Update Metadata of your PDF documents programmatically using a REST API in C#.

EditMetadataPDF_NET

Edit Metadata of PDF Documents
1. Programmatically upload a PDF file on the cloud
2. Update Metadata of PDF Documents programmatically on the cloud using a REST API in C#. 
3. Download the updated file from the cloud.

EditMetadataPDF_NET_AddClientIDandSecret.cs

string clientID = "112f0f38-9dae-42d5-b4fc-cc84ae644972";
string clientSecret = "16ad3fe0bdc39c910f57d2fd48a5d618";
string myStorage = "";

Configuration configuration = new Configuration(clientID, clientSecret);
configuration.ApiBaseUrl = "https://api.groupdocs.cloud";

EditMetadataPDF_NET_DownloadFile.cs

# api initialization
var fileApi = new FileApi(configuration);
var file = "metadata\\set_metadata\\input_pdf\\input.pdf";
var downloadRequest = new DownloadFileRequest(file, myStorage);

Stream downloadResponse = fileApi.DownloadFile(downloadRequest);
using (var fileStream = File.Create("C:\\Files\\sample_input.pdf"))
{
    downloadResponse.Seek(0, SeekOrigin.Begin);
    downloadResponse.CopyTo(fileStream);
}

EditMetadataPDF_NET_MatchExactPhrase.cs

# api initialization
var apiInstance = new MetadataApi(configuration);
var fileInfo = new GroupDocs.Metadata.Cloud.Sdk.Model.FileInfo
{
    FilePath = "input.pdf",
    StorageName = myStorage
};

// Define Set Options
var options = new SetOptions
{
    FileInfo = fileInfo,
    Properties = new List<SetProperty>
    {
        new SetProperty
        {
            NewValue = "This is title",
            Type = "String",
            SearchCriteria = new SearchCriteria
            {
                NameOptions = new NameOptions
                {
                    Value = "Title",
                    MatchOptions = new MatchOptions
                    {
                        ExactPhrase = true
                    }
                }
            },
        }
    }
};

// Define Set Request
var request = new SetRequest(options);

var response = apiInstance.Set(request);

EditMetadataPDF_NET_MatchRegex.cs

# api initialization
var apiInstance = new MetadataApi(configuration);
var fileInfo = new GroupDocs.Metadata.Cloud.Sdk.Model.FileInfo
{
    FilePath = "input.pdf",
    StorageName = myStorage
};

// Define Set Options
var options = new SetOptions
{
    FileInfo = fileInfo,
    Properties = new List<SetProperty>
    {
        new SetProperty
        {
            NewValue = "new value",
            Type = "String",
            SearchCriteria = new SearchCriteria
            {
                NameOptions = new NameOptions
                {
                    Value = "^Tit.*",
                    MatchOptions = new MatchOptions
                    {
                        IsRegex = true
                    }
                }
            },
        }
    }
};

// Define Set Request
var request = new SetRequest(options);

var response = apiInstance.Set(request);

EditMetadataPDF_NET_MetaValue.cs

# api initialization
var apiInstance = new MetadataApi(configuration);
var fileInfo = new GroupDocs.Metadata.Cloud.Sdk.Model.FileInfo
{
    FilePath = "input.pdf",
    StorageName = myStorage
};

// Define Set Options
var options = new SetOptions
{
    FileInfo = fileInfo,
    Properties = new List<SetProperty>
    {
        new SetProperty
        {
            NewValue = "Simply set by Property Value",
            Type = "String",
            SearchCriteria = new SearchCriteria
            {
                ValueOptions = new ValueOptions
                {
                    Value = "Windows User",
                    Type = "String"
                }
            },
        }
    }
};

// Define Set Request
var request = new SetRequest(options);

var response = apiInstance.Set(request);

EditMetadataPDF_NET_SetMetadata.cs

# api initialization
var apiInstance = new MetadataApi(configuration);

try
{
    var fileInfo = new GroupDocs.Metadata.Cloud.Sdk.Model.FileInfo
    {
        FilePath = "input.pdf",
        StorageName = myStorage
    };
    
    // Define Set Options
    var options = new SetOptions
    {
        FileInfo = fileInfo,
        Properties = new List<SetProperty>
        {
            new SetProperty
            {
                NewValue = "hello",
                Type = "String",
                SearchCriteria = new SearchCriteria
                {
                    NameOptions = new NameOptions
                    {
                        Value = "Keywords"
                    }
                },
            }
        }
    };
    
    // Define Set Request
    var request = new SetRequest(options);

    var response = apiInstance.Set(request);
    Console.WriteLine($"Count of changes: {response.SetCount}");
    Console.WriteLine("Resultant file path: " + response.Path);
}
catch (Exception e)
{
    Console.WriteLine("Exception while calling MetadataApi: " + e.Message);
}

EditMetadataPDF_NET_UploadFile.cs

# api initialization
FileApi fileApi = new FileApi(configuration);
string path = @"C:\Files";

var file = Directory.GetFiles(path, "input.pdf", SearchOption.AllDirectories).FirstOrDefault();
if (file.Length != 0)
{
    var relativeFilePath = file.Replace(path, string.Empty).Trim(Path.DirectorySeparatorChar);

    var fileStream = File.Open(file, FileMode.Open);

    fileApi.UploadFile(new UploadFileRequest(relativeFilePath, fileStream, myStorage));
    fileStream.Close();
}