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Communications between applications

26-May-04 9:47

I fixed the linked post for posterity.

If you want to see an example of what you need to do, you could use the designer in VS.NET. The DataAdapter-related designers will help you fill all the commands of a DataAdapter and the InsertCommand will contain both an INSERT and SELECT statement for the very reasons I mentioned.

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Guinness4Strength26-May-04 5:48

Guinness4Strength

26-May-04 5:48

Hello,
I'm entering new territory for me here, so I appologise in advance if I dont't use the correct terminology. I want to communicate between to programs on the same computer. The best annaology I can come up with is how Winamp or MediaPlayer allows you to enqueue files from the Shell menu to the running application. I want to specify a file to import into a running application. Whats the best way (no security needed) to create a communication channel where I can send a string from one app to another. I've started looking into Remoting, but this might be overkill. Could I use the FindWindow and SendMessage APIs to send a string to my application ? If so how do I check for these incoming messages ?
Any suggestions would be helpful. Thanks.

Re: Communications between applications [EDITED]

Dave Kreskowiak26-May-04 6:07

Dave Kreskowiak

26-May-04 6:07

I'm going to let other people get into some of the details because my experience with Remoting is lightweight compared to other people here...

You're looking to have a 2nd instance of an app throw a string, or whatever else, at the 1st instance of your app, then quit.

Remoting is not the overkill you would think it is. It's actually going to give you the best bang for your buck as far as flexibility, being able to pass any object you want and send information back to the caller.

Using the SendMessage and FindWindow API's is actually a VERY limited method of communication and frankly, not that reliable in this case you have to garantee that the window that your talking to isn't the window your sending from. In others words, an instance of an app can end up talking to itself instead of a previous instance. Plus, you have to register your own custom message and you would have to pass a pointer to a String or other object. You can't send a copy of the string itself.

There are a couple of other methods that are written up in these articles on CP here[^], here[^], and here[^]. But these methods are not elegant, more like hacks really (no offense Big Grin | :-D

) because they can't be written in totally managed code, and have their pitfalls and, I think, are limited to just passing a single string.

RageInTheMachine9532
"...a pungent, gastly, stinky piece of cheese!" -- The Roaming Gnome

Re: Communications between applications [EDITED]

Guinness4Strength26-May-04 7:24

Guinness4Strength

26-May-04 7:24

Thanks for the info....you suppose you could suggest an approach in Remoting ? Since I have no experience, your "lightweight" experience is more than I have...

crystal reports question

blankg26-May-04 5:24

blankg

26-May-04 5:24

is it possible to create a new group at run time?

Dave Kreskowiak26-May-04 5:34

Dave Kreskowiak

26-May-04 5:34

With the VERY limited experience I have with Crystal Reports, no you can't. I believe report classes are immutable at runtime.

RageInTheMachine9532
"...a pungent, gastly, stinky piece of cheese!" -- The Roaming Gnome

Heath Stewart26-May-04 5:37

26-May-04 5:37

The report definition in CR for VS.NET is read-only. You could take a look at their newer, full-fleged products. This isn't a Crystal Reports forum, though, so you should direct your questions to their site.

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Nick Seng26-May-04 15:34

Nick Seng

26-May-04 15:34

I believe you would need the "Advanced Developer" version of Crystal Report 10 to be able to do that.

"if you vote me down, I shall become more powerful than you can possibly imagine" - Michael P. Butler.

Duplicate menus with checkboxes

blankg26-May-04 21:46

blankg

26-May-04 21:46

THanks ,I'll try out their trial version

goldoche26-May-04 5:16

goldoche

26-May-04 5:16

Hi!

I have a menu using the Checked property on top of a window and I want to duplicate it:
1: As a drop down menu on a ToolBarButton
2: As a popup menu on the status bar.

- I have created my menu
- I have copied my menu into a Context menu this way:

typeContextMenu.MenuItems.Add(subMenu1.Index, menuItem1.CloneMenu());
typeContextMenu.MenuItems.Add(subMenu2.Index, menuItem2.CloneMenu());

(suppose the menu contains 2 MenuItems)

Anyway, everything works fine BUT the checkboxes don't update in the context menu! They only update in the initial Menu...

I understand that this may be because the ContextMenu works on a copy of the initial menu... so I tried to assign them without the CloneMenu Method but then the initial menu disappears!

What can I do?

Re: Duplicate menus with checkboxes

Heath Stewart26-May-04 5:32

26-May-04 5:32

When you clone a menu item, you make a copy of it. The checks are disjoint and you would then have to update them all. Also, a menu item can only belong to one menu, which is why the initial disappears when you add it to another menu.

Just keep a list or array or something of related MenuItems and update each's checked state.

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Fun with a datagrid

Adam °Wimsatt26-May-04 5:14

Adam °Wimsatt

26-May-04 5:14

I'm sure the answer to this is obvious, but I haven't been able to find an example of this yet...

I have a datagrid that I have made editable. How do I get rid of the columns for a row that is editable, but leave the columns on all the other datagrid rows?

[Edit] This is for a Website so I'm looking for a solution for the Web DataGrid control [/Edit]

Re: Fun with a datagrid

DougW4826-May-04 5:23

DougW48

26-May-04 5:23

You'll need to create a DataGridTableStyle for you grid. This should get you started:

DataGridTableStyle style = new DataGridTableStyle();<br />
style.MappingName = "Table";  // Name of the DataTable<br />
<br />
DataGridColumnStyle Style1 = new DataGridTextBoxColumn();<br />
Style1.Width = 100; // Width of that column<br />
Style1.MappingName = "TableColumn1";  // Name of the column in the DataTable<br />
Style1.HeaderText = "Column1";  // This will be displayed as the column header<br />
<br />
DataGridColumnStyle Style2 = new DataGridTextBoxColumn();<br />
Style2.Width = 100; // Width of the column<br />
Style2.MappingName = "TableColumn2"; // Name of the column in the DataTable<br />
Style2.HeaderText = "Colunn2"; // This will be displayed as the column header<br />
<br />
style.GridColumnStyles.AddRange<br />
(<br />
   new DataGridColumnStyle[]<br />
   {<br />
	Style1, Style2<br />
   }<br />
);<br />
<br />
dataGrid1.TableStyles.Add(style);

As you can see, you can put any columns in your datagrid from your source that you choose, and omit the rest. You can do a lot with the datagrid, but this is a good starting point.

Re: Fun with a datagrid

Adam °Wimsatt26-May-04 5:38

Adam °Wimsatt

26-May-04 5:38

I guess I forgot to mention that I'm dealing we the Web DataGrid and not the Windows Forms datagrid. Thanks for the reply though. I couldn't find DatGridColumnStyle for the Web DataGrid.

Dataadapter Updates

MrJJKoolJ26-May-04 5:03

26-May-04 5:03

Hi,

If I send a dataset to a dataadapter to update a database the second time after its been disconnected from the dataadapter will it pick up only the rows that need to be added to the database and not the ones already in the database? and will this also update rows in database that have changes in existing rows? I am retrieving a dataset from file and adding rows to it then feeding the new rows to the dataadapter to update DB but only want the new rows to be added and not of course existing ones.

Thanks,

JJ

Heath Stewart26-May-04 5:13

26-May-04 5:13

If you have all the command properties set to a valid command object, then the DataAdapter will only update existing rows, insert new rows, and delete removed rows. Make sure you do not call DataSet.AcceptChanges yourself, or the DataAdapter will not see any changes. You should also combine your INSERT statement with a SELECT statement (separated by a semi-colon) so that auto-filled fields are updated in the DataSet.

If you're marshaling the DataSet across remoting boundaries, you might consider calling DataSet.GetChanges and send only the DataSet containing those changes. You would then, of course, have to call DataSet.Merge to merge the changes. This is really only useful when you need to marshal the DataSet across remoting boundaries.

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MrJJKoolJ26-May-04 5:23

26-May-04 5:23

Hi Heath,

Ok the DataAdapter is in a web service on the same pc as the database. I am sending the dataset over the network to the web server. Does this constitute going across remoting bounderies?

Thanks,

JJ

Heath Stewart26-May-04 5:26

26-May-04 5:26

No. Going across remoting boundaries would be like sending the DataSet to a Web Service from a client proxy, or to a Remoting object. There's other examples, too, but if the DataAdapter is just issueing commands based on the DataSet changes, that is normal behavior.

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MrJJKoolJ26-May-04 5:36

26-May-04 5:36

Maybe you misunderstood my design. I am sending a dataset to the web service from a PDA and the web service is updating the DB. So I would assume I am going across remoting boundaries, correct?

JJ

Heath Stewart26-May-04 5:40

26-May-04 5:40

You said,

If I send a dataset to a dataadapter to update a database...

I saw nothing in there about sending a DataSet across the wire.

Then yes, the client should call DataSet.GetChanges and send the returned DataSet to the Web Service. If you get a DataSet back with the changes (don't expect the method to modify your instance - one has to be returned), then call DataSet.Merge on the original database, passing the DataSet you got back from the Web Service as the parameter. You should call Dispose on the DataSet you get back from the Web Service to free-up some memory.

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MrJJKoolJ26-May-04 5:42