7. FAQ and troubleshooting #

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Installation and startup #

The component stays gray or empty #

"UI thread blocked": the most common pitfall #

Webview initialization is asynchronous: it needs the Windows message loop to run. A long PowerScript loop executed in the window open, before giving control back, prevents the component from finishing its load.

// AVOID: the component stays gray for the whole processing
uo_grid.of_add_column("nom", "Name", 200)
of_charger_50000_lignes()      // 8 seconds without giving control back

// PREFER: let the window display itself, THEN load
this.PostEvent("ue_charger")

The component loses its theme / turns light again after a while #

You have most likely reused an instance without resetting it, or set a local theme that was never cleared. Call of_reset() before displaying different content, and set the theme globally with PBT_SetDefaultTheme rather than component by component (Themes).

Runtime behavior #

The properties I set in the constructor seem to be ignored #

They are not: commands issued before ue_ready are queued and replayed in order. If the display does not match, it is almost always because a later command overwrites the first one — or because the component was never reset between two uses.

A "leftover" from the previous display remains #

Cause number one of visual glitches: of_reset() was not called. Reusing an instance to display something else keeps everything that was set before (colors, mode, automatic height, items). Make sure of_reset() really is called before concluding that it is broken.

Reading a property back does not reflect what the user is doing #

First check whether an event announces that change: when one exists, it refreshes the property on the way and reading back gives the real state (is_address follows the link the user clicks, is_text follows their typing). Otherwise, reading returns the last value set from PowerBuilder (the PB cache) — and the event, with its value as a parameter, is then the only channel (Shared foundation).

An event never fires #

• Ambient mouse events (ue_mouse_enter, ue_mouse_leave, ue_rclicked): they are opt-in, set ib_track_mouse = true. They are also only published by the components where they make sense.
• ue_auto_height / ue_auto_width: opt-in as well (ib_auto_height, ib_auto_width), published by a specific list of components. Exception: on ribbon and toolbar, ue_auto_height is always active (intrinsic height, no property to set).
• Event scripted in the wrong place: script it on the control placed in the window, or on a userobject inherited from the component — not on u_pbt_base.

A menu or a tooltip stays on screen #

Menus and tooltips are real system windows: they close when you click elsewhere, on Esc, and when the application loses the foreground, and a tooltip fades away after 10 seconds at the latest. One remaining case: destroying the component while one of its menus is open — close it first.

No tooltip appears at all #

This is intentional: tooltips do not appear when your application does not have the focus. Click inside the window first.

Images and icons #

An image does not appear #

• The path must be reachable on the machine running the application (preferably an absolute path, or one relative to the working folder).
• Formats: PNG, JPG, GIF, BMP, ICO, SVG, WEBP. An image that cannot be found is simply hidden, without blocking the component.
• DLL resource: the syntax is full_path.dll:RESOURCE_NAME (a resource name, not a file name).

A mono: icon appears empty or distorted #

A mono: icon is a mask: it has no natural size. If the component does not size it (a rare case, outside the standard components), give it an explicit size — for example [picture=mono:img\ok.svg,16,16] in rich text.

I replaced an image on disk and the old one is still displayed #

Images are cached for 5 minutes to avoid flicker when re-rendering. For an image changed on the fly, add a varying suffix to the path (img\logo.png?v=2).

Performance #

The first component is slow to appear #

That is the Edge process starting up, paid only once. Call PBT_Warmup() when the application starts: the cost is absorbed while the rest loads (Installation).

The display flickers while I build my content #

Wrap the construction:

uo_grid.of_set_redraw(false)
… additions and assignments …
uo_grid.of_set_redraw(true)

Feeding a component from a DataStore is slow #

The transfer itself is linear and fast. The dominant cost lies upstream: your Retrieve() or your data generation in PowerScript. For large volumes generated in code, fill the DataStore in blocks — concatenating a string of several megabytes is quadratic in PowerScript.

Living alongside PowerBuilder #

A hosted PowerBuilder control is drawn over everything #

That is the expected behavior: a hosted control (tab page, dockable panel) is a native window, painted above the web layer. In return, your DataWindows stay crisp and fast. No web effect can be drawn over it.

The component turns white when I am stopped in the debugger #

Structural WebView2 behavior: the UI thread is frozen by the debugger, so the webview can no longer present itself. The compiled application is not affected. Resume execution and the display comes back.

Are there msedgewebview2 processes leaking? #

No: each component releases its webview when it is destroyed, handled by the userobject destructor in the normal window closing flow.

Accented characters display incorrectly #

Pass your labels as plain text from PowerBuilder (standard PB strings). For characters not on the keyboard, use Char() — for example Char(8364) for the euro sign — rather than a code page byte.

Miscellaneous #

A file export fails #

The returning event (ue_file_saved, ue_xlsx_saved…) carries ab_ok = false and a message. Common causes: a folder that is not writable (Program Files), a file already open in another application. Write to a user folder (%TEMP%, %LOCALAPPDATA%).

The "DEMO" badge appears #

The license is not active in this context — see License and demo mode.

Return codes of the of_* methods #

Details of the last failure: of_get_last_error().

Asking for help #

Include in your request:

• your PowerBuilder version and bitness (32 / 64);
• your Windows version;
• the library version (PBT_GetVersion) and the WebView2 runtime version (PBT_CheckRuntime);
• the license state (PBT_LicenseStatus);
• a minimal code snippet that reproduces the case.

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