CefEnvironmentOptions class

Carries the host’s pre-creation configuration for the CEF environment — runtime folder, user-data folder, and the optional debug-log destination. Surfaces on every CefBrowser control as its EnvironmentOptions property; the control instantiates one automatically before raising the Create event.

The fields below take effect only while the CEF runtime is being launched — that is, before or during the control’s Create event. Assigning them after that point has no effect on the live environment.

Private Sub CefBrowser1_Create()
    CefBrowser1.EnvironmentOptions.UserDataFolder = _
        Environ$("APPDATA") & "\MyApp\CEF\"
    CefBrowser1.EnvironmentOptions.LogFilePath = _
        Environ$("APPDATA") & "\MyApp\CEF\debug.log"
    CefBrowser1.EnvironmentOptions.LogSeverity = CefLogWarning
End Sub

The type itself is Private Class — you reach instances only through the control’s EnvironmentOptions property and cannot declare a variable typed as CefEnvironmentOptions from outside the package.

Properties

BrowserExecutableFolder

Path to the folder containing libcef.dll and its accompanying runtime files. String. Default: empty (the runtime is loaded from %LocalAppData%\twinBASIC_CEF_Runtime\<version-stamped-folder> — see Installing runtime files).

Set this to point at a portable side-by-side deployment, e.g. a CEF folder shipped beside the application executable:

Private Sub CefBrowser1_Create()
    CefBrowser1.EnvironmentOptions.BrowserExecutableFolder = _
        App.Path & "\cef145_win64"
End Sub

If libcef.dll is not found at the configured (or default) location, the Error event fires with the exact path that was searched.

LogFilePath

Path to a writable file CEF will append its debug log to. String. Default: empty (no log file is written, regardless of LogSeverity).

Used together with LogSeverity — messages at or above the chosen severity are written to this file. The log is appended across runs; rotate or delete the file as needed.

LogSeverity

The minimum severity at which CEF records messages to the log file named by LogFilePath. CefLogSeverity. Default: CefLogDisable (logging off).

Set to CefLogWarning or CefLogError when investigating runtime issues, and back to CefLogDisable for normal use.

UserDataFolder

Path to the folder CEF uses for the user profile — cache, cookies, history, local storage, and so on. String. Default: empty (the runtime picks a folder under %LocalAppData%\twinBASIC_CEF\<ProjectName>\).

Set a writable, application-specific path when the default would land in a read-only location, or when multiple deployments of the same application must keep their profiles separate. The same folder cannot be opened by two CEF processes simultaneously — if it’s already locked, the Error event fires with “CEF cache path already locked by another process”.