0, bufferSize); 
         System.out.println("Downloading " + read + " bytes"); 
         if (read > 0) 
            feedLoad.feedLoad(buffer, 0, read); 
      } while (read > 0); 
      requestInput.close(); 
   } finally { 
      con.disconnect(); 
   } 
 
   RasterImage image = feedLoad.stopFeedLoad(); 
 
   // Save the image to disk 
   codecs.save(image, destFileName, RasterImageFormat.BMP, 24); 
   assertTrue("Image unsuccessfully saved", (new File(destFileName)).exists()); 
   System.out.println("Saved image at" + destFileName); 
 
   // Clean up 
   image.dispose(); 
   codecs.dispose(); 
}