I have declared a dataset (let's call it 'Fred') as public in a VARs module. In the main form in a sub routine called at the start of the project I connect to an Excel spreadsheet and read it into the 'Fred' dataset into one table (called 'Table') I then bind the dataset table to a datagridview and I can see the spreadsheet. Which is very nice :-)
Having loaded the dataset I want to be able to get some values so I created a button and used the following
msg = Fred.Tables("Table").Rows(0).Item("Name")
I think this should get the value in the first row and in the column called 'Name' in the table called 'Table'
But I get an error when I click the button 'Object reference not set to an instance of an object' which I think means I need to use the 'New' keyword...
So I added to the button
Dim Fred = New DataSet
But I get the same error.
Now I have to admit that I've never really got my head around how to use the 'New' keyword and would have hoped to be able to get data from a dataset through my entire project - especially as I've declared it as 'Public'. Surely if I use 'New' all over the place then I create new datasets
I'm working on my first real vb.net project, after years of using VB6. I'm using Visual Studio 2008. While I've been learning, I've added lots of DataSets to my project and then realised I'd got something wrong, so I've added, and begun to use, a new one. Trouble is, I'm not sure now which ones are used and which aren't.
How can I identify which DataSets aren't being used, and then what is the best way to remove them cleanly? Or should I stop worrying about tidying up and get on with the development work? ;)
I have a program I've been working on for some time now and I'd like to try to streamline it somewhat. I have a main menu form that has a split panel, in the left panel is a treeview that displays forms you can open and when one is selected, it opens in a child window in the right panel. Each time I open form I called DWNForm, it does a series of dataset loads which are the populating items for a series of listviews.
What I would like to do is have these datasets load once during the mainMenu load and then have the DWNForm be able to access the datasets once it is called from the treeview selection.
I have a dilemma. The program I"m trying to complete is one VB project with three (3) forms. The first form will act as a menu dialog box. The other two forms will have a dataset (database) on each form. The first form will have a button when clicked it will pull up form 2 and the second button when clicked will bring up form 3. What I add the dataset to form 2 everything is fine. I can see my tableadapter, dataset and so on. Now, when I add the second dataset (database) to form 3, I loose my, dataset and so on. It doesn't appear on any of the two forms (in designer)tableadapter.
Whilst playing around with DataGridViews in VS I've accumalated quite a few TestDataSets within my project.
Can someone please tell me the correct way of removing these cleanly? At the moment I've been Right Clicking a DataSet (from within Solution Explorer) and either clicking 'Delete' or 'Exclude From Project'
Doing this throws up Errors in the Error list such as;
TestDataSet is not defined TestDataSetTableAdapters is not defined TestDataSet is not defined TestDatasetTableAdapters is not defined
I then double click each error in turn which takes me to the actual code with the error and delete this.
I have quite a lot of TestDataSets and I'm hoping there is another way to do this much cleaner.
How can I change my connection configuration of my datasets and project. I mean, my datasets are not hard coded, I am using dataset wizard. Now, I have to change the computer name to IP.
I am worried that it could give a destruction to my project. How could I change it easily and safe?
I have a number of projects in a solution and want to be able to access forms in all of the projects from a form in the main project. I thought of doing this to keep each segment of the solution manageble. If something goes seriously wrong in one of the projects it is easier to fix that starting from scratch with the whole solution.I have found numerous suggestions on this topic from "It cannot be done" to suggestions that do not work. The closest that I have come and still does not work is as follows:
Imports VAT_List.Form1 'This is Form1 in Project 2 Public Class Form1 ' This is Form1 in the Main Project Private Sub ListsToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListsToolStripMenuItem.Click 'Imports VAT_List.Form1
how to access a form in a different project but within the same solution? Say I click a button on one form to display another form which is a part of the same solution but resides in a different project.
I have coded two seperate VB.net windows forms application as two seperate projects in seperate solutions. I now want to combine one project called "Reporting" into the other project called "AnalysisApp" and be able to call the Reporting apps main form.The Reporting app utilies a whole load of controls from DevExpress which are not included in the "AnalysisApp" I have added references in "AnalysisApp" to the DevEpress controls and also to the Reporting app, as well as combining the Reporting app into the same solution, but when I build the "AnalysisApp" it fails saying that it cannot find the DevExpress DLLs
I have created a project, and with form3, created a class for datagridview called MyDtGrd.nd when I created a form4 I used that same MyDtGrd. When I used before to publish the program no problem.But after publishing When I tried to make changes, giving error like"The variable MyDtGrd is either undeclared or was never assigned"Is there any technique to access the same class oject to use in other forms?
I developed a project in VB.NET..In this project I want to use data from MySQL that is resides in my WEB Server.I can communicate with the MySQL server of my localhost but can not communicate with the WEB Server.In my CPanel I added Host from the Remote Database Access..But I can't communicate with WEB MySQL Server.
I have a "windows form" user control--that is, not on a web page etc. This user control has a form within the user control project. However, code from within the user control can't 'see' the form even though it is a public class---I don't understand why this is the case.
So how can I access the controls (a couple of radio buttons) on the form from code within the user control? I tried creating public properties on the form to return the state of the radiobuttons, but this still doesn't work. I get a "Reference to a non-shared member requires an object reference." error
Should I not be able to see the form since it is a public class?
I am trying to access the types file from the project directory for the web root directory. Currently it only accesses it from the C:/, how can I have it access this file from the web root. I would like the file to be in the project folder as types.txt.
For reasons that are beyond my control, I have three Projects. Projects A and B reference project C. Project A references project B so that it can open a large form in project B. I now need to open that large form from project C, but VB won't allow me to add a reference from C to B because that would create a circular dependency. I found a way around it, though. I created a Timer in A, and when I opened C from A, I passed in that timer. When the user performs a certain action, I enable the Timer from A, and this causes C to open B for me.
I'm trying to work with an ODBC driver for Interbase in VS2008 (vb). I succesfully inserted the data tables I want to use in the project datasource. Then I want to add some rows in one of the tables of the datasource. I used myDataSet.addTABLENAMErow(field1, field2, ...).The compiler gives me no error, but when I open the database with InterbaseConsole, the line I've add is not there. Do I do something wrong? Must I open/save the database (how do I do so). I've tried meDataSet.AcceptChanges whitout result.I'm not used to work with Datasets and tables...
I have a project that I have created, it something like a contact database.It is complete with its own sql server database, and controls and forms.I kinda of understand that I can include this project into another project.This is the tricky part,Can I include my contact project into another project and add more items to the database and forms in a new project?What I'm after is like using classes.My contact database would be like the base class, and the new project would be adding more features to that project.
I'm trying to combine two datasets, each with 1 datatable and each having the same schemas. Datatable 1 would have a list of records. Datatable two may, or may no, have some or all of the records from table 1 plus more records. I would like to remove all the records from table 2 that are present in table 1.
This is what I got so far: For Each table1 As DataTable In ds.Tables For Each row1 As DataRow In ds.Tables(0).Rows ds.Tables(0).PrimaryKey = New DataColumn() {ds.Tables(0).Columns(0)} 'Where 0 is the index of the column that's your key row2 = ds2.Tables(0).Rows.Find(row1("ID")) 'if its found, delete it Next Next
First Dataset Dim sql As String sql = "SELECT payment.Debtor, SUM(Value_invoice) AS before_this_month,debtor.nama FROM Payment INNER JOIN dbo.debtor ON Payment.Debtor = debtor.debtor" & _
[code]....
Now i just want to either inner join or left join PaymentBeforeThisMonth and PaymentThisMonth into another dataset?
I have a dataset that contains only employee ID's. I need to loop through that dataset and for each employee ID I need to loop through several other datasets and pull data. I need help with this looping syntax. Here is a sample of some code that I am receiving an error with:
Dim EMPID as Integer Dim CommandEmpid As New OleDb.OleDbCommand Dim EmpidDS As New DataSet
I have a form that needs to load data for 20 different combo boxes - the data is always the same. To get the combo boxes to function properly i need to create a separate dataset for each combo box. Doing this when the form loads takes it about 7 seconds each time a search result is double clicked and the form pops up displaying the correct data. The form is bound to the main table. Is there a way to store these data sets in memory somewhere so the user can close the form but still have them loaded? I can put this code behind the login form and it works until the form is closed, then the combo's no longer load.[code]
i want to check if datasets have changes and after that use msgbox (vbYesNoCancel) when program closes ,when i wrote this code it had error "Operator 'Or' is not defined for types 'System.Data.dataset' and Boolean"..[code]
I want to use my main dataset (dbds) on a second form. It's simple, on my main form, the user clicks a button, opens a new form, they enter an item number and I want to find that row, and change a value in another column of that same row, and have that be in effect onthe main dataset to send back to the database.[code]...
What is the best way for me to have several datasets ?i've thought about creating a routine for creating datasets with a number in their names, each one with the desired data, but that's not very intelligent (although might work)i'd like to create what would be like an "ARRAY OF DATASETS"
[Code]...
(obs, i've done the same code loading one XML to one dataset and it works perfectly, i've gone back and forth more than one time to assure that it isn't just a logical mistake, it's syntax and lack of programming knowlegde.
I need to very quickly write an exe system on a laptop where when the laptops are connected to the network they read a database table and store the data locally, so staff can use the laptop while they roam.The laptops have quite small capacity and the company would prefer not to use SQL Express or Access.
My question is, can the data initially be downloaded into the exe application via a dataadapter and dataset, and will that dataset the retain the downloaded data, or will I need to ensure the dataset is written to an XML file and then loaded/unloaded each time the laptop application is started while the staff are travelling ?
What I'm looking for are videos in vb.net for console application that will show me how to use DataSets and TableAdapters step by step. Please provide links
I'm using the MYSQL .NET connector with an adapter to fill a dataset from a SELECT statement. Between different SELECT statements I use the DataSet.Clear() function. The Getxml shows me that the dataset is empty, however when cycling through the Table's columns, I have all the columns from all the tables used in prior SELECT statements.
How do I go about that without Dimming new Datasets for each table?
