---
title: "More on Xamarin Studio add-ins"
date: 2016-07-27
description: ""
---


As a follow up to my previous post about [creating an add-in for Xamarin Studio](/blogs/creating-an-add-in-for-xamarin-studio/) I thought I'd go into the details of the project template XML.

When creating an add-in that adds a new project type you define each project as a `Project` node inside the `xpt.xml` file. This project node has some attributes, and sub nodes made up of options, references, files and packages.

Think of this post as a sort of API reference for these based on what I've discovered, or been taught. Once again this post would not be possible without the help of [Mikayla Hutchinson](https://twitter.com/mjhutchinson) - she is awesome.

### Variables

In this file you can use `${ProjectName}` to refer to the name of the solution. This is not the file name, just the solution name, so `MySolution.sln` would be called `MySolution` and every instance of `${ProjectName}` would be replaced with `MySolution`.

### The `Project` node

```
<Project name = "${ProjectName}.Core" directory = "./${ProjectName}.Core" type="C#PortableLibrary">
```

The `name` is the name of the `.csproj` file. In the files for this project the `${ProjectName}` is set to this name.

The `directory` is the subdirectory under the solution where this project is created.

The `type` is the type of the project.  The 3 types I know about are:

* `C#PortableLibrary` - PCL
* `MonoDroid` - Android app
* `XamarinIOS` - iOS app

##### The `Options` node

This is a sub-node of `Project`, and is used to set options on the project file. The attributes I am aware of are:

###### PCL projects:
```
<Options Target="Library" TargetProfile = "Profile259"/>
```

* `Target="Library"` - sets this project as a library
* `TargetProfile="Profile259"` - sets the target profile

###### Android projects:
```
<Options AndroidApplication="true" AndroidResgenFile="Resources\Resource.Designer.cs" GenerateSerializationAssemblies="Off" ProductVersion="8.0.30703" SchemaVersion="2.0" AppDesignerFolder="Properties" FileAlignment="512" JavaMaximumHeapSize="1G"/>
```

* `AndroidApplication="true"` - Marks this project as an Android app
* `AndroidResgenFile="Resources\Resource.Designer.cs"` - Tells the Android app which file is autogenerated from the resources
* `JavaMaximumHeapSize="1G"` - Sets the Java heap size, 1G is better than the default 512M

Not sure exactly what the other attributes do - if you know please tell me and I'll update this.

###### iOS projects:

```
<Options />
```

I don't know any of the options here, again if you know please tell me!

##### The `References` node

This is where you define references to libraries or other projects. No need to add references to libraries that come from NuGet here, as these are set via the `Packages` node.

```
<References>
   <Reference type="Package" refto="Mono.Android.Export" />
   <Reference type="Project" refto="${ProjectName}.Core" />
</References>
```

* `type` - `Package` for an assembly either from the .Net framework or from a library that you are shipping, `Project` for a reference to another project in your solution
* `refto` - the assembly to reference (for framework assemblies), or the project name for other projects in the solution.
* `HintPath="xxx"` - specifies the hint path for references to libraries outside of the framework (such as one you are shipping with the add-in)

##### The `Files` node

This is where you define the actual files to copy to your project. These files must come from somewhere, so you need to add them to your project with `Copy to output directory` ticked. You also need to add these files to your `Manifest.addin.xml` file as `Import` entries in the `Runtime` node.

```
<Files>
   <File name="Properties/AndroidManifest.xml" src="Droid/Properties/AndroidManifest.xml"/>
   <RawFile name="Resources/drawable/icon.png" src="Droid/Resources/drawable/icon.png"/>
  
  <File name="Pages/FirstPage.xaml" BuildAction="EmbeddedResource" src="Core/Pages/FirstPage.xaml"/>
  <File name="Pages/FirstPage.xaml.cs" AddStandardHeader="True" src="Core/Pages/FirstPage.xaml.cs" DependsOn="FirstPage.xaml" />  
			
</Files>
```

There are two possible nodes here, `File` and `RawFile`. Use `File` for text files as this will do file ending/unicode conversion. Use `RawFile` for binary files, such as images or libraries to avoid any conversion.

* `name` - the file name including the directory for the file to write to
* `src` - the file name and path of the source file inside your bundle
* `BuildAction` - the build action for this file. For normal compile you don't need this but for Xamarin.Forms `Xaml` files you need to set this to `EmbeddedResource `.
* `AddStandardHeader="True"` - don't know what this does, but is used for xaml files for forms.
* `DependsOn` - sets the file that this depends on, so used for specifying the `Xaml` file for a `xaml.cs` code behind file.
##### The `Packages` node

Here you can define what NuGet packages to install in your app. These are installed as if you installed them manually, so all dependent packages are installed.

```
<Packages>
   <Package Id="Xamarin.Forms" Version="2.3.0.107"/>
   <Package id="MvvmCross" version="4.2.2"/>
   <Package id="MvvmCross.Forms.Presenter" version="4.1.4"/>
</Packages>
```

* `id` - The Id of the NuGet package to install
* `version` - The specific version to install if needed

<hr>

This doc is nowhere near complete, so if you know of other things to add please let me know and I'll update it.