IsLoading Property

Summary

Gets a value that determines whether this CodecsImageInfo object is still loading.

Syntax

Objective-C

C++/CLI

Java

Python

public bool IsLoading { get; }

@property (nonatomic, assign, readonly) BOOL isLoading;

public boolean isLoading()

public: 
property bool IsLoading { 
   bool get(); 
}

IsLoading # get  (CodecsImageInfo)

Property Value

true if the image is still loading; false, otherwise. The default value is false.

Remarks

NOTE: This topic is part of RasterCodecs Async support using the .NET System.ComponentMode.AsyncOperation model. For .NET async/await support this type/member is not used. Instead, refer to RasterCodecs Async Operations.

The RasterCodecs class supports getting information on image files asynchronously using the RasterCodecs.GetInformationAsync methods. When calling any of these methods, the caller's thread will not be blocked and the method will return instantly with an instance CodecsImageInfo that is in a loading status (CodecsImageInfo.IsLoading set to true). You should not use the other properties of this object while the object is in loading status.

When the RasterCodecs object finishes getting the information about the file, the various properties of the CodecsImageInfo will be populated with the image file information and the CodecsImageInfo.IsLoading property will be set to false.

It is recommended that you do not poll for the CodecsImageInfo.IsLoading property to determine whether the image information has been collected. Instead, subscribe to the RasterCodecs.GetInformationAsyncCompleted event to get notification on when the GetInformationAsync operation is completed and whether any errors occurred.

The RasterCodecs.GetInformationAsyncCompleted event data will also contain the same object returned from RasterCodecs.GetInformationAsync so you do not have to keep the original object in your application.

Example

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
public void GetInformationAsyncCompletedExample() 
{ 
   string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
   Uri uri = new Uri(srcFileName); 
 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Now get information about the file asynchronously 
   codecs.GetInformationAsyncCompleted += new EventHandler<CodecsGetInformationAsyncCompletedEventArgs>(GetInformationAsyncCompletedExample_GetInformationAsyncCompleted); 
   object imageInfoObject = codecs.GetInformationAsync(uri, true, 1, null); 
 
   // Notice that the returned imageInfoObject is a CodecsImageInfo with IsLoading set to true at this point 
   // The IsLoading will be false (and hence, the object will be usable) when the GetInformationAsyncCompleted 
   // fires. 
} 
 
private void GetInformationAsyncCompletedExample_GetInformationAsyncCompleted(object sender, CodecsGetInformationAsyncCompletedEventArgs e) 
{ 
   if (e.Cancelled) 
   { 
      Debug.WriteLine("User canceled"); 
   } 
   else if (e.Error != null) 
   { 
      Debug.WriteLine("Error: " + e.Error.Message); 
   } 
   else 
   { 
      // Get the image info 
      CodecsImageInfo info = e.Info; 
      Debug.WriteLine("Image info obtainted asynchronously:\n{0}", info.ToString()); 
      info.Dispose(); 
   } 
 
   // Unsubscribe to the event and dispose the RasterCodecs object 
   RasterCodecs codecs = sender as RasterCodecs; 
   codecs.GetInformationAsyncCompleted -= new EventHandler<CodecsGetInformationAsyncCompletedEventArgs>(GetInformationAsyncCompletedExample_GetInformationAsyncCompleted); 
   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 getInformationAsyncCompletedExample() throws URISyntaxException, IOException { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   String srcFileName = combine(LEAD_VARS_IMAGES_DIR, "Image1.cmp"); 
   URI uri = Paths.get(srcFileName).toUri(); 
 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Now get information about the file asynchronously 
   codecs.addGetInformationAsyncCompletedListener(getInformationAsyncCompletedExampleGetInformationAsyncCompleted); 
   ILeadStream uriStream = LeadStreamFactory.create(uri); 
   codecs.getInformationAsync(uriStream, true, 1, null); 
 
   assertTrue("Check that URI exists", uri != null); 
   System.out.println("The URI exists"); 
 
   uriStream.close(); 
} 
 
CodecsGetInformationAsyncCompletedListener getInformationAsyncCompletedExampleGetInformationAsyncCompleted = new CodecsGetInformationAsyncCompletedListener() { 
 
   @Override 
   public void onGetInformationAsyncCompleted(CodecsGetInformationAsyncCompletedEvent e) { 
      if (e.getCancelled()) { 
         System.out.println("User canceled"); 
      } else if (e.getError() != null) { 
         System.out.println("Error: " + e.getError().getMessage()); 
      } else { 
         // Get the image info 
         CodecsImageInfo info = e.getInfo(); 
         System.out.println("Image info obtainted asynchronously:\n" + info.toString()); 
      } 
 
      // Unsubscribe to the event and dispose the RasterCodecs object 
      RasterCodecs codecs = (RasterCodecs) e.getSource(); 
      codecs.removeGetInformationAsyncCompletedListener( 
            getInformationAsyncCompletedExampleGetInformationAsyncCompleted); 
      codecs.dispose(); 
   } 
 
};

Requirements

Target Platforms

Reference

CodecsImageInfo Class

CodecsImageInfo Members

Download our FREE evaluation

Help Version 23.0.2024.2.29