C#

Extract Embedded Files from PDF

Demonstrates how to get information about the embedded files (if any) contained within a PDF, and shows how to extract each file.

Note: This example requires Chilkat v9.5.0.95 or greater.

C#

bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

Chilkat.Pdf pdf = new Chilkat.Pdf();

success = pdf.LoadFile("qa_data/pdf/embedded_files/my_embedded_files_test.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

//  Note: The embedded file functionality was added in Chilkat v9.5.0.95

//  How many embedded files exist within the opened PDF?
int numFiles = pdf.NumEmbeddedFiles;
Debug.WriteLine("Number of embedded files: " + Convert.ToString(numFiles));

Chilkat.JsonObject json = new Chilkat.JsonObject();
json.EmitCompact = false;

Chilkat.BinData bd = new Chilkat.BinData();

//  Get information about each file, and extract each to the filesystem.
int i = 0;
while (i < numFiles) {

    success = pdf.GetEmbeddedFileInfo(i,json);
    if (success == false) {
        Debug.WriteLine(pdf.LastErrorText);
        return;
    }

    Debug.WriteLine(json.Emit());

    //  Get the filename from the JSON.
    string filename = "someFile.dat";

    //  The filename SHOULD always be present..
    if (json.HasMember("filename") == true) {
        filename = json.StringOf("filename");
    }

    //  Get the file data.
    success = pdf.GetEmbeddedFileBd(i,bd);
    if (success == false) {
        Debug.WriteLine(pdf.LastErrorText);
        return;
    }

    //  Save the contents of the bd to the filename (in the current working directory) in the filesystem.
    success = bd.WriteFile(filename);
    if (success == false) {
        Debug.WriteLine("Failed to write output file.");
    }

    i = i + 1;
}

//  Sample output for the above code:

//  Number of embedded files: 3
//  {
//    "filename": "employees.json",
//    "desc": "JSON",
//    "subType": "application/json",
//    "size": 159,
//    "creationDate": "D:20230715170506-05'00'",
//    "modDate": "D:20160207153838-05'00'"
//  }
//  
//  {
//    "filename": "rsaPubKey.pem",
//    "desc": "RSA Public Key PEM",
//    "size": 451,
//    "creationDate": "D:20230715170546-05'00'",
//    "modDate": "D:20150724133153-05'00'"
//  }
//  
//  {
//    "filename": "starfish.jpg",
//    "desc": "Starfish JPG",
//    "subType": "image/jpeg",
//    "size": 6229,
//    "creationDate": "D:20230715170356-05'00'",
//    "modDate": "D:20080529103055-05'00'"
//  }