how to use DDE server - delphi

Can I get a little code example to use DDE as a server? I know how to use the client part, but can't figure setting up my app to act as a server and receive data.

Have a look in your Delphi installation for a folder called DDEDemo. It's a DDE project that Delphi use to ship with (I'm not 100% sure it's still included, but have a look). The demo includes a DDE client and server.
Edit - Try this link for some example code.

It is so easy to use the DDE server that you don't even need sample code. You can do it just at designtime inside the Delphi form designer:
To create a server that sends out data:
Drop a TDDEServerConv and
TDDEServerItem on your form or data
module.
Connect the server item to
the server conversation (set
DDEServerItem1.ServerConv=DdeServerConv1
using object inspector, there is a
drop down list, but double clicking
it is enough).
Set the DDEServerItem.Text value to some valid text value (ie 'A')
To receive data, you might want to have macros that are executed by the DDE client that pass data to the server. For this you use the DdeServerConv.OnExecuteMacro event. Try dumping the parameter Msg:TStrings to a memo like this:
Memo1.Lines.Assign(Msg);
Now save and run your project.
To test it in excel type in:
=Project1|DdeServerConv1!DdeServerItem1
The excel dde client syntax parts are Application name followed by vertical bar, conversation name, followed by exclamation mark, then item name.
And you will see the value (A, or whatever you put into the Text property in the item) appear in Excel.
That's a working single item DDE server without any code written by you.
I generally find that I create the conversations and the items at runtime, instead of at designtime, in a real world scenario that is more useful for me.
For older (non unicode) Delphi versions there is also a full featured commercial product called Django that helps a lot with DDE work.
I think also you might be looking for information on how to write a "DDE Poke" command handler on the delphi side. I don't have a demo for that. I tried it, and the obvious things didn' quite work right for me (the item on your server has an OnPoke event, I wrote a simple client, called PokeData, and it didn't work).

Related

Can't connect to SQL Server in Delphi 10.3

I just installed the community version of Delphi, Delphi 10.3
I want to use FireDAC in stead of ADO,
so I want to test connections to SQL Server using FireDac but it is a complete disaster.
I dropped a FDConnection component on the form, and want to configure it to use Sql Server
There I notice I can choose from many DriverNames but not MSSQL
Why is that ?
So I tried the FireDAC Explorer but this has even more mysteries.
I add a new Connection Definition and there I can use MSSQL, but I cannot save this definition.
The save and save as button are disabled.
So I enter all the parameters I need, and yes, it opens my SQL Server database. I can see all tables, views, procedures... And I can even open a table to see the first 10 rows.
Great, if I could only save this definition...
Everytime I open the FireDAC Explorer my new definition is still there, but all parameters are not stored. I have to enter them all every time again.
But, no problem I think. I copy the parameters from the working definition and paste it in the parameters from the FDConnection on my form.
The parameters look like this
User_Name=xx
OSAuthent=No
Server=123.456.789.987\GTT
Database=DB_Test
DriverID=MSSQL
Name=DB_Test
Hm, interesting. Now it does show MSSQL as drivername. So let's set the connection property to true.
Now I get this error (allthough this is working fine in FireDAC Explorer with these parameters)
[FireDAC][Phys]-300. Driver [MSSQL] is not registered. To register it,
you can drop component [TFDPhysMSSQLDriverLink] into your project.
Well alright, if that is all I need to do.
But, it seems I don't have the component TFDPhysMSSQLDriverLink
I have others for all kind of databases, but not this one.
It seems there is something missing, but the errors don't give me much of a clue
So I am hoping there is someone here that understand the errors and can help me to fix this
EDIT
I found this question here with an accepted answer, but I don't know how to use that answer. I have no clue how to use the License manager to register FireDAC

Intraweb - web application - users sessions

Today I started to write my first web application and I can't pass one step.
Everything works almost fine... I can connect to the server and open website. Problem is when I open browser and type the same address on the second pc, then I get te same data as on the first one.
Detailed...
Application has two forms, first is for login, and second one is for receiving data.
When I login on the first pc and second form shows up, and then I open browser and put the address of the server on the second pc, I see the second form after login from first pc.
What I should do in this case? I tried to find the solution in the net, but I couldn't :(
If you are using any Delphi IDE after XE3 (including) and using the IntraWeb edition that comes with Delphi you must upgrade in order to have it working correctly. It is free, and more information can be obtained here:
http://atozed.com/IntraWeb/Download/FreeKeyRequest.EN.aspx|
After upgrading (if this is your case) I suggest you to take a look at one of the IntraWeb demos, here:
https://iwdemos.codeplex.com/SourceControl/latest
There is a demo named Features that shows you exactly how to create a multi form application. To be honest, I work with IntraWeb for a long time and I've never seen that. Unless you are using some global var to hold your "current" active form. Have in mind that IntraWeb is a fully multithreaded application and global vars should not be used, unless you have some mechanism protecting concurrent access (but you should get rid of them and use ServerController properties instead).
Thnks for your quick reply.
I work with Delphi from some time, but I never used Intraweb, I worked with ComPort and IP works for I/O devices. I have XE7 and I upgraded Intraweb to 14.0.52.
I can't find a good file exchange server to put my application for sharing with you. If I find somethin I will post it below.
You can check the code and other settings of my simply project. I put the web application inside the link below, it is without the .exe file.
https://www.dropbox.com/s/75zurcew0zr363x/Project1.rar?dl=0
Thanks for your help.

How can I make the 'Showmessage' dialog wider so it fits the text?

I'm showing where a file has been saved by using 'Showmessage' (in Win 7).
When the file path is long it gets truncated and elipsis get inserted.
eg
the path
C:\Users\Admin\Documents\SubFolderOne\AnotherSubFolder\MyFile.csv
gets displayed as
C:\Users\Admin\Documents\SubFolderOne\Ano...\MyFile.csv
Is there a way to make the message box wider and show all of the filename and path?
I have read this
http://zarko-gajic.iz.hr/displaying-long-non-breakable-text-file-path-in-messagedlg-truncationellipsis-issues/
which explains some of the reasoning and gives a rather unsatisfactory method for a TTaskDialog and I also I realise I could make my own form to act in the same way as Showmessage but I am wondering if there is a simpler solution using just Showmessage.
Is a simpler solution using just ShowMessage?
No there is not.
I can think of three obvious approaches, although doubtless there are more.
Create your own dialog
There's nothing particularly magical about a dialog. You can perfectly well create them yourself, and so have complete control over their appearance. The downside of course is that it can be hard to match the native platform appearance. Especially when you consider all the different Windows versions that you are typically expected to support.
Use CreateMessageDialog and customise this Delphi form
You can call the RTL function CreateMessageDialog to obtain a Delphi form that can be used to display your message dialog. You then have the opportunity to customize this dialog in any way you please.
Use the task dialog API
The task dialog API, introduced in Vista, affords control of the dialog width. Call TaskDialogIndirect, and specify a non-zero value for cxWidth.
Before ShowMessage put:
UseLatestCommonDialogs:= false;
I use Delphi 10.2 and it works.

Delphi XE Datasnap: Server methods missings when DSServerModule is load dynamically

I have Datasnap Server (DBX) that scans at startup a directory, loads the BPLs (containing the DSServerModules) and then registers them in order make them available from remote.
It all works fine for functions and procedures that use primitive types (such as integer, string and so on) but from client I cannot see any method that has "structured" variables.
For example I tried to add a function that returns a TJSONValue (as I saw on an example) but the method is not visible from client.
Strangely enough, the same function is available (and works) if the DSServerModule is added statically to the project).
Any Guess?
I didn't attach any code because it is part of a quite big project.
If need I'll provide a small example.
Cheers,
Mirko

How do I make a TLinkLabel work in Delphi?

I put a TLinkLabel on my form, filled it in with a caption including a valid HTML link, and got some nice blue underlined text. When I ran the program, I expected it to invoke Firefox (my default browser) and open the link automatically. Apparently that's not the case.
The helpfile says I have to code this in an OnLinkClick event handler. It doesn't say anything about how to do that, though. It'll pass in a string value called "Link". How do I say "invoke the default browser and have it open Link"?
You can call ShellExecute.
I wrote this method for generic calls, and should works in your case.
procedure ShellOpen(const Url: string; const Params: string = '');
begin
ShellAPI.ShellExecute(0, 'Open', PChar(Url), PChar(Params), nil, SW_SHOWNORMAL);
end;
In your code you should call this
procedure TForm1.LinkLabelClick(Sender: TObject);
begin
ShellOpen(LinkLabel.Caption);
end;
I have all sorts of problems with TLinkLabel that ships with delphi 2010.
a) The control does not render as a hyperlink but as a simple label text on the form. b) the cursor does not change to point out this is a link even though I set the Cursor property. c) the OnLinkClick event does not fire at all.
I am working on windows 7.
So, as far as I am concerned, TLinkLabel does nothing as it should and is useless. ShellExecute is the only solution and must be placed in the OnClick event.
TLinkLabel provides a label that looks like a link. It's your job as the programmer to make it act like a link because only you can know what links are supposed to act like in your program. You wanted the label to automatically open the user's default Web browser using the URL in the label, but that's not the only thing links do. For example:
Internet Explorer is not my default browser, but when I click a link in Internet Explorer, I do not expect the linked page to open in Firefox.
When I click a link in the help program, I expect the linked topic to appear in the help program, not in any Web browser at all.
The preference pages in Eclipse are very complicated. Settings on one page are sometimes related to settings on another page. There are links on those pages that take the user directly to the related page. There is no URL and no HTML involved in this case, and yet they're still labels with underlined text.
Some programs try to offer a choice between opening links in new windows versus re-using old windows. You can't implement that feature without knowing which browser is in use. Your program might offer the user a choice to ignore the default browser setting and always use a specific one. To do that, your UI control can't make too many assumptions about what the program is supposed to do.
I'm guessing you're referring to a TLinkLabel control that comes with Delphi. (My versions don't have such a component.) I imagine that the Delphi control is meant to mimic the one in the .Net class library. It can hold multiple links, and each link can do something different.
If you want a control that always does the shell's default action for URLs, then consider using a different TLinkLabel; the one by Alexander Bach does exactly what you expected. It's from Delphi 3, but it should work unmodified in all later versions as well, including Delphi 2009. If you look at the code, you'll see how it works. It simply calls ShellExecute, as Cesar's answer demonstrates.
LOL, it's funny. So instead of setting crHandPoint as cursor, colored and underlined font and filling the OnClick event to standard TLabel we have component that knows link tag and which at all I need to supply with same On(Link)Click event :))
Only thing it is good for is that it makes easier to embed link into some text and that it is using system style of link...
p.s.: really you have to put Some text with link into the Caption and setup OnLinkClick to that ShellExecute...
I use a control called TInternetLabel instead. It does exactly what you want: on click it opens the browser so you don't have to put code in the OnClick event.
I tried this solution but it still gave problems in Delphi XE4, probably becasue ShellOpen does not understand the HTML-code in the Caption.
What worked for me was a combination of Cesar Romero (the basic code), Adam Feistner (The HTML-code in the Caption) and an older solution:
Put the URL in the HINT field.
Change the line: ShellOpen(LinkLabel.Caption);
to
ShellOpen(LinkLabel.Hint);
This worked for me.

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