I have connected a form to my database, which displays info when the form loads, butttt it displays them from load, which is not what I need, can someone tell me how to clear the form upon load so that none of the textbox fierlds have data within them? Untill I request them to.
View 4 RepliesI have a pile of checkboxes on one particular form and would like to clear them all at the form load rather that saying chk1.Checked = False for all of them.
Here is the code I was trying to use but 'checked' is not a member of Systems.Windows.Forms.Controls.[code]....
I have several forms that are "reused," or vistited more than once per each time in the whole program. In VB6, using Form.Show() would show the form in its original state (the state is was when created in the designer). After closing this form (Unload Me), showing it again would still show the form in its original state.
I am coding in VB.NET 2008, and noticed that when I reopen a form I had closed during a session using my program, the form is in the state it was when I closed it (labels and listboxes filled with data), and not in its original state. I currently have the Form.Closing event filled with code to clear all of the controls, but I think that there must be a better way to "clear" or "reset" the form.
When .Clear() is invoked, is the memory freed up that was allocated when all of the items were added? I need to load several lists of codes from a database depending on the import selected by the user. Each list of codes will be a List(Of String). My idea is that I will load only small strings into a List(Of String) along with a List(Of <class>) for the data I will be validating and manipulating. When I am done, I want all of the data from the Lists to be purged from memory. Will .Clear() take care of that or does the memory still remain allocated and have to be dumped by the OS once memory gets full? (And, incidentally, what causes the OS to decide which memory blocks to dump? FIFO concept?)
There are so many lists, I'm not sure if I just want them sitting in memory or not. Granted, the lists will just consist of a single string value for each code pulled from the database. So there won't be a ton of data, so maybe I could just load all the validation lists at the beginning of runtime and only worry about purging the data List since it will contain between 35-50 "fields" per record and there will be a couple thousand records each import that is run. I don't want my program to actually cause a hit in performance in the long run. I ultimately don't see a problem because I won't be running millions or even hundreds of thousands of records at once, but I just want to be sure.
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:ESHAN PROJECTUSMANasp.net_projectsHEALTHFOUNDATION PROJECTdatabasehvaccine.mdb")
View 2 Replieswhen i will enter form no. in the text box this should check the on the lost focus event either this form no. is already exsist or not.if exist show msgbox?
View 1 RepliesI got a DATASource connected, changed the table to details and draged it on to my form, but then it shows me the bindingnavigator at to of my form.
q1. how do i make it so every time this form opens it is like add new?
q2. how do make my own save button (don't want the binding navigator at top)
q3. in my form all my collums aper as textboxes how can i change it so there is a drop down menue that has forexaple 3 pre defined items that the user has to select on of.
How do I create a Login Verification routine (Login Form) in vb.net . i have an windows application with login form contain user name , password , ok button and cancel button .
as this one:
Imports System.Data.OleDb
Public Class LoginForm1
' OK button
[Code].....
but i want to run my application from desktop and will get confirmation if the user name and password correct by checking them in MS Access Database in the server.
so the the application in the desktop and the tabel of user name and password in the server.
How do i load the Main form of a WPF so that a seperate thread goes and gets data from the database while the form is in an apartmentstate? (drag-able / movable) I Know this is possible with opening a new window from your main form like this :
Private Sub openOrderWindow()
Dim OrderWindow As Orders = New Orders
OrderWindow.ShowDialog()
End Sub
[code]....
I've tried putting MyBase.ShowDialog() and .Show() and .9000+ other things The only benefit I've got out of using a seperate thread to load from the databse is i can see the screen right away (as oppose to it being a transparent box until it loads) but i cannot move it around or minimize it?is there any way to make it Movable while it loads?
I am having a function which populates a combobox (cmbProjtype) as shown below,
I am trying to clear cmbProjtype before I populate again to remove duplicates whenever the function is called, but the line of code added (highlighted) is not doing it.[code]....
For some unkown reason, my database tables will not drag and load onto a vb form, just get a circle with a slash in the middle. Trying to tanslate the table into textbox's.
View 4 RepliesI dont know how to dynamically populate a dataset based off the tables in an existing database.Once I can get the dataset to populate, I can then move forward with the next step of the project.
View 1 RepliesI'm viewing reports on a VB.net form using CrystalReportViewer. Once a report is opened, the Access database that is used within the report is locked (i.e., the Access MDB file can't be deleted). Even after the report is closed, the database stays locked until the VB.net app "ends". This is a problem because I want to be able to delete the MDB file at some point while running the app and can't. The VB.net app starts by opening a form named "Startup". No database connection occurs here. A button is pressed using this [code]I must not be properly closing the CrystalReportViewer or the Report form.How do I close the Crystal report and unlock/release the Access database?
View 2 RepliesI have connected a database query that I made using MS Access 2007 to my form in VB 2008. I know how to pull the fields onto the form and get the information to display on the form by clicking the binding navigator at the top of the form. My question is that is there a way that I could input the ID number in a textbox and click a button to display the rest of the field in some more textboxes
View 1 RepliesI 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.
On my program I am trying to make a ToolStripStatusLabel's text change to "connected" if connected to a network and if not connected to a network change the text to " Not Connected" then I don't know how to display a image if connected to a network or not connected. So if the computer is connected to a network I have a image that I would like to be displayed next to the ToolStripStatusLabel. And if not connected to a network, can the program display a different image? I tried this:
My.Computer.Network.IsAvailable=True(ToolStripStatusLabel2.Text "Connected")
My.Computer.Network.IsAvailable=False(ToolStripStatusLabel2.Text "Not Connected")
I am trying to find out if the connection of my sockets (TCPClient) is connected or not connected. I am using the following code:
[Code]...
Imports System.Data
Imports System.Data.OleDb
Public Class Form1
Dim con As OleDbConnection
Dim cmd As OleDbCommand
[CODE]...............
The insertion part of the form works great. But my problem is in the form load part......If i leave a field blank(Null),then perform Save operation,close the form after successful insertion and then reopen the form,then it retains the previous values during the form load......This is only in case where i leave a field blank in the previous data entry in the database.......But if i enter values in all fields then form load is working great.
I am trying to add a data source from a connected database but it doesnt seem to be working well.Initailly the table name was mispelled and there where fields missing. The table was modified to include the new fields and it was also renamed.The changes are reflected in the dbml file within the project, and the solution has been built with a sucessfull result.The problem is, when I try to add a new data object into my solution, the changes that were made to the database arnt reflected in this new data object.
View 3 Repliesi am using Visual Studio 2008 and VB.NET 2008 and SQL Server 2005 as the database. I just finished designing & writing codes for a customer information and , however after it has been connected to the database only one of the datetimepicker can be click, and the rest of the function including in the form are not working!it seem that the form stuck and NOT responding. i cant even close the form (X button), so i have to stop the process using compiler (visual studio 2008), however if i press the 'Delete' button before the 'Add' button, it will successfully delete the data.. but if i disconnected the form from the database, (disabled the form_load codes [put 'quote']) the both of datetimepicker will work and able to view the date interval (after pressing the 'Calculate Period' button) in addition how to make it appear automatically in screen without using the button? below are the code, I try to make some other form.. but it is still the same
Code:
Imports System.Data.SqlClient
Imports System
Imports System.Data[code].....
i am wondering if it is possible to get the source code for the following:
1. use vb.net code to set on/off primary key when connected to Access database
2. update a particular data.
for e.g: hostname: AES-19 *use source code to check data in Microsoft Access database
if hostname is new, insert into Access. if hostname already exist, update into Access
*so that i will not have duplicate data in Access.
[Code]...
I am designing a Point Of Sale system to be used by sales representatives. The sales rep should be able to place an order of a specific product on behalf of the customer. I have defined my relationships between the tables, Product, Order and Customer. When i try to save my orders i get an error that says "you cannot add or change a record becuase a rerlated record is required in table Product"
View 1 RepliesI have a thesis project. it is composed of a webpage created on php and a system using vb.net 2008. As of now , they are both connected to the same database. I am wondering if it is possible that if i packaged the system and live the website, will still be connected with one database?
View 1 RepliesI have a system that can add, edit, delete and search data that is in ms access. That ms access is connected to my vb 2008. I'm upgrading my system so that it can print the access file.
View 1 RepliesThis is the code that i did to fetch data from the database and filling it to the combobox dropdown list at the form load event:
[Code]....
How can I load a form and allow it to run it's code in the form load but keep it not visible. I want it to do what it needs to but but not display.
View 3 RepliesI have a connection to an access database, I have used the data sources tool provided because in this particular instance I don't want to do much with it other than display the records (which I can do) and edit them (which I'm haveing some trouble with).I have created a system whereby the database is connected to using the preset tools available like; BindingSource, TableAdapter, BindingNavigator etc.
I also have a button for edit. This doesn't work and I was wondering if anyone could help me with this? I can't really provide any code for this, because I didn't code the connection by hand and the code I have been attempting to use for editting the records in the database doesn't even sort of work.
how do i delete selected row from a datagrid connected to sql server database...?? Delete selected row and update database.
View 2 RepliesI am trying to develop an application using VS 2008 connected to MySQL database. Previously in vb6 i was using adodb and now when i googled and got a few sample projects done using VS2008 in which most of the module codes were OLEDB.....To which method should i stick to...?
View 2 RepliesWhen a vb project is connected to ms access(DB) whenever u make any changes in d db using addNew or insert or delete follwed by update command the changes are reflected in copy of original db in the debug folder of our project.in which updated values chnges with each run .. no changes are reflected in d original db.is dere any command to make dese changes permanent.
View 8 Replies