1. SendMessage Returns a Value?
I've looked up SendMessage info at msdn, but can't find return values
for success/fail. Does anybody know how to determine if the message was
sent or received properly?
Here's the snippet of code I'm using...
-- call AddFontResource
if AddFontResource != -1 then
junk = allocate_string( "free000.ttf" )
if xSendMessage!= -1 then
fonter = c_func( AddFontResource, { junk } )
if fonter != 0 then
junk = c_func(xSendMessage,{HWND_BROADCAST,
WM_FONTCHANGE, 0, 0})
-- RIGHT HERE... HOW DO I DETERMINE IF xSendMessage completed properly?
didAddFontResource = (1=1)
else
errMsg = "AddFontResource failed."
end if
else
errMsg = "Could not access SendMessage."
end if
free(junk)
else
errMsg = "Could not access AddFontResource."
end if
2. Re: SendMessage Returns a Value?
From the SDK: The return value specifies the result of the message
processing; it depends on the message sent.
It appears that a WM_FONTCHANGE message will return 0. Maybe
SendMessage will return 0 for any message unless you specify a different
value?
i.e.
if uMsg = WM_FONTCHANGE then
return 100
end if
will return 100 as a result
whereas
if uMsg = WM_FONTCHANGE then
end if
returns 0
C. K. Lester wrote:
>
> I've looked up SendMessage info at msdn, but can't find return values
> for success/fail. Does anybody know how to determine if the message
> was sent or received properly?
>
> Here's the snippet of code I'm using...
>
> -- call AddFontResource
> if AddFontResource != -1 then
> junk = allocate_string( "free000.ttf" )
> if xSendMessage!= -1 then
> fonter = c_func( AddFontResource, { junk } )
> if fonter != 0 then
> junk = c_func(xSendMessage,{HWND_BROADCAST,
> WM_FONTCHANGE, 0, 0})
> -- RIGHT HERE... HOW DO I DETERMINE IF xSendMessage completed properly?
> didAddFontResource = (1=1)
> else
> errMsg = "AddFontResource failed."
> end if
> else
> errMsg = "Could not access SendMessage."
> end if
> free(junk)
> else
> errMsg = "Could not access AddFontResource."
> end if
>
>
>
> For Topica's complete suite of email marketing solutions visit:
> http://www.topica.com/?p=TEXFOOTER
>
>
3. Re: SendMessage Returns a Value?
Bernie Ryan wrote:
>SendMessageA() return values are determined by what
>message is sent so you have to LOOK at the MESSAGE you
>are sending at MSDN to see what is returned. You can
>not assume zero is always sucessful.
>
>
I did look at the message (WM_FONTCHANGE), and there's no return value
list! 
>Have you looked at my windows library it might make your job easier.
>
>
Yes, and it did. Thanks.
4. Re: SendMessage Returns a Value?
No. I see now that WM_FONTCHANGE returns 0, others may return handles
or TRUE, etc.
Evan Marshall wrote:
>
> From the SDK: The return value specifies the result of the message
> processing; it depends on the message sent.
>
> It appears that a WM_FONTCHANGE message will return 0. Maybe
> SendMessage will return 0 for any message unless you specify a
> different value?
>
> i.e.
>
> if uMsg = WM_FONTCHANGE then
> return 100
> end if
>
> will return 100 as a result
>
> whereas
>
> if uMsg = WM_FONTCHANGE then
> end if
>
> returns 0
>
>
> C. K. Lester wrote:
>
>>
>> I've looked up SendMessage info at msdn, but can't find return values
>> for success/fail. Does anybody know how to determine if the message
>> was sent or received properly?
>>
>> Here's the snippet of code I'm using...
>>
>> -- call AddFontResource
>> if AddFontResource != -1 then
>> junk = allocate_string( "free000.ttf" )
>> if xSendMessage!= -1 then
>> fonter = c_func( AddFontResource, { junk } )
>> if fonter != 0 then
>> junk = c_func(xSendMessage,{HWND_BROADCAST,
>> WM_FONTCHANGE, 0, 0})
>> -- RIGHT HERE... HOW DO I DETERMINE IF xSendMessage completed properly?
>> didAddFontResource = (1=1)
>> else
>> errMsg = "AddFontResource failed."
>> end if
>> else
>> errMsg = "Could not access SendMessage."
>> end if
>> free(junk)
>> else
>> errMsg = "Could not access AddFontResource."
>> end if
>>
>>
>> For Topica's complete suite of email marketing solutions visit:
>> http://www.topica.com/?p=TEXFOOTER
>>
>>
>
>
> For Topica's complete suite of email marketing solutions visit:
> http://www.topica.com/?p=TEXFOOTER
>
>
5. Re: SendMessage Returns a Value?
Evan Marshall wrote:
>
> No. I see now that WM_FONTCHANGE returns 0, others may return handles
> or TRUE, etc.
So, if successful, SendMessage returns 0 when sending a WM_FONTCHANGE
message to HWND_BROADCAST? What value is returned if SendMessage fails
when sending WM_FONTCHANGE using HWND_BROADCAST?
6. Re: SendMessage Returns a Value?
----- Original Message -----
From: "C. K. Lester" <euphoric at cklester.com>
To: <EUforum at topica.com>
Subject: Re: SendMessage Returns a Value?
>
>
> Evan Marshall wrote:
>
> >
> > No. I see now that WM_FONTCHANGE returns 0, others may return handles
> > or TRUE, etc.
>
> So, if successful, SendMessage returns 0 when sending a WM_FONTCHANGE
> message to HWND_BROADCAST? What value is returned if SendMessage fails
> when sending WM_FONTCHANGE using HWND_BROADCAST?
>
The return value from a WM_FONTCHANGE message should be ignored as it is not
defined. Because this is sendiong a message to many windows running in other
applications, the range of possible errors is too large to be represented by a
single return value. So there is no return value. Either the other windows will
be the message or not. Maybe you should us PostMessageA instead, as this always
returns a true/false and does not wait for all windows to be notified before
returning to your application..
--
Derek
7. Re: SendMessage Returns a Value?
Derek Parnell wrote:
>Because this is sendiong a message to many windows running in other
>applications, the range of possible errors is too large to be represented by a
>single return value. So there is no return value. Either the other windows will
>be the message or not. Maybe you should us PostMessageA instead, as this always
>returns a true/false and does not wait for all windows to be notified before
>returning to your application.
>
>
What does this statement mean: "Applications that need to communicate
using HWND_BROADCAST should use the RegisterWindowMessage
<http://msdn.microsoft.com/library/en-us/winui/WinUI/WindowsUserInterface/Windowing/MessagesandMessageQueues/MessagesandMessageQueuesReference/MessagesandMessageQueuesFunctions/RegisterWindowMessage.asp>
function to obtain a unique message for inter-application communication."
Does that apply to what I'm trying to do (which is just install a font
and then HWND_BROADCAST a WM_FONTCHANGE message, for holy's sake).
Bernie, using w32engine, how would I do the above? (I've already moved
the font file into the fonts folder, so I just need to call
AddFontResourceA and then broadcast the WM_FONTCHANGE message.)
Thanks!
Just for completeness sake, I'm pasting below how I do it now:
if gdi32 = 0 then
errMsg = "Couldn't open gdi32.dll!"
else
if AddFontResource != -1 then -- defined it earlier
junk = allocate_string( "free000.ttf" )
if xSendMessage!= -1 then -- defined it earlier
fonter = c_func( AddFontResource, { junk } ) -- call the
function
if fonter != 0 then
junk = c_func(xSendMessage,{HWND_BROADCAST,
WM_FONTCHANGE, 0, 0})
didAddFontResource = (1=1)
else
errMsg = "AddFontResource failed."
end if
else
errMsg = "Could not access SendMessage."
end if
free(junk)
else
errMsg = "Could not access AddFontResource."
end if
end if
8. Re: SendMessage Returns a Value?
----- Original Message -----
From: "C. K. Lester" <euphoric at cklester.com>
To: <EUforum at topica.com>
Subject: Re: SendMessage Returns a Value?
>
>
> Derek Parnell wrote:
>
> >Because this is sendiong a message to many windows running in other
> >applications, the range of possible errors is too large to be represented by a
> >single return value. So there is no return value. Either the other windows will
> >be the message or not. Maybe you should us PostMessageA instead, as this always
> >returns a true/false and does not wait for all windows to be notified before
> >returning to your application.
> >
> >
> What does this statement mean: "Applications that need to communicate
> using HWND_BROADCAST should use the RegisterWindowMessage
>
> <http://msdn.microsoft.com/library/en-us/winui/WinUI/WindowsUserInterface/Windowing/MessagesandMessageQueues/MessagesandMessageQueuesReference/MessagesandMessageQueuesFunctions/RegisterWindowMessage.asp>
>
> function to obtain a unique message for inter-application communication."
>
> Does that apply to what I'm trying to do (which is just install a font
> and then HWND_BROADCAST a WM_FONTCHANGE message, for holy's sake).
No. The WM_FONTCHANGE message is a predefined one that all apps should know
about. Its talking about 'normal' app-to-app communications. If one has two
applications that need to send messages to each other, the RegisterWindowMessage
is needed to create a unique message number in the system for those apps to pass.
Not required for font changes.
--
Derek
9. Re: SendMessage Returns a Value?
CK:
-- With w32engin.ew you would do this to add the font
if not AddFontResourceA(sz("free000.ttf") then
ShowLastError("AddFontResourceA Failed!")
else
ok = SendMessageA({HWND_BROADCAST,WM_FONTCHANGE, 0, 0})
end if
szfree() -- free the sz string
Bernie
