Getting Started – Cross Platform HMI

If you do not have a copy of Visual Studio you can download a free version of Visual Studio Community (formerly Visual Basic Express or C# Express) from  You can choose whether to use Visual Basic or C#, but if you have no experience with either language, Visual Basic is easier for new developers.  We do recommend Visual Studio 2017 or higher.

There are many Cross Platform GUI tools available.  We have chosen Avalonia because of its popularity.  Here’s a link detailing how to create an Avalonia project:  We recommend downloading and using the extension:

Working Avalonia Solution

You should have a running Avalonia application at this point

Adding OASAvalonia to Existing Avalonia Solution

Step 1 – Add the OASAvalonia library

Right-Click on Dependencies in the Solution Explorer

Click the “Browse” button at the bottom

Navigate to C:\Program Files (x86)\Open Automation Software\OPC Systems.NET\.

Click “OK” button

Step 2 – Add Namespace

Edit the Mainwindow.xaml file

Add xmlns:b=”clr-namespace:OASAvalonia;assembly=OASAvalonia” to the xml namespaces

Step 2 – Add OAS_Controls

Type “<OAS_” and you will a list of  OAS enhanced controls

Choose one and add an OAS properties – below are the properties for  OAS_TextBox:

<b:OAS_TextBox Grid.Row=”0″ Grid.Column=”2″ Name=”OAS_TextBox” Width=”70″ Height=”26″ Text_TagName=”OASAvalonia.Text_TagName.Value”
IsVisible_TagName=”OASAvalonia.IsVisible_TagName.Value” IsVisible_Inverse=”False” IsVisible_BadQualityTrue=”True” IsVisible_Inverse_Link=”PCB_IsVisible_Inverse” IsVisible_BadQualityTrue_Link=”PCB_IsVisible_BadQualityTrue”
IsEnabled_TagName=”OASAvalonia.IsEnabled_TagName.Value” IsEnabled_Inverse=”False” IsEnabled_BadQualityTrue=”True” IsEnabled_Inverse_Link=”PCB_IsEnabled_Inverse” IsEnabled_BadQualityTrue_Link=”PCB_IsEnabled_BadQualityTrue”
Foreground_TagName=”OASAvalonia.Foreground_TagName.Value” Foreground_True=”Blue” Foreground_False=”RosyBrown” Foreground_BadQualityColor=”White” Foreground_True_Link=”OAS_TextBox_ComboBox_ForegroundTrue” Foreground_False_Link=”OAS_TextBox_ComboBox_ForegroundFalse”
Background_TagName=”OASAvalonia.Background_TagName.Value” Background_True=”White” Background_False=”Green” Background_BadQualityColor=”Red” Background_True_Link=”OAS_TextBox_ComboBox_BackgroundTrue” Background_False_Link=”OAS_TextBox_ComboBox_BackgroundFalse”

OAS Avalonia Visual Studio Solution

We have also provided an example OAS Avalonia solution

Step 1

Load the DemoTags  Tag configuration, the default path is C:\Program Files (x86)\Open Automation Software\OPC Systems.NET\DemoFiles\DemoTags.Tags.

Step 2

Start Visual Studio and select File->Open->Project/Solution : OASCrossPlatformHMIDemoApplication

Step 3

Run Application