Winforms Checkbox Databinding - Create A New Record (without Having Saved The Previous)
Apr 17, 2010
In a winforms application (VB, VS2008 SP1) i bound a checkbox field to a SQL Server 2005 BIT field. The databinding itself seems to work, there is this litte problem: user creates a new record and checks the checkbox, then the user decides to create a new record (without having saved the previous, so there are 2 new records to be submitted) and checks also the second.
I am a freshman by using vb and I had search several website to learn the method to display the previous saved data in a label but none of it is related to my problem.
This code i had use for create a field in DB Access 2003:
SQL = "ALTER TABLE plano_contas ADD declperiodica06A char(40) WITH COMPRESSION NULL)" Dim command1 As New OleDb.OleDbCommand(SQL, con1) con1.Open() command1.ExecuteNonQuery() con1.Close()
like you see the code create a Text field with 40 lenght...Well the problem is:When i save a new record the record it's save in this mode: "100......... .........................." - the points means spaces and should be:"100"After try a lot of things i'm without more solutions in find why this happen!
How to bind data from database to combobox of winform in VB.NET .
Database : MSSQL server managemant studio Front End : Vb.net 2008
In the combo box binding,i need to put "Product_gid" in index and "Product_Name" in the value of combo box.How do i add an item "Select" in the 0'th position of Combo box,So that every time i opened the list of combo box,the 1st item will be "Select",other from database.
|-Table 1 |--PK IDT1 |--Name field |-Table 2 |--PK ID |--FK IDT1 |--Name field
I want to bind Table 1 to combobox1 and Table 2 to combobox2 so as when someone selects a value in combobox1, combobox2 populates with only the rows with the FK IDT1 value from combobox1. Is this possible with databinding or do I have to code it?
I'm trying to bind CheckedListbox's Cheched items to Combobox my code is given below
Private Sub chklColumns_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chklColumns.SelectedIndexChanged cmbSort.DataSource = chklColumns.CheckedItems End Sub
whenever I check an item first time it loads one item to the Combobox, but when I select second item still I have single item in the Combo...
In WPF I've generally done databinding using an ObservableCollection and edits to the xaml. Is there a way to quickly do it, like the above? Edit: This seems to be the simplest/quickest thing I can come up with, anything inherently wrong with it?
If I turn off automatic updating of a binding data source by setting DataSourceUpdateMode = Never and then use a button to update the whole lot (using binding.WriteValue), a problem occurs - Namely, only the first bound control's data source is updated. All other controls are reset back to the original values.This is because when the current object changes (as happens after the above WriteValue), if ControlUpdateMode = OnPropertyChange, then all the other controls re-read in the value from the data source.
One way is to derive a class from BindingSource and add a WriteAllValues method.This method does the following:
(1) For each Binding, save the ControlUpdateMode
(2) For each Binding, set ControlUpdateMode = Never
(3) For each Binding, call the WriteValue Method
(4) For each Binding, reset ControlUpdateMode to the saved value
(5) For each Binding, if ControlUpdateMode = OnPropertyChange, call the ReadValue method.
If working with your own classes, would implementing IEditableObject resolve the issue?In another control I'm working on, I implement my own binding. The way I get around the issue in that is with the following code. (I've put in the bare minimum, I hope you can follow it!):
Private Shared ControlDoingExplicitUpdate As MyCustomControl = Nothing Private Sub UpdateDataSourceFromControl(ByVal item As Object, ByVal propertyName As String, ByVal value As Object) Dim p As PropertyDescriptor = Me.props(propertyName)
[code]....
So, when UpdateDataSourceFromControl is called, all the CurrentItemChanged events will be called for all other controls in the same BindingSource. However, because ControlDoingExplicitUpdate is set, they will not re-read in the value from the data source unless they happen to be the control that did the updating.ControlDoingExplicitUpdate is set to Nothing after all these events have completed, so that normal service resumes.
I have a custom control with a bindable property:-
Private _Value As Object <Bindable(True), ... > _ Public Property Value() As Object Get
[code]....
Also, here, I'm adding a handler to the DataBindings.CollectionChanged event.This is the second place that I retrieve the type:-
Private Sub DataBindings_CollectionChanged(ByVal sender As Object, ByVal e As System.ComponentModel.CollectionChangeEventArgs) If e.Action = CollectionChangeAction.Add Then Dim b As Binding = DirectCast(e.Element, Binding)
[code]....
I need the first place, because the BindingContextChanged event is not fired until some time after InitializeComponent.The second place is needed if the binding field is programatically changed.Am I handling the correct events here, or is there a cleaner way to do it?
Note: My GetValueType method uses the CurrencyManager.GetItemProperties....etc, to retrieve the type.
I made a window for the purpose of managing "profile" records
while the navigation and updating is working
i cannot seem to get insertion working, as well[code]...
when i press add, i get a new empty record, when i fill it in, i see that the collection sees it, as there is an onform listbox showing the profiles, and it gets listed there, so its actually attached to the list, but the savechanges command does not insert it into the db
there may be some validation errors upon insert, but then i would get some indication, right? now its just silently failing. as if i never tied to commit changes
I have the following code which is linked to a previous and next button, however I need to have a loop so that if a next button doesn't exist then it does nothing as it currently ends the program with an error when it gets to the last record and I click next or previous.
I have a LINQ to SQL DataContext with all my tables and all my stored procedures in it. Let me first start off by saying that we are upgrading our project from an access project to a WPF project. So in the Access project you could set a forms datasource to a stored procedure and edit and add new information. So in my WPF project on the page load I call my stored procedure to return an ISingleResult and then call a function to set the binding on every single textbox on the form. One is there an easier way to do this and two what if I want to add a new record since the textbox's are binded to an ISingleResult?
On form1 I have a InputDialog (Created by code.) on the Dialog there is a InputTextBox that is bound to MyBindingSource. When the Enter Key is pressed I need Label1 to replace the dialog while saving the entry to the DataBase and then display that saved record.
I know its .net but i am still using ADODB this is just a sample table, not really what i am doing..I want to take a look at a bunch of records until the customer changes. then i want to have the previous recordset data displayed or passed off to another function how do i set RS2=RS but when i "movenext" RS RS2 still holds the previous record data? [code]
I have following codes on lostfocus of textbox1.text to search values. It works fine but how to navigate database. I mean what codes should I use for Next Record and Previous Record Buttons. My SQL database name is accounts and table name is employees
str = "select * from employees where sno =" & Val(Me.TextBox1.Text) dt = GetTable(str) If (dt.Rows.Count >= 1) Then Me.TextBox2.Text = dt.Rows(0)("name") Me.TextBox3.Text = dt.Rows(0)("city") Me.TextBox4.Text = dt.Rows(0)("phone") [Code] .....on
I am attempting to create a program which saves customer information for a business e.g first name, last name, address etc. but i am having trouble coding the save , new, print, next/previous record buttons.
i have a sql table which has 2 fields number & name
1 abc 2 xyz
Situation is that the app finds out max of number and increments it by 1 to get new number.The problem is when two users enter some record sometimes two records get saved on same number.
I am designing programe that diplay student record from database to some asp.net control like Label and Dropdown control and nagigate the record using Next and previous button I want to view One Record at Once at a page Bellow is my Html Page
I need to assign an Age to the elements in an array. If a value in this array remained the same in the same position in the array then multiply by a big factor and send to the bottom of the array.
I have a question, I can't really find the answer...Basically I have 2 FormsIn form number 1 I have 2 pictureboxes. I want to create a checkbox in form2 that says if checkbox 1 is checked then show picture 1 in form 1
I'm trying to create a random name generator, and in order to store all the names I'm using an SQL database. I've got the database set up (simple version just until I get it working) and here's basically what I want the program to do. My database consists of three main fields: Name, Gender, and Origin (along with corresponding ID's). I want the user to be able to use a drop down combo box to select the gender (m or f) and the origin (i.e. English, German, Chinese, etc.), have the program filter out any data not within these parameters, randomly choose one of the remaining names, and display it on the form in a label. I'm not quite sure how to get the combo boxes linked to the data set so that, when running, the chosen item filters the data.
I have a problem with my program, and it's really bad because I need to burn it to disk within 12 hours and I can't get it to work: If I create a record, add information to it and click on Next Record, the ID, Status and Notes boxes content will change but the rest of the controls contents are carried over to the next record and I don't know why or how. It was working perfectly but now it stopped and I never done anything.
WHat i have done is Create a SQL string that takes the ID 544 and searches through database. If a match is found the the same as the LOCATION name on another Table then it takes the LOCATIONID (it will be the ID, but not at the moment) and puts it into a listview along with its IN STOCK.THe location Table looks like so:
IDLocationName 3MainWarehouse 4StrongRoom
[code]....
Running through this code. The system checks the "NewLocation" checkbox ONLY!
The ContextMenuStrip tied to the ListView control. However, the right click option (edit)appear where ever i click on the ListView area, this gives me exceptional error because the implementation of edit can only cope with a selected row. I only want it to appear when on a selected row (blue highlighted row). How can i do it?
I have used VB (versions 2 - 6) through many years; however, I am crash-course training myself into the VB2008 / VB2010 world kicking a screaming. I would like suggestions as to what SQL database access method should I focus more on in my learning process without making me feel that I'm a million years behind. I know I have WinForms where I can create a datasourse and drag / drop fields or tables on a form to create a grid (not really what I'm looking for).
My trouble isn't so much designing the form but in how I access the database. Theres XML, LINQ to SQL, ADO.NET, and many other methods. Not only do I need to grasp these methods quickly but I also need to know what type of projects I should create. What I mean is...I was thinking that I would design a WinForm app; however, I see that there are WPF apps and others to chose from. This is getting deep. I know it depends on the project that I'm working on. My plans are to write an app based off of either an SQL Express 2008 or SQL Server 2008 database. This first app will be standalone for now but may later become multi-user. I know I'm far behind on my learning curve coming from VB6. I have read a bit on VB2005 / 2008 / 2010. I own both VB2008 and VB2010. I use VB2008 at work. I know ADO.NET is still alive but by what I read online, it's a dying method and is only kept for backward compatibility. XML and LINQ to SQL and other methods are all pretty new to me.