C# Internal (How It Works For Developers)

When managing the visibility of form classes, methods, and properties inside a static void main program, access modifiers are essential in the C# component-based development programming language. When building graphical user interfaces that are modular and maintainable, one such access modifier that is quite relevant is internal. The idea of C# internal will be discussed in this article, along with several useful applications for IronPDF, a flexible C# framework for managing PDF documents.

How to use internal members in C# component-based development

1. Create a C# project.
2. Understand the internal access modifier.
3. Apply 'internal' to members.
4. Organize code at the assembly level.
5. Use internal members within the same assembly.
6. Compile the code.

Understanding the Internal Access Modifier

The internal keyword/access modifier in C# limits a type or member's visibility to that of other members within the same assembly. This implies that any class, whether it be a derived class, method, or property tagged as internal, can be accessed by other types within the same assembly but is unavailable to types outside the assembly. This degree of access control is essential for encapsulation because it lets you specify implementation specifics that should be used exclusively inside the same assembly in a private manner.

In C#, you may use the internal modifier in the following ways:

Internal Class

Declaring a class that is only available within the same assembly by using internal.

// Assembly1
internal class InternalClass
{
    // Members of InternalClass
}

// Assembly1
internal class InternalClass
{
    // Members of InternalClass
}

' Assembly1
Friend Class InternalClass
	' Members of InternalClass
End Class

Internal Class Members

Limiting the visibility of class members, such as fields, properties, and methods, to the same assembly by applying internal.

// Assembly1
internal class MyClass
{
    internal static int InternalField;
    internal void InternalMethod() { }
}

// Assembly1
internal class MyClass
{
    internal static int InternalField;
    internal void InternalMethod() { }
}

' Assembly1
Friend Class [MyClass]
	Friend Shared InternalField As Integer
	Friend Sub InternalMethod()
	End Sub
End Class

Internal Interface

Declaring an interface that can only be accessed within the same assembly by using the internal access modifier.

// Assembly1
internal interface IInternalInterface
{
    // Interface members
}

// Assembly1
internal interface IInternalInterface
{
    // Interface members
}

' Assembly1
Friend Interface IInternalInterface
	' Interface members
End Interface

Internal Nested Class

Declaring a nested class that can only be accessed inside the same assembly using internal.

// Assembly1
public class OuterClass
{
    internal class InternalNestedClass
    {
        // Members of InternalNestedClass
    }
}

// Assembly1
public class OuterClass
{
    internal class InternalNestedClass
    {
        // Members of InternalNestedClass
    }
}

' Assembly1
Public Class OuterClass
	Friend Class InternalNestedClass
		' Members of InternalNestedClass
	End Class
End Class

Internal Assembly

Limiting access to the entire assembly from external assemblies by applying internal at the assembly level.

using System.Runtime.CompilerServices;

// Allowing "ExternalAssembly" to access internal members of this assembly
[assembly: InternalsVisibleTo("ExternalAssembly")]

using System.Runtime.CompilerServices;

// Allowing "ExternalAssembly" to access internal members of this assembly
[assembly: InternalsVisibleTo("ExternalAssembly")]

Imports System.Runtime.CompilerServices

' Allowing "ExternalAssembly" to access internal members of this assembly
<Assembly: InternalsVisibleTo("ExternalAssembly")>

During development and testing, the internal access modifiers can be made accessible to a designated external assembly by using the InternalsVisibleTo attribute.

// Assembly A
public class MyClassA
{
    internal void MyInternalMethod()
    {
        // Implementation details only accessible within Assembly A
    }
}

// Assembly B
public class MyClassB
{
    void SomeMethod()
    {
        MyClassA myObject = new MyClassA();
        myObject.MyInternalMethod(); // This will result in a compilation error
    }
}

// Assembly A
public class MyClassA
{
    internal void MyInternalMethod()
    {
        // Implementation details only accessible within Assembly A
    }
}

// Assembly B
public class MyClassB
{
    void SomeMethod()
    {
        MyClassA myObject = new MyClassA();
        myObject.MyInternalMethod(); // This will result in a compilation error
    }
}

' Assembly A
Public Class MyClassA
	Friend Sub MyInternalMethod()
		' Implementation details only accessible within Assembly A
	End Sub
End Class

' Assembly B
Public Class MyClassB
	Private Sub SomeMethod()
		Dim myObject As New MyClassA()
		myObject.MyInternalMethod() ' This will result in a compilation error
	End Sub
End Class

Since MyInternalMethod is designated as an internal member in this example, it can only be accessed within Assembly A. A compilation error will occur if you try to access this function from Assembly B.

Combining the protected and internal access modifiers results in the protected internal access modifier. A member (method, property, or field) or a type (class, interface, or delegate) can be accessed both inside and outside its assembly by derived types thanks to a protected internal compound access modifier. A balance between the visibility that protected and internal access levels separately give is provided by the protected internal access level.

IronPDF

Using the C# programming language, IronPDF Official Site is a .NET library that enables developers to generate, edit, and modify PDF documents. It offers an array of tools and features to interact with PDF files in many ways, including creating PDFs from HTML, converting HTML to PDF, combining or dividing PDF documents, and appending annotations, text, and photos to already existing PDFs.

Install IronPDF

Get the IronPDF library; it's needed for the future patch. Enter the following command into the Package Manager Console to accomplish this:

Install-Package IronPdf

Using the NuGet Package Manager to search for the package "IronPDF" is an additional choice. We may choose and download the necessary package from this list of all the NuGet packages associated with IronPDF.

IronPDF excels in HTML to PDF conversion, ensuring precise preservation of original layouts and styles. It's perfect for creating PDFs from web-based content such as reports, invoices, and documentation. With support for HTML files, URLs, and raw HTML strings, IronPDF easily produces high-quality PDF documents.

using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();

        // 1. Convert HTML String to PDF
        var htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF from an HTML string.</p>";
        var pdfFromHtmlString = renderer.RenderHtmlAsPdf(htmlContent);
        pdfFromHtmlString.SaveAs("HTMLStringToPDF.pdf");

        // 2. Convert HTML File to PDF
        var htmlFilePath = "path_to_your_html_file.html"; // Specify the path to your HTML file
        var pdfFromHtmlFile = renderer.RenderHtmlFileAsPdf(htmlFilePath);
        pdfFromHtmlFile.SaveAs("HTMLFileToPDF.pdf");

        // 3. Convert URL to PDF
        var url = "http://ironpdf.com"; // Specify the URL
        var pdfFromUrl = renderer.RenderUrlAsPdf(url);
        pdfFromUrl.SaveAs("URLToPDF.pdf");
    }
}

using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();

        // 1. Convert HTML String to PDF
        var htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF from an HTML string.</p>";
        var pdfFromHtmlString = renderer.RenderHtmlAsPdf(htmlContent);
        pdfFromHtmlString.SaveAs("HTMLStringToPDF.pdf");

        // 2. Convert HTML File to PDF
        var htmlFilePath = "path_to_your_html_file.html"; // Specify the path to your HTML file
        var pdfFromHtmlFile = renderer.RenderHtmlFileAsPdf(htmlFilePath);
        pdfFromHtmlFile.SaveAs("HTMLFileToPDF.pdf");

        // 3. Convert URL to PDF
        var url = "http://ironpdf.com"; // Specify the URL
        var pdfFromUrl = renderer.RenderUrlAsPdf(url);
        pdfFromUrl.SaveAs("URLToPDF.pdf");
    }
}

Imports IronPdf

Friend Class Program
	Shared Sub Main(ByVal args() As String)
		Dim renderer = New ChromePdfRenderer()

		' 1. Convert HTML String to PDF
		Dim htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF from an HTML string.</p>"
		Dim pdfFromHtmlString = renderer.RenderHtmlAsPdf(htmlContent)
		pdfFromHtmlString.SaveAs("HTMLStringToPDF.pdf")

		' 2. Convert HTML File to PDF
		Dim htmlFilePath = "path_to_your_html_file.html" ' Specify the path to your HTML file
		Dim pdfFromHtmlFile = renderer.RenderHtmlFileAsPdf(htmlFilePath)
		pdfFromHtmlFile.SaveAs("HTMLFileToPDF.pdf")

		' 3. Convert URL to PDF
		Dim url = "http://ironpdf.com" ' Specify the URL
		Dim pdfFromUrl = renderer.RenderUrlAsPdf(url)
		pdfFromUrl.SaveAs("URLToPDF.pdf")
	End Sub
End Class

Features of IronPDF

• Convert HTML to PDF: With IronPDF, you can create PDF documents from any type of HTML information, including files, URLs, and strings of HTML code.
• PDF Generation: Using the C# programming language, you may add text, graphics, and other components to PDF documents programmatically.
• PDF Manipulation: IronPDF offers capabilities to divide a PDF file into numerous files, combine multiple PDF documents into a single file, and modify already-existing PDFs.
• PDF Forms: The library is helpful in situations where form data needs to be collected and processed since it allows users to create and complete PDF forms.
• Security Features: PDF documents may be password- and permission-protected and encrypted using IronPDF.
• Text Extraction: IronPDF may be used to extract text from PDF files.

Encapsulation of PDF Handling with IronPDF

A vast range of features for generating, modifying, and processing PDF documents are offered by IronPDF. The implementation details can be kept hidden behind assembly borders by enclosing the PDF processing code inside internal classes or methods. To know more about IronPDF, refer to the IronPDF Documentation.

Examine the following situation:

// Assembly A (PDFHandlingLibrary)
internal class PdfProcessor
{
    internal void AddWatermark(IronPdf.PdfDocument pdfDocument, string watermarkText)
    {
        // Implementation details for adding a watermark using IronPDF
    }

    internal IronPdf.PdfDocument MergePdfDocuments(IEnumerable<IronPdf.PdfDocument> pdfDocuments)
    {
        // Implementation details for merging PDF documents using IronPDF
        IronPdf.PdfDocument mergedPdfDocument = new IronPdf.PdfDocument();
        // Logic to merge documents
        return mergedPdfDocument;
    }
}

// Assembly B (MainApplication)
public class MainClass
{
    void ProcessPdfDocuments()
    {
        // Create an instance of the PdfProcessor within the same assembly
        PdfProcessor pdfProcessor = new PdfProcessor();

        // Assuming pdfDocumentList is defined
        IEnumerable<IronPdf.PdfDocument> pdfDocumentList = new List<IronPdf.PdfDocument>();

        // Accessing internal methods within the same assembly is allowed
        pdfProcessor.AddWatermark(new IronPdf.PdfDocument(), "Confidential");
        IronPdf.PdfDocument mergedPdf = pdfProcessor.MergePdfDocuments(pdfDocumentList);
    }
}

// Assembly A (PDFHandlingLibrary)
internal class PdfProcessor
{
    internal void AddWatermark(IronPdf.PdfDocument pdfDocument, string watermarkText)
    {
        // Implementation details for adding a watermark using IronPDF
    }

    internal IronPdf.PdfDocument MergePdfDocuments(IEnumerable<IronPdf.PdfDocument> pdfDocuments)
    {
        // Implementation details for merging PDF documents using IronPDF
        IronPdf.PdfDocument mergedPdfDocument = new IronPdf.PdfDocument();
        // Logic to merge documents
        return mergedPdfDocument;
    }
}

// Assembly B (MainApplication)
public class MainClass
{
    void ProcessPdfDocuments()
    {
        // Create an instance of the PdfProcessor within the same assembly
        PdfProcessor pdfProcessor = new PdfProcessor();

        // Assuming pdfDocumentList is defined
        IEnumerable<IronPdf.PdfDocument> pdfDocumentList = new List<IronPdf.PdfDocument>();

        // Accessing internal methods within the same assembly is allowed
        pdfProcessor.AddWatermark(new IronPdf.PdfDocument(), "Confidential");
        IronPdf.PdfDocument mergedPdf = pdfProcessor.MergePdfDocuments(pdfDocumentList);
    }
}

' Assembly A (PDFHandlingLibrary)
Friend Class PdfProcessor
	Friend Sub AddWatermark(ByVal pdfDocument As IronPdf.PdfDocument, ByVal watermarkText As String)
		' Implementation details for adding a watermark using IronPDF
	End Sub

	Friend Function MergePdfDocuments(ByVal pdfDocuments As IEnumerable(Of IronPdf.PdfDocument)) As IronPdf.PdfDocument
		' Implementation details for merging PDF documents using IronPDF
		Dim mergedPdfDocument As New IronPdf.PdfDocument()
		' Logic to merge documents
		Return mergedPdfDocument
	End Function
End Class

' Assembly B (MainApplication)
Public Class MainClass
	Private Sub ProcessPdfDocuments()
		' Create an instance of the PdfProcessor within the same assembly
		Dim pdfProcessor As New PdfProcessor()

		' Assuming pdfDocumentList is defined
		Dim pdfDocumentList As IEnumerable(Of IronPdf.PdfDocument) = New List(Of IronPdf.PdfDocument)()

		' Accessing internal methods within the same assembly is allowed
		pdfProcessor.AddWatermark(New IronPdf.PdfDocument(), "Confidential")
		Dim mergedPdf As IronPdf.PdfDocument = pdfProcessor.MergePdfDocuments(pdfDocumentList)
	End Sub
End Class

In this example, assembly A's PdfProcessor class uses IronPDF to encapsulate the PDF processing code. Because the methods are designated as internal, they can only be accessed by other internal members of the same assembly. Assembly B's MainClass may easily make use of these internal functions. To know more about the IronPDF code, refer to the IronPDF HTML to PDF Example.

Conclusion

Finally, the C# internal modifier provides strong control over which types and members are visible inside an assembly. It helps create safe, modular, and maintainable applications when used in conjunction with IronPDF. You may strike a compromise between abstraction, security, and usability by enclosing IronPDF-related code inside internal classes or methods. When working with libraries like IronPDF that manage essential functions like PDF document processing, it is especially important to embrace the concepts of encapsulation and limited access to promote a stable and scalable architecture in your C# applications.

A very robust license, redesign options, and a longer duration of programming support are all included in IronPDF's $749 light bundle. Clients can test the item in real application settings during the watermarked testing period. Learn more about IronPDF Licensing to understand the benefits, approval process, and draft form. Check out the Iron Software Website to learn more.