> 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/guides/tools/annotation-default-properties.md).

# Setting default annotation properties in Xamarin viewer

Learn how to set default properties for annotations in Xamarin.iOS. Discover how to customize stroke color, fill color, opacity, and more. Optimize your app with PTColorDefaults. The Apryse Xamarin SD

{% hint style="info" %}
**This tutorial only applies to Xamarin.iOS. See Xamarin.Android equivalent here .**
{% endhint %}

When creating a new annotation, the initial properties (such as line thickness, fill colour, opacity, etc.) are set to the last value that the user selected for an annotation of that type. For example, if the user changes an ellipse annotation's stroke color from green to red, the next ellipse annotation that the user creates would have a stroke color of red. These default colors are saved in the app's [user default dictionary](https://developer.apple.com/foundation/userdefaults/1416603-standard/).

The tools read and write values via the `Tools package`[`PTColorDefaults`](https://sdk.apryse.com/api/xamarinios/tools/api/pdftron.PDF.Tools.PTColorDefaults.html) type (class) interface.

### Examples

Sets the default stroke color for rectangle annotations.

{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}

```csharp
ColorDefaults.SetDefaultColor(UIColor.Green, PTAnnotType.e_ptSquare, "Color", ColorPostProcessMode.e_postprocess_none);
```

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

Available properties:

| Property name    | Key               |
| ---------------- | ----------------- |
| Stroke color     | "Color"           |
| Fill color       | "FillColor"       |
| Opacity          | "Opacity"         |
| Border thickness | "BorderThickness" |
| Free text size   | "FreeTextSize"    |

Reads the default fill color for ellipse annotations.

{% tabs %}
{% tab title="C#" %}
{% code lineNumbers="true" %}

```csharp
var fillColor = PTColorDefaults.GetDefaultColorForAnnotType(PTAnnotType.e_ptCircle, "FillColor", ColorPostProcessMode.e_postprocess_none);
```

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


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