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When we last left the dictionary project, we were able to display the dictionary entries but hadn't yet gotten around to searching it. Today, we'll place the lookup control, though we won't hook it up until next time. First, we give the edit control an ID and create some member variables to keep track of it. class RootWindow : public Window { ...

This is basically the same thing as The dangers of playing focus games when handling a WM_KILLFOCUS message, just with activation in place of focus. One developer discovered the hard way that if you mess with activation inside your WM_ACTIVATE handler, things get weird. The author noted that if he posted a message and did the work from the posted...

I had noted last year that WM_KILLFOCUS is the wrong time to do field validation. Here's another example of how messing with the focus during a WM_KILLFOCUS message can create confusion. Consider an edit control that displays feedback via a balloon tip. For example, password edit controls often warn you if you're typing your password while Caps...

If you ever tried to build a custom animated logo for Internet Explorer, you cetainly noticed that the frames of the animation are arranged vertically rather than horizontally. Why is that? Because it's much more efficient. Recall that bitmaps are stored as a series of rows of pixels. In other words, if you number the pixels of a bitmap like ...

A subtlety that adds a level of polish to your dialogs is supporting double-clicked radio buttons as an abbreviation for "select + OK". (Or "select + Next" or "select + Finish" if the page is part of a wizard.) Consider the following dialog template and associated dialog procedure: 1 DIALOGEX DISCARDABLE 32, 32, 200, 76 STYLE DS_MODALFRAME | ...

Last time, I left you with a brief puzzle. Here are two approaches. I am not a GDI expert, so there may be even better solutions out there. To emphasize the transparency, I'll change the window background color to the application workspace color. BOOL WinRegisterClass(WNDCLASS *pwc) { pwc->hbrBackground = (HBRUSH)(COLOR_APPWORKSPACE + 1);...

Last time, we saw how to draw themed and unthemed radio buttons, and I mentioned that menu glyphs are trickier. They're trickier because they are provided as raw monochrome bitmaps instead of fully-formed color-coordinated bitmaps. First, let's do it wrong in order to see what we get. Then we'll try to fix it. Start with a clean new scratch prog...

The DrawFrameControl function allows you to render standard Windows elements in your custom controls. Let's start by simply rendering a selected radio button. Start with our new scratch program and make this very simple change: class RootWindow : public Window { ... protected: void PaintContent(PAINTSTRUCT *pps); ... }; void RootWindow::Pa...

Last time, I alluded to weirdness that can result in the normal cycle of destruction messages being thrown out of kilter. Commenter Adrian noted that the WM_GETMINMAXINFO message arrives before WM_NCCREATE for top-level windows. This is indeed unfortunate but (mistake or not) it's been that way for over a decade and changing it now would intro...

There are two window messages closely-associated with window destruction, the WM_DESTROY message and the WM_NCDESTROY message. What's the difference? The difference is that the WM_DESTROY message is sent at the start of the window destruction sequence, whereas the WM_NCDESTROY message is sent at the end. This is an important distinction when y...