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HI Everybody!
I just want to know what is major difference between a Dataset and reordset.
Does recordset object is supported in VB.NET
Please help me in finding the answer
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A recordset is just that, a set of records in a single table. A DataSet can represent multiple tables, with varying records, and relationships between those tables.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Hai ,
the major difference is ADO recordset is Connectted DataAccess and a single dimensionsional array to hold datas
in 1d array so if you wanna navigate through data ,u need to use movenext,movelast method,BUt in .net
is disconnected data access ,The datas are stored in datatable in multidimensionsal array like your database table.
so you can navigate the record via simple methods.and dataset is the in memory representation that can hold many tables.
you can make relationship bettween table and dataset is in XSD for so you can send through network without marshelling.
and you can use ADO recordset objects in .Net with the refernce of MsADo.dll files For more info go to MSDN APril 2003
Ishak
Programmer analyst
ITI KSA
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Dear Visual Basic & Access Experts
In my application program, I have a Access (version xp) form that calls a update event handler. In this handler I need to know if the user has clicked on the "Close" button of the form. What VBasic codes do we use to check what action triggers off the the chain of events that lead up to the update event & onwards? In particular I am interested to to check if the triggering event is the clicking of the "Close" button of the form; if so I will then write some code to handle this particular case. I tried to handle this via Close event handler but since it comes after the "Update" event, it does not work.
Please help...Cheers! Michael
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FuzMic wrote:
In this handler I need to know if the user has clicked on the "Close" button of the form.
There is no way to trace back to see what triggered the update. Since the Close event of the form fires AFTER your Update event, you can't set a flag that specifies the form is closing, so there is no way for your code to know the difference, and frankly, in the grand scheme of things, the Update event shouldn't care if the form is closing or not.
Why do you need to change the functionality of the Update on Form Close?
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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It sounds like you are trying the round-a-bout way of doing things.
Could you do what you want by having separate 'OK' and 'Cancel' buttons? With a cancel button you can prevent the Update, if that's what you're looking to do.
FuzMic wrote:
In particular I am interested to to check if the triggering event is the clicking of the "Close" button of the form
If you just want to know if the close button has been clicked when the Update event occurs, you could define a module-level boolean such as closeClicked initialized to FALSE.
In the Close button's OnClick handler, set closeClicked = TRUE. Then, in your OnUpdate handler, you can check the value of closeClicked to see if the button has been pushed.
Just make sure you set closeClicked = TRUE before the docmd.close acForm, me.name command.
I wouldn't go so far as to call this method 'sloppy', but I would think there should be a more graceful way of accomplishing your goal.
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Dear Mike the Red from Fuzzy Mike
Perhaps my message was not clear; I am not referring to a Close "Command" button that is placed on a form. I am referring to the Form Close button that comes inherent with the form on top right hand corner; in which case, how can a boolean var be flagged on clicking since there is no such event handler within the form to set it up ... UNLESS ... it is via the Window OS???.
Come what say u; Thanks & Cheers!.
Dear Dave Kreskowiak
You wrote: Why do you need to change the functionality of the Update on Form
Close?
I am using the Update event handler to do various checks such as check for duplicate, empty fields, etc. Thus if a user click on the Form Close, the form will go into the update event if the form is dirtied. At this point if the test failed, a message tells user the option to Undo or to make corrections. However since the user want to close the form, I must drop the correction option and change the message.
By the way how do Window OS handle a form close event?
Thanks & Cheers!
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I need to read values from an excel spreadsheet into a string array in VB.NET.
I can read the cells with no problems if I take the values into single dimensional variables, but I get an error when I try to read into an array.
The code fragment is:
Dim filename As String
filename = "c:\pass\userlist.csv"
Dim intRows As Integer
Dim fqn() as string
Dim r, i As Integer
' Open the Workbook in excel
Dim xlApp As Excel.Application
xlApp = CType(CreateObject("Excel.Application"), Excel.Application)
xlApp.Visible = False
Dim xlWB As Excel.Workbook
Dim xls As Excel.Worksheet
xlWB = CType(xlApp.Workbooks.Open(filename), Excel.Workbook)
xls = CType(xlWB.Worksheets(1), Excel.Worksheet)
intRows = xls.UsedRange.Rows.Count
num = intRows - 1
' Scroll through all the rows and columns retrieving values.
i = 1
For i = 0 To num
fqn(i) = CType(xls.Cells(r, 1), Excel.Range).Text
Next
xlWB.Close(False)
xlApp.Quit()
xls = Nothing
xlWB = Nothing
xlApp = Nothing
The error generated is:
An unhandled exception of type 'System.Runtime.InteropServices.COMException' occurred in mscorlib.dll
Additional information: Exception from HRESULT: 0x800A03EC.
I have added the Excel library reference (11.0)
Any help would be appreciated
Greg S
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I am trying to display nicely formatted text (as in RTF)
on a graphical background.
The standard RichTextBox control doesn't allow transparency,
so I could overlay a graphics, not does it allow me to set
a background image.
Could anybody tell me how I could get either of these to work,
or alternatively if there is a way to draw the formatted text
from a RichTextBox control on a picture or graphic?
Thanks,
Tom Verkaaik
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I need to connect a scanner(hardware device) programmatically to my vb.net applicaion.The cloth or paper that is being scanned with the scanner should directly come in the picture box in vb.net.Can anyone please help me with it? its very important.If you have an answer then please mail me at avanti_dharkar@rediffmail.com.
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You can use the ImgScan.ocx.
It exists from win 95 to windows 2000. Windows xp doesn't supply this control.
Then you can use its events to direct the scanned image to the picture box.
You can connect any ISIS or Twain scanners to it.
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Thanks, i will try using this
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OK this one has me baffled I just got done writing this program, and I only had a few typos corrected them. The program now starts up and run just fine, but it does not play the wav sounds. I have a textbox and two buttons, btnbrowse and btnplay I'm supposed to be able to browse through my hard drive, find a wav sound and then play it, could someone help me with this please. Thank you  
----------------------------------------------------------------------------
Option Strict Off
Option Explicit On
Module modauto
Sub LoadFile(ByRef inFile As String)
Dim hmem As Integer
Dim mmckinfoparentIn As MMCKINFO
Dim mmckinfosubchunkIn As MMCKINFO
Dim hmmioIn As Integer
Dim mmioinf As mmioinfo
mmioinf.adwInfo = Space(4)
hmmioIn = mmioOpen(inFile, mmioinf, MMIO_READ)
If hmmioIn = 0 Then Exit Sub
mmioDescendparent(hmmioIn, mmckinfoparentIn, 0, MMIO_FINDRIFF)
mmckinfosubchunkIn.CKID = mmioStringToFOURCC("fmt", 0)
mmioDescend(hmmioIn, mmckinfosubchunkIn, mmckinfoparentIn, MMIO_FINDCHUNK)
mmioReadFormat(hmmioIn, format_wave, Len(format_wave))
mmioAscend(hmmioIn, mmckinfosubchunkIn, 0)
mmckinfosubchunkIn.CKID = mmioStringToFOURCC("data", 0)
mmioDescend(hmmioIn, mmckinfosubchunkIn, mmckinfoparentIn, MMIO_FINDCHUNK)
GlobalLock(hmem)
hmem = GlobalAlloc(&H40S, mmckinfosubchunkIn.cksize)
bufferin = GlobalFree(hmem)
mmioRead(hmmioIn, bufferin, mmckinfosubchunkIn.cksize)
numSamples = mmckinfosubchunkIn.cksize / format_wave.nBlockAlign
mmioClose(hmmioIn, 0)
End Sub
Sub play(ByVal soundcard As Short)
Dim rc As Integer
Dim lFlags As Integer
lFlags = Callback_Function
If soundcard <> -1 Then lFlags = lFlags Or WAVE_MAPPED
rc = waveOutOpen(hwaveout, soundcard, format_wave, 0, 0, lFlags)
If (rc <> 0) Then Exit Sub
outhdr.lpData = bufferin
outhdr.dwBufferLenght = numsamples * format_wave.nBlockAlign
outhdr.dwFlags = 0
outhdr.dwLoops = 0
waveOutPrepareHeader(hwaveout, outhdr, Len(outhdr))
waveOutWrite(hwaveout, outhdr, Len(outhdr))
End Sub
Public whdr As WAVEHDR
Public format_wave As WAVEFORMAT
Public outhdr As WAVEHDR
Public bufferin As Integer
Public numsamples As Integer
Public hwaveout As Integer
Public Const MMIO_Read As Short = &H0S
Public Const Callback_Function As Integer = &H30000
Public Const WAVE_MAPPED As Short = &H4S
Public Const MMIO_FINDCHUNK As Short = &H10S
Public Const MMIO_FINDRIFF As Short = &H20S
Structure MMCKINFO
Dim CKID As Integer
Dim cksize As Integer
Dim fcctype As Integer
Dim dwdataoffset As Integer
Dim dwflags As Integer
End Structure
Structure mmioinfo
Dim dwflags As Integer
Dim fccIOproc As Integer
Dim pIOProc As Integer
Dim wErrorRet As Integer
Dim htask As Integer
Dim cchBuffer As Integer
Dim pchBuffer As String
Dim pchnext As String
Dim pchEndRead As String
Dim pchEndWrite As String
Dim lBufOffset As Integer
Dim lDiskOffset As Integer
Dim adwInfo As String
Dim dwReserved1 As Integer
Dim dwReserved2 As Integer
Dim hmmio As Integer
End Structure
Structure WAVEFORMAT
Dim wFormattag As Short
Dim nChannels As Short
Dim nSamplespersec As Integer
Dim nAvgBytespersec As Integer
Dim nBlockAlign As Short
Dim wBitsPerSample As Short
Dim cbSize As Short
End Structure
Structure WAVEHDR
Dim lpData As Integer
Dim dwBufferLenght As Integer
Dim dwBytesRecorded As Integer
Dim dwUser As Integer
Dim dwFlags As Integer
Dim dwLoops As Integer
Dim lpNext As Integer
Dim Reserved As Integer
End Structure
Declare Function waveOutWrite Lib "winmm.dll" (ByVal hWaveout As Integer, ByRef lpWaveoutHdr As WAVEHDR, ByVal uSize As Integer) As Integer
Declare Function waveOutPrepareHeader Lib "winmm.dll" (ByVal hWavein As Integer, ByRef lpWaveInHdr As WAVEHDR, ByVal uSize As Integer) As Integer
Declare Function mmioRead Lib "winmm.dll" (ByVal hmmio As Integer, ByVal pch As Integer, ByVal cch As Integer) As Integer
Declare Function waveOutOpen Lib "winmm.dll" (ByRef lphWaveIn As Integer, ByVal uDeviceID As Integer, ByRef lpFormat As WAVEFORMAT, ByVal dwCALLBACK As Integer, ByVal dwInstance As Integer, ByVal dwFlags As Integer) As Integer
Declare Function GlobalAlloc Lib "kernel32" (ByVal wFlags As Integer, ByVal dwBytes As Integer) As Integer
Declare Function GlobalLock Lib "kernel32" (ByVal hmem As Integer) As Integer
Declare Function mmioAscend Lib "winmm.dll" (ByVal hmmio As Integer, ByRef lpck As MMCKINFO, ByVal uFlags As Integer) As Integer
Declare Function GlobalFree Lib "kernel32" (ByVal hmem As Integer) As Integer
Declare Function mmioOpen Lib "winmm.dll" Alias "mmioOpenA" (ByVal szFileName As String, ByRef lpmmioinfo As mmioinfo, ByVal dwOpenFlags As Integer) As Integer
Declare Function mmioDescendparent Lib "winmm.dll" Alias "mmioDescend" (ByVal hmmio As Integer, ByRef lpck As MMCKINFO, ByVal x As Integer, ByVal uFlags As Integer) As Integer
Declare Function mmioReadFormat Lib "winmm.dll" Alias "mmioRead" (ByVal hmmio As Integer, ByRef pch As WAVEFORMAT, ByVal cch As Integer) As Integer
Declare Function mmioClose Lib "winmm.dll" (ByVal hmmio As Integer, ByVal uFlags As Integer) As Integer
Declare Function mmioStringToFOURCC Lib "winmm.dll" Alias "mmioStringToFOURCCA" (ByVal sz As String, ByVal uFlags As Integer) As Integer
Declare Function mmioDescend Lib "winmm.dll" (ByVal hmmio As Integer, ByRef lpck As MMCKINFO, ByRef lpckparent As MMCKINFO, ByVal uFlags As Integer) As Integer
End Module
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You've got WAY too much code for this. How about getting some pointers from How To Play a Waveform (.WAV) Sound File in Visual Basic[^] on MSDN. It's written for VB4, VB5, and VB6, but is easily convertable to VB.NET code.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Hi, I have the following two procedure:
Private Sub btnEvalGuide_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnEvalGuide.Click
' the code work here.
' ...
End Sub
Private Sub btnUseDtGl_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnIntVuDmExp.Click
' the code work here.
' ...
' ...
' need to call btnEvalGuide.Click
' but i don't know how to do it.
End Sub
When the code in btnIntVuDmExp.Click run it do it task and finally i need it to call to btnEvalGuide.Click. But i don't know how to do it. Can anyone give me a suggestion???
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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it seems that btnEvalGuide and btnIntVuDmExp both are buttons .u can can use
call btnEvalGuide_Click(sender,e)
that's all.
good luck
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Thank you very much for your comment. I will try to do that, but if it is not working I will do it in a separate procedure then make a call to that procedure instead.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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First of all, your btn name and the Handles control name really should reference the same button in the second click handler you have shown above.
Second, if you need to run a common set of code from two or more control event handlers, you should move the code out of the control event handler and into a separate procedure. In the long run this will make your code much clearer and more maintainable. Calling control events from other control events is not a particularly good practice in terms of design.
I would rewrite the above code as:
----------------------------------------------------------------------------------------------
Private Sub btnEvalGuide_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnEvalGuide.Click
' the code work here.
' ...
'Call common procedure here
DoMyCommonProc()
End Sub
Private Sub btnIntVuDmExp_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnIntVuDmExp.Click
' the code work here.
' ...
'Call common procedure here
DoMyCommonProc()
End Sub
Private Sub DoMyCommonProc()
'Put common code in this procedure and call from both click events
End Sub
----------------------------------------------------------------------------------------------
Robert
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Thank you very much for your comment. I will consider this opinion if there is no more choice.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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i m trying to make a vcd cutter like software in vb.net. i m using a binery reader to split the files.if i split the file from begnige it's playes fine but if i try to split it from sommeware middle the the clip is not working.can any one help me in this
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The clip is not working because the beginning of the file has information about Audio and Video codecs, compression ratios, bit rates, etc.
If the player cannot find this information at the beginning of the file, it won't be able to play it.
You'll need to research the format specifications for whatever format(s) you want to support so that you can properly format your output, or find a third-party library to handle this part of the proccess.
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i know that much but can u tell me how i can format the output of me file or any persone who can help me on this
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Hi,
I'm trying to do something very simple, however I seem to going rouund in circles!
1. I have an Array which is loaded from a file, I then load it into a DataTable, at the same time adding Column names.
2. I create a DataView from the Datatable.
3. I asign the DataView to a Datagrid using Datagrid.DataSource = DataView
4. Run, everything works fine.
The issue...
I want to change the size of the columns and hide some occasionally. I tried using DatagridTableStyles are per several submissions on the web, but it won't work.
Any ideas?
Is there a simple way of doing this?
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Using DataGridTableStyles IS the simple way of doing it, and as it happens, the only way.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Ok, thanks for that at least I'm in the right place.
In that case then please can you help me to understand when the following code doesn't work, it's probably something simple...
I'd really appreciate some assistance...thanks
What Happens > All the data loads fine, the Datagrid1 formating works ok, but the columns are not adopting the table styles I created!
coding...
-->Step 1 load up 'Product' Array with Data
-->Step 2 load up Column collection...
Private Sub LoadColumnCollection()
productColumnCollection.Add("Level3")
productColumnCollection.Add("Level4")
productColumnCollection.Add("Rep_ITEM")
productColumnCollection.Add("Description")
productColumnCollection.Add("Ext_Description")
productColumnCollection.Add("End_Date")
productColumnCollection.Add("Price_From")
productColumnCollection.Add("Price_To")
productColumnCollection.Add("Price_Comments")
productColumnCollection.Add("RRP")
productColumnCollection.Add("Min_ISP")
productColumnCollection.Add("Max_ISP")
productColumnCollection.Add("ISP%SIP")
productColumnCollection.Add("%Margin")
productColumnCollection.Add("Units")
productColumnCollection.Add("SIP")
productColumnCollection.Add("Pack_Priority")
productColumnCollection.Add("Exculsive")
productColumnCollection.Add("Despatch_Date")
productColumnCollection.Add("ITEM_Code")
productColumnCollection.Add("Lenght_Av.")
productColumnCollection.Add("Unit_EAN")
productColumnCollection.Add("Case_EAN")
productColumnCollection.Add("Outer_EAN")
productColumnCollection.Add("Length")
productColumnCollection.Add("Width")
productColumnCollection.Add("Height")
productColumnCollection.Add("Case_Length")
productColumnCollection.Add("Case_Width")
productColumnCollection.Add("Case_Height")
productColumnCollection.Add("Gross_Weight")
productColumnCollection.Add("H")
productColumnCollection.Add("Pallet_Weight")
productColumnCollection.Add("Cases_Per_Layer")
productColumnCollection.Add("Layers_Per_Pallet")
productColumnCollection.Add("Reason_For_Change")
End Sub
Private Sub LoadColumnNames()
Dim row As Integer
Dim dC As DataColumn
' set product table up...
productTable = New DataTable("Product Table")
' construct table columns and names...
Try
For Each Nm As String In productColumnCollection
dC = New DataColumn(Nm)
dC.DataType = System.Type.GetType("System.String")
productTable.Columns.Add(dC)
Next
Catch
End Try
End Sub
-->Step 3 load up Column names into table...
Private Sub LoadColumnNames()
Dim row As Integer
Dim dC As DataColumn
' set product table up...
productTable = New DataTable("Product Table")
' construct table columns and names...
Try
For Each Nm As String In productColumnCollection
dC = New DataColumn(Nm)
dC.DataType = System.Type.GetType("System.String")
productTable.Columns.Add(dC)
Next
Catch
End Try
End Sub
-->Step 4 load up Dataview...
Friend Sub ViewConstructor()
productTableViewDefault = New System.Data.DataView(productTable)
productTableViewDefault.AllowNew = False
productTableViewDefault.AllowDelete = False
productTableViewDefault.AllowEdit = True
End Sub
--> Step 5 Assign view to Datagrid1...
Datagrid1.Datasource = productTable
--> Step 6 Format Datagrid1...
With DataGrid1
.BackColor = Color.GhostWhite
.BackgroundColor = Color.Lavender
.BorderStyle = BorderStyle.None
.CaptionBackColor = Color.RoyalBlue
.CaptionFont = New Font("Tahoma", 12.0!, FontStyle.Bold)
.CaptionForeColor = Color.Bisque
.CaptionText = "Installed Software"
.Font = New Font("Tahoma", 8.0!)
.ParentRowsBackColor = Color.Lavender
.ParentRowsForeColor = Color.MidnightBlue
.HeaderBackColor = Color.DarkBlue
.HeaderForeColor = Color.White
End With
'set up style...
Dim objDataGridTableStyle As New DataGridTableStyle
Dim objTextCol As New DataGridTextBoxColumn
' set alternate background colour...
objDataGridTableStyle.AlternatingBackColor = Color.WhiteSmoke
' set the mappingname for the DataGridTableStyle...
objDataGridTableStyle.MappingName = "productTable"
'set column 1
objTextCol.MappingName = "Level3"
objTextCol.HeaderText = "Level >3"
objDataGridTableStyle.GridColumnStyles.Add(objTextCol)
'set column 2
objTextCol = New DataGridTextBoxColumn
objTextCol.MappingName = "Level4"
objTextCol.HeaderText = "Level >4"
objDataGridTableStyle.GridColumnStyles.Add(objTextCol)
'final step, add datagridtablestyle to datagrid...
DataGrid1.TableStyles.Add(objDataGridTableStyle)
End of code...
Thanks
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