Getwindowrect returns wrong dimensions

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Hi there, I am having the big problem with getting the area of hwind with
routine GetWindowRect. Even Spy++ or his implementation returns rectangle, that is smaller than real
area. Its a some special kind of application, I am looking for some alternative to GetWindowRect,
or how can I get all the window area programmatically correct.

What I have tried:

I have tried Spy++, and debug GetWindowRect but it doesn't move me forward.
I need some way figure out how the window sends wrong rectangle, how I can get the right one.

Posted 29-Mar-20 7:03am

lacir

Updated 30-Mar-20 3:21am

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Richard MacCutchan 30-Mar-20 3:47am

Please do not repost the same question. You already asked this in the Managed C++ forum.

2 solutions

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steveb · Answer 1 · 2020-03-30T03:23:00

Solution 2

struct RECT that is returned from GetWindowRect() can also be further manipulated by calling:
GetClientRect()
ScreenToClient()
ClientToScreen()

Yours sound like one of those cases

It would have been helpful if you posted the dimensions of your RECT. If top and left both == 0 then it is Client coordinates and if they are above zero then it is a Screen Coordinates.

You also need to pay attention to your Coordinate Space and Transformation functions:

[^]

Posted 30-Mar-20 3:23am

steveb

Updated 30-Mar-20 3:28am

v2

Comments

lacir 30-Mar-20 9:43am

real dimensions are 600x465
GetClientRect() returns in debugger {LT(0, 0) RB(480, 372) [480 x 372]}
ClientToScreen(hwnd, reinterpret_cast<point*>(&wr.left)); {{LT(72, 0) RB(480, 372) [408 x 372]}}
ClientToScreen(hwnd, reinterpret_cast<point*>(&wr.right)); {LT(72, 0) RB(552, 372) [480 x 372]}
but the area is still smaller 480 x 372 with no regards to ClientToScreen() its given by GetClientRect

Richard MacCutchan 30-Mar-20 9:56am

In your original question you use GetWindowRect, in this one you are using GetClientRect. You need to learn the difference between these two functions.

lacir 30-Mar-20 10:00am

Both returns same 480x372 size, just
GetWindowRect returns without positional shift, coordinates LT differs from 0 {LT(95, 310) RB(575, 682) [480 x 372]}

Richard MacCutchan 30-Mar-20 10:08am

Whatever you are doing there is something wrong with your code. If either of these methods returned the wrong values then more than 90% of all Windows applications would stop working.

Richard MacCutchan 30-Mar-20 10:10am

I have a strong suspicion that you are getting the wrong Window handle.

steveb 30-Mar-20 10:02am

Double check you CreateWindow() functions. Windows has a tree-like composition, i.e. it is possible to create nested windows within parent window by calling CreateWindow() with the parent window handle. If this is the case your Spy may have focus on a different window. Examine the Tree in your Spy app

lacir 30-Mar-20 10:12am

Ok I checked with Spy++ visual studio, it has correct size, the problem is with GetClientRect(), before I was using Spy++ implementation from this site and it shows incorrectly.

steveb 30-Mar-20 10:26am

Can you check the source code?

KarstenK · Answer 2 · 2020-03-29T07:11:00

Solution 1

I guess that you have some flaw in your code or logic. Read the GetWindowRect documentation and try the sample code. Maybe your problem is about understanding some non client area.

Be sure that you call with correct parameter, especially the window handle.

Posted 29-Mar-20 7:11am

KarstenK

Comments

KarstenK 30-Mar-20 5:16am

Paint your window with some color to see the difference. Than check out the different area. Find your bug ;-)