How to identify the corrupted PDF document using C# and VB.NET?

using Syncfusion.Pdf;
using Syncfusion.Pdf.Parsing;
using System.Drawing;

Imports Syncfusion.Pdf
Imports Syncfusion.Pdf.Parsing
Imports System.Drawing

private bool IsCorrupted(string file)
{
    bool isCorrupt = false;
    // Creates an instance of memory stream 
    MemoryStream stream = new MemoryStream();
    try
    {
        // Determine syntax issues
        PdfLoadedDocument ldoc = new PdfLoadedDocument(file);
        foreach (PdfLoadedPage lPage in ldoc.Pages)
        {
            // Determine content and font-related issues
            ExtractText(lPage);
        }
        foreach (PdfLoadedPage lPage in ldoc.Pages)
        {
            // Determine image-related corruptions
            ExtractImage(lPage);
        }
        // Determine structural-related corruptions
        ldoc.FileStructure.IncrementalUpdate = false;
        // Save the PDF document
        ldoc.Save(stream);
        // Close the PDF document
        ldoc.Close(true);
    }
    catch (Exception e)
    {
        isCorrupt = true;
    }
    finally
    {
        // Dispose of the memory stream             
        stream.Dispose();
    }
    return isCorrupt;
}

Private Function IsCorrupted(file As String) As Boolean
    Dim isCorrupt As Boolean = False
    ' Creates an instance of memory stream
    Dim stream As New MemoryStream()
    Try
        ' Determine syntax issues
        Dim ldoc As New PdfLoadedDocument(file)
        For Each lPage As PdfLoadedPage In ldoc.Pages
            ' Determine content and font-related issues
            ExtractText(lPage)
        Next
        For Each lPage As PdfLoadedPage In ldoc.Pages
            ' Determine image-related corruptions
            ExtractImage(lPage)
        Next
        ' Determine structural-related corruptions
        ldoc.FileStructure.IncrementalUpdate = False
        ' Save the PDF document
        ldoc.Save(stream)
        ' Close the PDF document
        ldoc.Close(True)
    Catch e As Exception
        isCorrupt = True
    Finally
        ' Dispose of the memory stream               
        stream.Dispose()
    End Try
    Return isCorrupt
End Function

private void ExtractText(PdfLoadedPage lPage)
{
    // Extract text
    string text = lPage.ExtractText();
    text = null;
}
private void ExtractImage(PdfLoadedPage lPage)
{
    // Extract images
    Image[] image = lPage.ExtractImages();
    if (image != null)
    {
        for (int i = 0; i < image.Length; i++)
            image[i].Dispose();
    }
    image = null;
}

Private Sub ExtractText(lPage As PdfLoadedPage)
    'Extract text
    Dim text As String = lPage.ExtractText()
    text = Nothing
End Sub
 
Private Sub ExtractImage(lPage As PdfLoadedPage)
    'Extract images
    Dim image As Image() = lPage.ExtractImages()
    If image IsNot Nothing Then
        For i As Integer = 0 To image.Length - 1
            image(i).Dispose()
        Next
    End If
    image = Nothing
End Sub