dotnet/Documentation/compatibility/vb_net-no-longer-supports-partial-namespace-qualification-for-system_windows-apis.md

VB.NET no longer supports partial namespace qualification for System.Windows APIs

Scope

Minor

Version Introduced

4.5.2

Source Analyzer Status

Available

Change Description

Beginning in .NET 4.5.2, VB.NET projects cannot specify System.Windows APIs with partially-qualified namespaces. For example, referring to Windows.Forms.DialogResult will fail. Instead, code must refer to the fully qualified name (System.Windows.Forms.DialogResult) or import the specific namespace and refer simply to DialogResult.

• Quirked
• Build-time break

Recommended Action

Code should be updated to refer to System.Windows APIs either with simple names (and importing the relevant namespace) or with fully qualified names.

Affected APIs

• Not detectable via API analysis

Category

Visual Basic .NET

More information