> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/xamarin/learn-more/type-converter.md).

# Type Conversion

Learn how to use Apryse type conversion for calling C functions from C# in Xamarin SDK. Manage types and binding types efficiently with PInvoke. Explore key concepts and conversion examples. The Aprys

Apryse type conversion allows you to call C functions directly from C#.

{% tabs %}
{% tab title="Android" %}

## Managed type and binding types

Apryse for Xamarin SDK takes advantage of PInvoke which allows calling C functions from C# directly. This applies to all core classes that are shared between Xamarin.Android and Xamarin.iOS. However, the `PDFViewCtrl` class and PDFViewCtrlTools library are direct Xamarin bindings from the source code. This article will walk you through how to deal with managed type and binding types.

Key concepts:

* All managed types are in `pdftron` namespace
* All binding types are in `pdftronprivate` namespace

A [`TypeConvertHelper`](https://sdk.apryse.com/api/xamarinandroid/pdfnet/api/pdftron.PDF.TypeConvertHelper.html) class is provided to convert between managed types and binding types. For example:

### PDFDoc

From `pdftronprivate.PDF.PDFDoc` to `pdftron.PDF.PDFDoc`:

{% code lineNumbers="true" %}

```csharp
var pdfDoc = TypeConvertHelper.ConvPdfDocToManaged(privatePdfDoc);
```

{% endcode %}

From `pdftron.PDF.PDFDoc` to `pdftronprivate.PDF.PDFDoc`:

{% code lineNumbers="true" %}

```csharp
var privatePdfDoc = TypeConvertHelper.ConvPDFDocToNative(pdfDoc);
```

{% endcode %}

### Annot

From `pdftronprivate.PDF.Annot` to `pdftron.PDF.Annot`:

{% code lineNumbers="true" %}

```csharp
var annot = TypeConvertHelper.ConvAnnotToManaged(privateAnnot);
```

{% endcode %}

From `pdftron.PDF.Annot` to `pdftronprivate.PDF.Annot`:

{% code lineNumbers="true" %}

```csharp
var privateAnnot = TypeConvertHelper.ConvAnnotToNative(annot);
```

{% endcode %}
{% endtab %}

{% tab title="iOS" %}

## Managed type and binding types

Apryse for Xamarin SDK takes advantage of PInvoke which allows calling C functions from C# directly. This applies to all core classes that are shared between Xamarin.Android and Xamarin.iOS. However, the `PDFViewCtrl` class and PDFViewCtrlTools library are direct Xamarin bindings from the source code. This article will walk you through how to deal with managed type and binding types.

Key concepts:

* All managed types are in `pdftron` namespace
* All binding types are in `pdftronprivate` namespace

A [`TypeConvertHelper`](https://sdk.apryse.com/api/xamarinios/pdfnet/api/pdftron.PDF.TypeConvertHelper.html) class is provided to convert between managed types and binding types. For example:

### PDFDoc

From `pdftronprivate.PTPDFDoc` to `pdftron.PDF.PDFDoc`:

{% code lineNumbers="true" %}

```csharp
var pdfDoc = TypeConvertHelper.ConvPdfDocToManaged(privatePdfDoc);
```

{% endcode %}

From `pdftron.PDF.PDFDoc` to `pdftronprivate.PTPDFDoc`:

{% code lineNumbers="true" %}

```csharp
var privatePdfDoc = TypeConvertHelper.ConvPDFDocToNative(pdfDoc);
```

{% endcode %}

### Annot

From `pdftronprivate.PTAnnot` to `pdftron.PDF.Annot`:

{% code lineNumbers="true" %}

```csharp
var annot = TypeConvertHelper.ConvAnnotToManaged(privateAnnot);
```

{% endcode %}

From `pdftron.PDF.Annot` to `pdftronprivate.PTAnnot`:

{% code lineNumbers="true" %}

```csharp
var privateAnnot = TypeConvertHelper.ConvAnnotToNative(annot);
```

{% endcode %}
{% endtab %}
{% endtabs %}


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