Windowfrompoint solution or alternative

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VB

<DllImport("user32.dll")>
    Public Function WindowFromPoint(ByVal point As Point) As IntPtr
    End Function

I am hoping somebody has a method of getting the windowfrompoint api to work in both 32 bit and 64 bit systems. If that is not possible, is there another api or method to get the window under the mouse cursor?

This is from the pinvoke.net site:

C#

- IntPtr WindowFromPoint(POINT Point) always return 0 in both 32/64 bit process.
- IntPtr WindowFromPoint(int x, int y) works in 32-bit but fails in 64-bit process.

The import statement at the top of this question works for me on a 64 bit system, but not on 32 bit

Posted 12-Oct-14 21:37pm

Craig Haywood

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BillWoodruff 13-Oct-14 5:31am

In .NET 4.0 and later:

bool is64BitOS = Environment.Is64BitOperatingSystem;

http://msdn.microsoft.com/en-us/library/system.environment.is64bitoperatingsystem.aspx

See Raymond Chen's article for the sordid history of MS' API calls to get OS bit-depth:

http://blogs.msdn.com/b/oldnewthing/archive/2010/12/30/10110077.aspx

Craig Haywood 13-Oct-14 6:30am

Thanks BillWoodruff.

I always used
If IntPtr.Size = 8 Then

2 solutions

Solution 1

Read these:
https://sites.google.com/site/x64lab/home/notes-on-x64-windows-gui-programming/windowfrompoint-on-x64-vista[^]

http://stackoverflow.com/questions/12949753/windowfrompoint-doesnt-work-correctly-on-64bit-net-framework[^]

Re-Active Disabled Controls[^]

Posted 12-Oct-14 22:03pm

Mehdi Gholam

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Craig Haywood 13-Oct-14 4:28am

Hi Mehdi,

This does not provide a solution. The first link takes me to an incomprehensible solution as I don't even know what language that is. The second link is just the msdn explanation of what the function does and the third uses the exact same declare statement I am using

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Pikoh · Accepted Answer · 2014-10-12T22:13:00

Solution 2

I've never used WindowFromPoint,but seeing that one signature works in x32 and the other in x64,what i would do is check if my program is running in a 32 or 64 bits OS and call one or the other. To check what type of OS it's running you may check this(StackOverflow)[^]

Posted 12-Oct-14 22:13pm

Pikoh

Comments

Craig Haywood 13-Oct-14 4:30am

Where have you found that different signatures works on different bit systems? Can you give an example

Pikoh 13-Oct-14 4:39am

You have stated that:

- IntPtr WindowFromPoint(int x, int y) works in 32-bit but fails in 64-bit process.

So try using WindowFromPoint(int x, int y) in 32 bits OS and WindowFromPoint(POINT Point) in 64 bits OS

Craig Haywood 13-Oct-14 4:53am

Indeed I did, but how do you declare the same function twice in the same application?

Pikoh 13-Oct-14 4:56am

They have different signature,so you can just add this

[DllImport("user32.dll")]
static extern IntPtr WindowFromPoint(Point Point);
[DllImport("user32.dll")]
static extern IntPtr WindowFromPoint(int xPoint, int yPoint);

to your app,check what bit OS is it running, and call the method acordingly

Craig Haywood 13-Oct-14 5:10am

I never knew you could dllimport a function with the same name twice if it has different signitures. Thanks Pikoh, I am going to accept your solution as it seems to be working in initial tests

Pikoh 13-Oct-14 5:25am

You're welcome :)