Passing variables with PostMessage

[thebarslider]

I am trying to pass a double variable to a function in my main thread by using PostMessage.

My code is as follows:

AfxGetMainWnd()->PostMessage(MY_WM_MESSAGE_FREQUENCY,m_RecordingProgrammeFrequency,0);

This works fine an executes the following function:

LRESULT COneDlg::OnUpdateFrequency(WPARAM RecordFrequency, LPARAM lParam)

{
m_pWinTV->SetFrequency(RecordFrequency);
return (LRESULT) 1;
}

The problem i am having is that the computer cuts off my double.

For example: 95.95 becomes 95

My first thoughts are that i should pass a pointer to the double instead but am having problems doing this too.

Does anyone have any suggestions?

Mark.

 

[palbano]

Use the LPARAM argument of PostMessage rather than the WPARAM, it's a larger storage type than the WPARAM and the double type will fit.

-pete

 

[thebarslider]

Dear All,

I have tried the suggestion from pete but the LPARAM is still a long integer and won't take my double (floating point number)

 

[apatterno]

The problem is the implicit conversion from double to WPARAM or LPARAM (they are both 32-bit numbers).

You could try this,

double d = 95.95
long *pl = (long*)&d;
wnd.SendMessage(pl[0],pl[1]);

Note that this gets very messy and for sure isn't portable.

 

[palbano]

>> Use the LPARAM argument of PostMessage rather than the
>> WPARAM, it's a larger storage type than the WPARAM and
>> the double type will fit.

NO, that will not work! double is a "complex" type and therefore cannot simply be cast to simple types!

What BONEHEAD told you that? oh... right... it was me...

LOL
Seriously though, i am sorry for wasting your time with a hasty response that i didn't even spend time thinking about. I will try to do better in the future.

-pete