Compiler Warning WFAC010

Version introduced: .NET 6

Remove high DPI settings from app.manifest and configure via Application.SetHighDpiMode API or ApplicationHighDpiMode project property.

Windows Forms applications should specify application DPI-awareness via the application configuration or with the Application.SetHighDpiMode API.

Important

Starting with .NET 9, this warning has changed to WFO0003.

Workarounds

Using C#

Use the new bootstrap API by calling the ApplicationConfiguration.Initialize method before Application.Run().

class Program
{
    [STAThread]
    static void Main()
    {
        ApplicationConfiguration.Initialize();
        Application.Run(new Form1());
    }
}

The ApplicationConfiguration.Initialize method is generated when your app compiles, based on the settings in the app's project file. For example, look at the following <Application*> settings:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net8.0-windows</TargetFramework>
    <Nullable>enable</Nullable>
    <UseWindowsForms>true</UseWindowsForms>
    <ImplicitUsings>enable</ImplicitUsings>

    <ApplicationVisualStyles>true</ApplicationVisualStyles>
    <ApplicationUseCompatibleTextRendering>false</ApplicationUseCompatibleTextRendering>
    <ApplicationHighDpiMode>SystemAware</ApplicationHighDpiMode>
    <ApplicationDefaultFont>Microsoft Sans Serif, 8.25pt</ApplicationDefaultFont>

  </PropertyGroup>

</Project>

These settings generate the following method:

[CompilerGenerated]
internal static partial class ApplicationConfiguration
{
    public static void Initialize()
    {
        global::System.Windows.Forms.Application.EnableVisualStyles();
        global::System.Windows.Forms.Application.SetCompatibleTextRenderingDefault(false);
        global::System.Windows.Forms.Application.SetHighDpiMode(HighDpiMode.SystemAware);
        global::System.Windows.Forms.Application.SetDefaultFont(new Font(new FontFamily("Microsoft Sans Serif"), 8.25f, (FontStyle)0, (GraphicsUnit)3));
    }
}

Using Visual Basic

Visual Basic operates a little differently than C# at the moment. The project file settings are required for Visual Studio to detect the application settings, but you must also configure the settings in the project's property page Application > Application Framework (which affects the My Project\Application.myapp file) or in the application startup events.

Important

Font isn't settable in the project properties.

The following code example demonstrates handling the ApplyApplicationDefaults event to configure the default font and HighDPI mode:

Imports Microsoft.VisualBasic.ApplicationServices

Namespace My
    Partial Friend Class MyApplication
        Private Sub MyApplication_ApplyApplicationDefaults(sender As Object, e As ApplyApplicationDefaultsEventArgs) Handles Me.ApplyApplicationDefaults
            e.Font = New Font("Microsoft Sans Serif", 8.25)
            e.HighDpiMode = HighDpiMode.SystemAware
        End Sub
    End Class
End Namespace

Manage the warning

Suppress the warning with either of the following methods:

• Set the severity of the rule in the .editorConfig file.

  [*.{cs,vb}]
  dotnet_diagnostic.WFAC010.severity = none
  

  For more information about editor config files, see Configuration files for code analysis rules.

• Add the following PropertyGroup to your project file:

  <PropertyGroup>
      <NoWarn>$(NoWarn);WFAC010</NoWarn>
  </PropertyGroup>
  

• Suppress in code with the #pragma warning disable WFAC010 directive.