RasterException Class

The exception that is thrown when a LEADTOOLS error occurs.

Object Model

Syntax

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

[SerializableAttribute()]
public class RasterException : LeadtoolsException, System.Runtime.InteropServices._Exception, System.Runtime.Serialization.ISerializable

'Declaration
 
<SerializableAttribute()>
Public Class RasterException 
   Inherits LeadtoolsException
   Implements System.Runtime.InteropServices._Exception, System.Runtime.Serialization.ISerializable

'Usage
 
Dim instance As RasterException

public sealed class RasterException : System.Runtime.InteropServices._Exception, ~Remove~

function Leadtools.RasterException()

[SerializableAttribute()]
public ref class RasterException : public LeadtoolsException, System.Runtime.InteropServices._Exception, System.Runtime.Serialization.ISerializable

Remarks

The RasterException class defines a Code property that can be examined to determine what caused the error.

Default messages are implemented for each Code. Get the message by calling the GetCodeMessage method.

Example

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Public Sub Example()
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   ' Prompt the user for an image
   Dim dlg As OpenFileDialog = New OpenFileDialog()
   dlg.Filter = "All Files|*.*"
   If dlg.ShowDialog() = DialogResult.OK Then
      ' Try to load this image
      Try
         Dim img As RasterImage = codecs.Load(dlg.FileName)
         MessageBox.Show(String.Format("Image in file {0} is loaded", dlg.FileName))
         img.Dispose()
      Catch ex As RasterException
         ' See if LEADTOOLS could not recognize this image format
         If ex.Code = RasterExceptionCode.FileFormat Then
            MessageBox.Show(String.Format("File {0} does not contain an image format recognizable by LEADTOOLS", dlg.FileName))
         Else
            ' Other LEADTOOLS error (file might be corrupted, read error, etc)
            MessageBox.Show(String.Format("Could not load the file {0}.{1}Leadtools code: {2}{1}Message: {3}", dlg.FileName, Environment.NewLine, ex.Code, ex.Message))
         End If
      Catch ex As Exception
         ' Other errors
         MessageBox.Show(String.Format("Could not load the file {0}.{1}{2}", dlg.FileName, Environment.NewLine, ex.Message))
      End Try
   End If
End Sub

public void Example()
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;

   // Prompt the user for an image
   OpenFileDialog dlg = new OpenFileDialog();
   dlg.Filter = "All Files|*.*";
   if(dlg.ShowDialog() == DialogResult.OK)
   {
      // Try to load this image
      try
      {
         RasterImage img = codecs.Load(dlg.FileName);
         MessageBox.Show(string.Format("Image in file {0} is loaded", dlg.FileName));
         img.Dispose();
      }
      catch(RasterException ex)
      {
         // See if LEADTOOLS could not recognize this image format
         if(ex.Code == RasterExceptionCode.FileFormat)
            MessageBox.Show(string.Format("File {0} does not contain an image format recognizable by LEADTOOLS", dlg.FileName));
         else
         {
            // Other LEADTOOLS error (file might be corrupted, read error, etc)
            MessageBox.Show(string.Format("Could not load the file {0}.{1}Leadtools code: {2}{1}Message: {3}", dlg.FileName, Environment.NewLine, ex.Code, ex.Message));
         }
      }
      catch(Exception ex)
      {
         // Other errors
         MessageBox.Show(string.Format("Could not load the file {0}.{1}{2}", dlg.FileName, Environment.NewLine, ex.Message));
      }
   }
}

function RasterExceptionExamples()
{
   with (Leadtools) {
      with (Leadtools.Codecs) {

         //comment this line to actually get an error on load!
         Tools.SetLicense();

         var codecs = new RasterCodecs();
         codecs.throwExceptionsOnInvalidImages = true;

         Tools.AppInstallFolder().getFileAsync("Assets\\" + "leadtools.jpg").then(function (storageFile) {
            var leadStream = LeadStreamFactory.create(storageFile);

            // Try to load this image
            try {
               codecs.loadAsync(leadStream).then(function (img) {
                  console.log("Image in file " + storageFile.name + " is loaded");
                  img.close();
               }, function (error) { LoadFileErrorHandler(error, storageFile); });

            }
            catch (error) {
               LoadFileErrorHandler(error, storageFile);
            }
         });
      }
   }
}

function LoadFileErrorHandler(error, storageFile)
{
   var errorMessage = null;
   var rasterException = Leadtools.RasterException.fromHResult(error.number);

   if (rasterException) {
      // See if LEADTOOLS could not recognize this image format
      if (rasterException.code == Leadtools.RasterExceptionCode.fileFormat)
         errorMessage = "File " + storageFile.name + " does not contain an image format recognizable by LEADTOOLS";
      else {
         // Other LEADTOOLS error (file might be corrupted, read error, etc)
         errorMessage = "LEADTOOLS Error: " + rasterException.code + "\n" + rasterException.message;
      }
   }
   else {
      // Other errors
      errorMessage = error.message;
   }
   console.error(errorMessage);
}

[TestMethod]
public async Task RasterExceptionExample()
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   StorageFile storageFile = await Tools.AppInstallFolder.GetFileAsync(@"Assets\" + "leadtools.jpg");
   ILeadStream leadStream = LeadStreamFactory.Create(storageFile);

   // Try to load this image
   try
   {
      using (RasterImage img = await codecs.LoadAsync(leadStream))
      {
         Debug.WriteLine(string.Format("Image in file {0} is loaded", storageFile.Name));
      }
   }
   catch(Exception error)
   {
      String errorMessage = null;
      RasterException rasterException = RasterException.FromHResult(error.HResult);
      if (rasterException != null)
      {
         // See if LEADTOOLS could not recognize this image format
         if(rasterException.Code == RasterExceptionCode.FileFormat)
            errorMessage = string.Format("File {0} does not contain an image format recognizable by LEADTOOLS", storageFile.Name);
         else
         {
            // Other LEADTOOLS error (file might be corrupted, read error, etc)
            errorMessage = string.Format("LEADTOOLS Error: {0}\n{1}", rasterException.Code, rasterException.Message);
         }
      }
      else
      {
         // Other errors
         errorMessage = error.Message;
      }
      Debug.WriteLine(errorMessage);
      Assert.Fail(errorMessage);
   }
}

public void Example()
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   // Prompt the user for an image
   OpenFileDialog dlg = new OpenFileDialog();
   dlg.Filter = "All Files|*.*";
   if(dlg.ShowDialog() == true)
   {
      // Try to load this image
      try
      {
         using (FileStream fs = dlg.File.OpenRead())
         {
            RasterImage img = codecs.Load(fs);
            MessageBox.Show(string.Format("Image in file {0} is loaded", dlg.File.FullName));
            img.Dispose();
         }
      }
      catch(RasterException ex)
      {
         // See if LEADTOOLS could not recognize this image format
         if(ex.Code == RasterExceptionCode.FileFormat)
            MessageBox.Show(string.Format("File {0} does not contain an image format recognizable by LEADTOOLS", dlg.File.FullName));
         else
         {
            // Other LEADTOOLS error (file might be corrupted, read error, etc)
            MessageBox.Show(string.Format("Could not load the file {0}.{1}Leadtools code: {2}{1}Message: {3}", dlg.File.FullName, Environment.NewLine, ex.Code, ex.Message));
         }
      }
      catch(Exception ex)
      {
         // Other errors
         MessageBox.Show(string.Format("Could not load the file {0}.{1}{2}", dlg.File.FullName, Environment.NewLine, ex.Message));
      }
   }
}

Public Sub Example()
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True
   ' Prompt the user for an image
   Dim dlg As OpenFileDialog = New OpenFileDialog()
   dlg.Filter = "All Files|*.*"
   If dlg.ShowDialog() = True Then
      ' Try to load this image
      Try
         Using fs As FileStream = dlg.File.OpenRead()
            Dim img As RasterImage = codecs.Load(fs)
            MessageBox.Show(String.Format("Image in file {0} is loaded", dlg.File.FullName))
            img.Dispose()
         End Using
      Catch ex As RasterException
         ' See if LEADTOOLS could not recognize this image format
         If ex.Code = RasterExceptionCode.FileFormat Then
            MessageBox.Show(String.Format("File {0} does not contain an image format recognizable by LEADTOOLS", dlg.File.FullName))
         Else
            ' Other LEADTOOLS error (file might be corrupted, read error, etc)
            MessageBox.Show(String.Format("Could not load the file {0}.{1}Leadtools code: {2}{1}Message: {3}", dlg.File.FullName, Environment.NewLine, ex.Code, ex.Message))
         End If
      Catch ex As Exception
         ' Other errors
         MessageBox.Show(String.Format("Could not load the file {0}.{1}{2}", dlg.File.FullName, Environment.NewLine, ex.Message))
      End Try
   End If
End Sub

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

RasterException Members
Leadtools Namespace