Project class

The currently-loaded project. Reached through Host.CurrentProject; the IDE swaps the underlying instance when the user switches projects, but the Project reference held by the addin remains a stable handle that always reflects the currently loaded project’s state.

The class groups four kinds of capability:

Identification — Name, Path, BaseFolderPath, ProjectID, version + architecture + build-output info.
Lifecycle commands — Save, Close, Build, Clean (the same actions the IDE’s File menu exposes).
Programmatic access — Evaluate runs an arbitrary expression against the running project context (the same engine as the DEBUG CONSOLE); RootFolder is the entry into the virtual file system.
Persistent storage — LoadMetaData / SaveMetaData store per-addin key/value pairs inside the .twinproj file.

With Host.CurrentProject
    Host.DebugConsole.PrintText "Project: " & .Name & " (" & .Path & ")"
    Host.DebugConsole.PrintText "Version: " & .VersionMajor & "." & .VersionMinor & "." & _
                                              .VersionBuild & "." & .VersionRevision
    Host.DebugConsole.PrintText "BuildType: " & .BuildType
End With

Properties
Methods
VbBuildType

Properties

Architecture

The project’s target processor architecture. As VbArchitecture (vbX86 / vbX64 / vbARM …). Read-only.

BaseFolderPath

The folder containing the project’s .twinproj file — i.e. the directory part of Path. String, read-only.

BuildFileExtension

The file extension the build output will carry ("exe", "dll", "ocx", "twinpack"). String, read-only. Implied by BuildType.

BuildOutputPath

The full path of the project’s build output, including filename and extension — the file that Build writes (or would write) to. String, read-only.

BuildType

The kind of artefact the project builds. As VbBuildType (see below). Read-only.

Name

The project’s display name, as configured in its Settings. String, read-only.

Path

The full path to the project’s .twinproj file. String, read-only.

ProjectID

The project’s GUID as a string — e.g. "{99DEC38C-75F6-4488-8EE7-2D52D83881D2}". String, read-only. Stable across renames; useful as a key in addin-side per-project state.

RootFolder

The root of the project’s virtual file system — the entry point for walking sources, resources, packages, and other project contents. As Folder. Read-only.

VersionBuild, VersionMajor, VersionMinor, VersionRevision

The four components of the project’s current version (Major.Minor.Build.Revision). Long, read-only.

Methods

Build

Builds the project. Equivalent to the IDE’s File → Make/Build… command. Writes the output to BuildOutputPath; errors raised during compilation surface in the DEBUG CONSOLE the same way they would for a user-initiated build.

Syntax: project.Build

Clean

Deregisters and deletes any built executables relating to the project — the inverse of a previous Build.

Syntax: project.Clean

Close

Closes the project. Equivalent to File → Close Project. If the project is dirty the IDE may prompt the user before actually closing.

Syntax: project.Close

Evaluate

Evaluates an expression in the context of the currently-loaded project, as if the user had typed it into the DEBUG CONSOLE. Returns the expression’s value as a Variant (anything from a Long to a serialised object, depending on what was evaluated).

Syntax: project.Evaluate( EvalString [, Options ] ) As Variant

EvalString: required The expression to evaluate. String. Any expression valid in the DEBUG CONSOLE works — arithmetic (10.5 * 4), property reads (MyForm.Caption), function calls (MyModule.MyFunc(42)), and so on.
Options: optional A DebuggerEvaluateOptions value. Default NONE.

On Error Resume Next
Dim result As Variant = Host.CurrentProject.Evaluate("10.5 * 4")
If Err.Number = 0 Then
    Host.ShowMessageBox CStr(result), "OK", "Result"
Else
    Host.ShowMessageBox "ERROR " & Err.Number & vbCrLf & vbCrLf & Err.Description, "OK", "ERROR"
End If

Same engine the DEBUG CONSOLE uses, so the same set of identifiers, the same accessibility rules, and the same error semantics apply — including the run-time errors that surface from inside the evaluated expression. Wrap in On Error Resume Next if the expression may raise.

LoadMetaData

Reads a previously-stored value out of the project’s meta-data area inside the .twinproj file.

Syntax: project.LoadMetaData( Key ) As String

Key: required The meta-data key. String. Returns "" if no value has been stored under Key.

The meta-data is associated with the loaded project, not with the addin globally. Closing the project closes the storage too; opening a different project gives a different store. For addin-wide persistence (e.g. addin-level options that should follow the user across projects), use GetSetting / SaveSetting against the registry — sample 15 demonstrates that pattern.

Save

Saves the project. Equivalent to File → Save Project.

Syntax: project.Save

SaveMetaData

Stores a string value under a key inside the project’s meta-data area in the .twinproj file. The value persists across project re-opens.

Syntax: project.SaveMetaData Key, Value

Key: required The meta-data key. String.
Value: required The value to store. String.

' Persist a user-selected option that should follow the project:
Host.CurrentProject.SaveMetaData "MyAddIn.LastUsedFilter", "*.bas"

' Restore it next time the project loads:
Private Sub Host_OnProjectLoaded()
    Dim lastFilter As String = Host.CurrentProject.LoadMetaData("MyAddIn.LastUsedFilter")
    If Len(lastFilter) = 0 Then lastFilter = "*.twin"
    ' …
End Sub

VbBuildType

The artefact-kind enum returned by BuildType. Declared inline on the Project interface.

Constant	Value	Description
StandardEXE	0	A standard Win32 executable.
StandardDLL	1	A standard Win32 DLL. Addins themselves are Standard DLL projects.
ActiveXDLL	2	A COM (ActiveX) DLL.
ActiveXControl	3	A COM (ActiveX) control — `.ocx`.
PackageTWINPACK	4	A twinBASIC package (`.twinpack`).