I have a DataSet(dssongs) with a DataTable(dtsongs) on a form(songsForm).
I am adding rows to the dataTable using the following
Dim dr As DataRow = songsForm.dtSongs.NewRow
dr.Item("colSongFile") = file
dr.Item("colSongTitle") = ""
[Code]....
How do I refer to a DataTable on another form?
i have 2 forms. In form1, I created a dataTable with 10 rows of data to be display in Form2. However, when in Form2, I can see all the info. But when i created an button to count the number of rows, it return 0 where there is obviously 10. I understand that in Form2, in order to count the table, i have to create a new variable for DataTable. And this variable in Form2 is actually create a new dataTable. is there a way for me to access the same dataTable that is created in Form1 in Form2?
View 3 RepliesI have a base form and I am trying to get the DataSource of the ActiveControl if the control is a datagridview.What I have so far is:
Dim curControl As Control = Me.ActiveControl
Dim ControlType As String = curControl.GetType.ToString()
If ControlType = "System.Windows.Forms.DataGridView" Then
[code].....
my form have a datafridview to display my datatable in my access database. and my database have 3 tables.in my database have "computer","booking status"," reservation" and this 3 tables are link together. which my parent table is "computer", then we can level in then we can see the "booking status", and then we can level in and see the "reservation"
so now i have a problem of this. i want to show them in a relationship view (or should i said it as parent and child relationship) just like we view in access database. can it be done? if can how i gonna do it. and how i gonna code for that?
I am trying to write general function to set the attributes of the command button and want to access this function from any forms.But I am getting error in this function.[code]
View 1 Repliesi have tried googling this and cant find a way to do this, i hav 2 projects in the same solutions, i am trying to write a bit for Solution1_Project1_Form1 to open a windowsForm in Solution1_Project2_Form2.
Start main application & View 2nd application FROM within the main application.
Start the 2nd application WITHOUT using the main application.
both applications need to read and write to a database, i dont think this makes a big diferance but thought i would mention it
I have about 60 Child forms
Each have a variable with same name.
In Main form I want to set the value of the variable of the active child.
One way of doing that is like
Select Case Me.ActiveMdiChild.Name
Case "formName"
frmformName.Variable=0
I donot want to do that as it involves writing many cases and I may miss some.
Is there some other way of doing it .
I tried
Dim O as Object = Me.ActiveMdiChil
O.VariableName= 0
and its various variants but its not working
I am trying to figure out how to have a form running in a loop waiting for the user to input something....
such as:
private function looping()
while 1=1
if textbox.text = "hi" then do_something()
endwhile
end function
How can I do this? threading? Backgroundworker?
I want a string and a listbox, both which are in a form to be modified by an instance of a class method. Should (could I):
1. Pass the entire form to the class method as parameter.
2. Pass the listbox and the string to the method as parameters.
What's the best approach to get access and modify this string and listbox on the form.
I only managed make the form always on top. But what I want is when the form is on top, user cannot access the other application in the windows.
For example : Some messagebox won't let users access the other application until the users hit the OK button.
I was a vb6 user, done a few projects only with forums Now i am moving to vb.net(vb2010) and i have some trouble.Lets say we have a form(form1), a module(mod1) and a textbox on the form1.
i want to start a Sub (DoWork) in the module but in a new thread.
Dim Thread1 As System.Threading.Thread
Thread1 = New Threading.Thread(AddressOf mod1.DoWork)
Thread1.Start()
The DoWork sub does some stuff and when it's finished i want to change the text of a textbox1 in the main form and start another sub (DoWork2) on the main form under the main thread not the one DoWork is running under.
Plese do not refer me to another post that mighe give me a part answer, try to explain to me what i have to do and why.
I build my project and i got some problems. First i want to print barcode for books(toolstripmenu item). but i cant. here's the code that i found:
[code..]
second problem is printing again. i want to print my MS ACCESS .mdb from child datagridview's records.
third one i want to save and load(with dialogs) my database from main form to child forms' datagridview.and the last one is help provider. i prepare my own .htm help file, when press F1 it opens. but i dont know how to call provider to toolstripmenuitem and help provider keep my computer's path so when i call provider another computer, the programme cant find the path.
Is there any possibility to access directly from a Windows form created in VB.net a protected Excel file? I mean, that the password for opening xls file to be stored in VB.net Windows form. I also have the same problem for a Microsoft Access protected file.
View 2 RepliesI used this
[Code]...
Nevertheless, mycontrol remains empty after this.
my application adds fields to a table dynamically, is it possible to 'rebuild' a datatable or even change its SQL so that my grid picks up the new fields?
View 6 RepliesI would like the main form I am designing in VB.net to appear as quickly as possible. As a result I don't want to fill a datatable in the load event but instead fill it as soon as the form appears, in the background.Then when a user clicks the button a listbox can quickly be populated.
With this in mind I called a function to fill the datable from the _Shown event. The trouble is that the form freezes until the query executes, making the process pointless for my needs.
Does anyone know how to keep the form active while the datatable fills silently in the background?
created a small application that I'm able to add items from an access DB to a ataGridView.Now, My questions is: suppose that I have a list of item in this DGV,containing name and Quantity. Now I would like the database to be updated with new values on Quantity column, something lke this: (Current values - Quantity on DGV).
View 1 RepliesWay to access datatable rows
[code]...
All I want to do is build some kind of table-like or grid-like control in my form that has two columns. An element in the first column should be a checkbox that is changable by the user, and an element in the second column is some un-editable text. Of course, when the user checks or unchecks a checkbox, I have to be able to handle that event and figure out which row it came from.I've been trying this all day with no luck. Do I use a ListView or a DataGridView? If the answer is DataGridView, do I add columns and rows to it directly or do I try to make a DataTable which I then assign to the DataGridView's "DataSource" property?Is is possible to make editable checkboxes in a DataTable? I succeeded in making checkboxes by making a DataColumn of type boolean, but then I couldn't check or uncheck them during runtime.
[code]...
but then I couldn't figure out how to add rows. The examples online all assume that there is only string data in each row.Also there is apparently a type called DataGridBoolColumn? What is that all about?My point is there are a lot of different objects out there with similar sounding names
im using vb.net winform.i want to update a datatable to sqlserver. but before that. i need to check by comparing it to another datatable(same structure but contain new data). i need to insert new data only.
View 4 RepliesSo, I'm trying to do things according to accepted convention as much as possible.
I have a DataTable that holds data that is read in from an XML at the launch of the program. This DT contains data about folders that are added by the user. It is primarily accessed by a single form, but another form used for Adding/Editing folder data will need to update it.
So, what is the best way to handle this: Currently the DT is created/maintained in the main form (FolderPad) that uses it. Would it be better to put the DT in a public Module for access, or allow the add/edit form to access the reference to it in FolderPad? Or is there a more accepted way to do something like this?
I have a program in VB.NET 2005. At some point I have to open an Access2003-Application for getting data in it. I do that by pretending my program is a human user and let it do all the work in Access as a human user would do. Filling Fields, pressing buttons etc. I use the Primary Interop Assemblies for that. So far so good. That code is in use for over half a year now. In the last week I got Office 2007 installed on my machine. Of course I tested the installed version of my program if everthing still works. Every test was succesfull. But if I do the same tests in Visual Studio it always crashes.
All I get is this Errormessage: {"Das COM-Objekt des Typs "Microsoft.Office.Interop.Access.FormClass" kann nicht in den Schnittstellentyp "Microsoft.Office.Interop.Access._Form3" umgewandelt werden. Dieser Vorgang konnte nicht durchgefhrt werden, da der QueryInterface-Aufruf an die COM-Komponente fr die Schnittstelle mit der IID "{66B22FB4-F70E-4F03-A00A-F76E9ADBBF10}" aufgrund des folgenden Fehlers nicht durchgefhrt werden konnte: Schnittstelle nicht untersttzt (Ausnahme von HRESULT: 0x80004002 (E_NOINTERFACE))."}
For all who can't read german:
"Microsoft.Office.Interop.Access.FormClass" can't be converted in to "Microsoft.Office.Interop.Access._Form3" ... Interface is not supported.
Code I use:
Dim access As Microsoft.Office.Interop.Access.Application = Nothing
.
.
.
access = New Microsoft.Office.Interop.Access.Application()
[CODE]...
The Error occurs when I try to access any property of "access.Forms("frmTest")"
I am trying to add data to a access datatable column I am using a richttextbox to fill in any data but when i save it to a column in a database and if there are more chars then 255 then i get an error (try to enter more then column lenght) anything under 255 is working fine the column in access = type of 'MEMO' so no limited to 255 it's the hystory to send that is giving me the problem
Dim history_to_send As String
Dim day_to_send As Date
Dim ID_to_send As Integer
[Code]....
I have a database in .ACCDB format with some tables.
I'm successfully loading it into an OleDbDataReader with the following code:
string connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;data source=C:\marcelo.accdb";
OleDbConnection conn = new OleDbConnection(connectionString);
[Code].....
I'd like to load the table "clientes" to a datatable instead. How should I do it ?
I have an Access Database "WPS" with a datasheet "CompartmentDescription" having "CompartmentName" as one of the columns. I want to use each element of the column. How do we retrieve the data Using "For Each" loop.
View 1 RepliesI've been perusing some hep forums and some help books but cant seem to get my head wrapped around this. My task is to read data from two text files and then load that data into an existing MS Access 2007 database. So here is what i'm trying to do:
Read data from first text file and for every line of data add data to a DataTable using CarID as my unique field. Read data from second text file and look for existing CarID in DataTable if exists update that row. If it doesnt exist add a new row. once im done push the contents of the DataTable to the database.
What i have so far:
Dim sSQL As String = "SELECT * FROM tblCars"
Dim da As New OleDb.OleDbDataAdapter(sSQL, conn)
Dim ds As New DataSet
[Code].....
In constructing my table i use "SELECT * FROM tblCars" but what if that table has millions of records already. Is that not a waste of resources? Should i be trying something different if i want to update with new records?
Once Im done with the first text file i then go to my next text file. Whats the best approach here: To First look for an existing record based on CarNum or to create a second table and then merge the two at the end?
Finally when the DataTable is done being populated and im pushing it to the database i want to make sure that if records already exist with three primary fields (DriveDate, DCode, and CarNum) that they get updated with new fields and if it doesn't exist then those records get appended. Is that possible with my process?
I've been browsing these forums for a day looking for the answer to this, so far nthing has fitted.I've got an access 2000-2003 database containing a whole pile of data for a VB coded application to use. One of the tables in the database needs to be able to be updated with data from the application.The new data is stored in the app as a datatable. I need to replace the original table in the Access file with the datatable in the App.
I'm changing as many as 60 values at a time, so defining these as parameters in an OleDbCommand would be impractical and frankly ridiculous.
Is it possible to edit/get data from a DataTable from another thread? On one form, I'm declaring a DataTable and loading it with some data. On the same form, I have a sub wich does some updates to the DataTable.
Now, I want to call that sub from another thread, but it seems like an impossible task... When I for example do a 'for each' in the sub wich updates the DataTable, it doesn't actually refer to the DataTable. All the rows and columns are not there.
I've been reading about some cross-threading and found some example where the objects invoke-property is used. But the DataTable does not have a invoke-property. So, how is it possible to do what I'm trying to do? I've been searching the forum/web for a while now, but maybe someone here can point me in the right direction?
I am working on a winform project like to dynamically create chexboxes from a datatable rows.
View 6 RepliesI'm trying to setup a form to search for data within an existing DataTable.
FilterColumnsComboBox.DataSource = WOTable.Columns?
FilterColumnsComboBox.DisplayMember = ???
FilterColumnsComboBox.ValueMember = ???
[Code]....
I could hard-code in the column names ("WO_Number",WO_CustID","CustLastName", etc...), but would prefer to pick this up dynamically (partly because I want to reuse this code later).
