|
I need to be able to search a DataTable for a non-primary key field. I'd assume the best way is just to populate a dataset and fill the table. But how do I search the table for non-primary key values?
Nathan Lindley
.NET Aficionado
|
|
|
|
|
Something along the lines of
<br />
for each datarow in datatable<br />
if datarow.coumn(i) = searchvalue then<br />
return what you want<br />
end if<br />
next<br />
Mike Lasseter
|
|
|
|
|
I had played around with iterating the DataTable for the row, but was unsuccessful. I guess i'll play around with it a little more. Thanks.
Nathan Lindley
.NET Aficionado
|
|
|
|
|
Dim dr() as DataRow
dr = datatable.Select("FieldName = 'something'")
dr will be an array of rows from the datatable that match the query.
|
|
|
|
|
You can't assign a dataRow to an Array of datarows...i think the error says something like '1 dimensional array System.Data.DataRow cannot be converted to System.Data.DataRow' ... thanks for the response though. 
Nathan Lindley
.NET Aficionado
|
|
|
|
|
It works. I've used it many times. You must declare the DataRow variable as an array. **use the parentheses after the name of the variable**
Dim dr() As DataRow
The select function of the DataTable class will return an array of data row objects.
I am using .NET 2005
|
|
|
|
|
Good call with the casting it as a DataRow array.
Nathan Lindley
.NET Aficionado
|
|
|
|
|
I am wondering what the best approach is to consume a method that occurs when a button is clicked on a separate form. The situation is that form1 has an add record button that shows form2. after form2 is filled out/submitted, I need to fire the clear event (triggered by a button on form1), to clear out form 1. I would like to keep the button_click method private as well.
TIA
Nathan Lindley
.NET Aficionado
|
|
|
|
|
A delegate is what you need here.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
|
|
|
|
|
I was thinking something along those lines, thanks for the input, i'll proceed in that direction.
Nathan Lindley
.NET Aficionado
|
|
|
|
|
Another way to do this would be to implement an MVP or similar (MVC, Passive Screen, Supervising Controller etc.) pattern. That way you could raise the event from the view, into the associated presenter, which can Notify through a model to anywhere in the application that uses that model. Making the event not dependant on the form.
Of course, this might not be viable. It's something to think about though...
Take a look here[^] for more info on the patterns
|
|
|
|
|
Hi,
I have to write in VB.NET something like the ActiveX Controls developed in VB6. These was .ocx files and in Labview 7.1 they worked ok. I have read a lot of articles, also "Exposing Windows Forms Controls as ActiveX controls", but,in Labview, I don't find my activex in the list of availables. I think there is also a problem of registration.
Many thanks for any suggestion about.
Garraty
|
|
|
|
|
.NET Assmeblies that export COM functionality need to be registered on the machine using REGASM, which comes with the .NET Framework, not REGSVR32.
Dave Kreskowiak
Microsoft MVP - Visual Basic
|
|
|
|
|
I'm looking for a midi piano class that is written in vb.net. I have found plenty in VB6 and C, but not written in Vb.net. The class should be able to play notes that I can call from the form with parameters for note (e.g. "C" in octave 4) and for duration (millisecons). The grand piano sound of General MIDI is enough.
Here are two examples. Can someone translate one of them in VB.net? I would be most grateful!
http://www.xtremevbtalk.com/showthread.php?t=36582& (scroll few posts down)
http://www.a1vbcode.com/app-2951.asp (download link)
|
|
|
|
|
You can modify this vb.net code into a class,
Take a look here:
http://www.tomgroves.net/projects/vbmidi/[^]
Notes:
'Grand Piano Midi Patch Number is 0
'Octave 4 "C" Pitch (Midi Note Number) 108, Freq = 4,186.0090448096 Hz
Progload
|
|
|
|
|
Hey, thanks a lot!  I'll try that tomorrow. By the way, is it possible to play two notes at the same time?
|
|
|
|
|
re infecta wrote: is it possible to play two notes at the same time
In Sequence, Yes, just send the new message right after the first message.(just don't forget to close all the messages when your done with them.)
Progoad
|
|
|
|
|
OK! The code worked very well.
One question still: How to open two midi channels and play them at the same time: one playing grandpiano and the other playing percussion (drum hit)?
|
|
|
|
|
'Send a program change message. Change the last zero to any other number < 16
'to specify which channel to alter. Change '70' to any number between 0 and 127
'to set which patch to assign.
'
'sm(&HC0 + (70 * &H100) + 0)
' ^ ^
' | |
' | +---------- Midi Channel Number (0 to 16)
' |
' +----------------------- Midi Patch Number (0 to 127)
sm(&HC0 + (118 * &H100) + 1) ' <<== Change Patch to 118 "GM Synth Drum" on channel 1"
Or change Midi Channel to 9 (all notes in GM on channel 9 are different percussion instruments)
Here is a "Patch Map" for GM Patches(subtract 1 in your code) and GM Drums( channel 9).
http://jedi.ks.uiuc.edu/~johns/links/music/gm.htm[^]
Example:
sm(&HC0 + (0 * &H100) + 0) <== Change Patch on Channel 0 to "Grand Piano"
sm(&HC0 + (118 * &H100) + 1) <== Change Patch on Channel 1 to "GM Synth Drum"
sm(&H90 + ((60) * &H100) + (80 * &H10000) + 0) <== Octave 0 Middle "C" "Grand Piano" on Channel 0
sm(&H90 + ((62) * &H100) + (80 * &H10000) + 1) <== Octave 0 Middle "D" "GM Synth Drum" on Channel 1
sm(&H90 + ((38) * &H100) + (80 * &H10000) + 9) <== GM Drum kit "Acoustic Snare" Channel 9
Would play "C" (Pitch on Piano), "D"(Pitch on Synth Drum), And the Acoustic Snare.
Progload
-- modified at 15:50 Thursday 5th October, 2006
|
|
|
|
|
Hello,
I made an application, which is a kind of basic explorer window, but with a tree on the left side that has a specific structure. The problem is that in the right side window, the viewing window where you see what is in the directory you selected on the left side, those files and directories are always default in 'large icon' view while I need a 'list' view (the files have long names). The only way of changing the view now is right click, choose view and select list. To do this in every window is time consuming. How can I set default view to 'list' instead of 'large icons'?
I've been digging in in manuals and forums but can't seem to find the answer.
Thanks in advance!
Kind regards,
Maarten
|
|
|
|
|
What control are you using to display the file list? Assuming it's a ListView control, all you need to do is change it's .View property to View.Details in your initialization code or in the Properties window in the Form Designer.
Private Sub Form_Load(blah, blah) Handles MyBase.Load
ListView1.View = View.Details
End Sub
Dave Kreskowiak
Microsoft MVP - Visual Basic
|
|
|
|
|
Thank you Dave.
Well, I use a simple Forms.Webbrowser . Depending on the selected item on the left I pass a path on our server to the webbrowser who shows the files/folders on this location (other people can change that filestructure in the normal way). But shows it in Large Icon view. This should be list by default.
Greetings,
Maarten
|
|
|
|
|
Using the webbrowser control to show the file list gives you less flexibility. I don't know if you can set this view on the webbrowser control. It might take a registry modification to set the view you want. But, there is a problem. If you change it, it changes this setting for every instance of Internet Explorer the user launches, not just your instance in your app. Changing a setting that controls stuff system-side is greatly frowned upon and considered very bad practice.
If all you're doing is showing a list of file, using a ListView, and filling it yourself, you'd have much greater control over stuff like this.
Dave Kreskowiak
Microsoft MVP - Visual Basic
|
|
|
|
|
Thank you for your explanation.
I used this webbrowser because it has a preview part on the left side (if the window is big enough). It has all of the nice features an explorer window has: drag n drop, placing, deleting files/folders, renaming them... In fact, I'm just looking for a standard explorer but with on the left side my own built tree structure. Tonight (GMT +1) I'll post a printscreen of the application.
I was indeed afraid that it would hold registry modif's, not exactly what I was looking for Thanks for pointing that out. I'll check if I can delete, rename etc. files using listview...
Thank you for your help!
Maarten
|
|
|
|
|
I need to build the documentnumber in vb.net to the example below and write it to an access database. can anyone help? I have my insert working for all the other fields but this one.
documentnumber = "RTV-" & Format(Date.Today, "mmddyy") & "-" & Format(RecordID, "0000")
alewis
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
