HI,
This question has been asked a lot on the web but all of them seems to be confused with windows forms and asp.net forms so I had to finally come here for answer.
I have a Main form (a window form) in VB.NET which has a Combo Box to display a list of countries. A sub form activated from a "Button" on the Main form allows users to add Countries to their list. But After Adding a new entry the Combo Box on the Main form does not show the update (while it is still open). I have to exit the main form and relaunch it to see the update.
The populate function in shown below. I call this method after adding new countries but still; not good. I have used Invalidate function of combo box but of no use as well.
Any Help is appreciated. Thanks
Public Sub PopulateCountry()
Dim rsLocal As New ADODB.Recordset
Try
Dim sSQLCommand As String
Me.CountryList.Items.Clear()
'get the list of countries from the local database
sSQLCommand = " SELECT * FROM CountryList order by CountryDesc"
rsLocal.Open(sSQLCommand, cnn, ADODB.CursorTypeEnum.adOpenStatic, ADODB.LockTypeEnum.adLockOptimistic)
'Display All the countries
While rsLocal.EOF = False
Dim Country As New modGV.cbItem
Country .ID = rsLocal.Fields("CountryID").Value
Country.name = rsLocal.Fields("Country Desc").Value.ToString.Trim
Me.CountryList.Items.Add(Country)
rsLocal.MoveNext()
End While
rsLocal.Close()
Catch ex As Exception
Debug.WriteLine("PopulateCountry: exception occurred " & ex.Description)
Finally
If rsLocal.State = ConnectionState.Open Then
rsLocal.Close()
End If
End Try
End Sub
Use object.refresh
http://www.devx.com/vb2themax/Tip/18646
Related
I am at my wits end. I have a VS 2022 VB Winforms application that was working perfectly fine up until last night. Now I am getting numerous errors, most of which state "Value of type 'ComboBox()' cannot be converted to 'ComboBox()' because 'ComboBox' is not derived from 'ComboBox'". Another error staes "'DropDownWidth' is not a member of 'ComboBox'". The only thing I noticed is that the solution platform now reads "Any CPU" instead of "x64". I did not change any code that has to do with the combobox routines so the errors seemed to have come out of nowhere and the x64 solution platform is no longer an option. Any ideas? I included my code where the errors started popping up.
Public Class GlobalVar
Public Shared cmbBurgType() As ComboBox = {frmSearchNOC.cmbSearchBurgType, frmAddEntry.cmbAddBurgType}
Public Shared cmbSex() As ComboBox = {frmSearchNOC.cmbSearchSex, frmAddEntry.cmbAddSex}
Public Shared cmbRace() As ComboBox = {frmSearchNOC.cmbSearchRace, frmAddEntry.cmbAddRace}
Public Shared cmbPrefix() As ComboBox = {frmSearchNOC.cmbSearchHomeStreetPrefix, frmAddEntry.cmbAddHAddressPrefix}
Public Shared cmbSuffix() As ComboBox = {frmSearchNOC.cmbSearchHomeStreetSuffix, frmAddEntry.cmbAddHAddressSuffix}
Public Shared cmbState() As ComboBox = {frmSearchNOC.cmbSearchHomeState, frmAddEntry.cmbAddHAddressState}
Public Shared cmbPrecinct() As ComboBox = {frmSearchNOC.cmbSearchHomePrecinct, frmAddEntry.cmbAddHAddressPrecinct}
Public Shared cmbTattooLoc() As ComboBox = {frmSearchNOC.cmbSearchTattooLocation, frmAddEntry.cmbAddTattoo}
End Class
Public Sub LoadPresetDBDataCombobox(tableName As String, colName As String, objArray() As ComboBox)
Dim longestEntry As String = ""
Dim curText As String = ""
Dim sqliteReader As SQLiteDataReader
Dim sqliteReadCmd As SQLiteCommand
'clear combobox items
For Each curBox As ComboBox In objArray
curBox.Items.Clear()
Next
OpenDBConn() 'opens the database connection
sqliteReadCmd = GlobalVar.dbConn.CreateCommand()
sqliteReadCmd.CommandText = "Select " & colName & " FROM " & tableName
sqliteReader = sqliteReadCmd.ExecuteReader()
sqliteReadCmd.Dispose() 'disposes read command after it is used
'iterate through table
Using sqliteReader
While sqliteReader.Read
curText = sqliteReader.GetString(colName) 'gets the current table value for the selcted column
'places value into each combobox in array
For Each curBox As ComboBox In objArray
curBox.Items.Add(curText)
Next
'determines the length of the longest string to size to properly dize the drop down width to fit text
If (curText.Length > longestEntry.Length) Then
longestEntry = curText
End If
End While
'assigns the dropdownwidth based on an everage character width of 6 pixels
For Each curBox As ComboBox In objArray
curBox.DropDownWidth = ((longestEntry.Length * 7) + 10)
Next
sqliteReader.Close() 'close object
longestEntry = ""
End Using
CloseDBConn() 'closes the database connection
End Sub
Private Sub OpenChildForm(childForm As Form, formIndex As Integer)
If (currentChildForm IsNot Nothing) Then
currentChildForm.SendToBack()
End If
currentChildForm = childForm 'assigns passed in form as current form
childForm.TopLevel = False 'indicated the form is not top level because the main form is top level
childForm.Dock = DockStyle.Fill 'docks form to fill main form's panel
pnlMain.Controls.Add(childForm) 'adds form to the main panel on the main form
pnlMain.Tag = childForm 'associate form to main panel on main form
childForm.BringToFront() 'brings the related form to the front
childForm.Show()
Select Case formIndex
Case 0 'search noc form
'reloads various data from db into comboboxes in case items were added while on another tab
LoadPresetDBDataCombobox("BurgType", "typeName", GlobalVar.cmbBurgType) 'tattoo location
LoadPresetDBDataCombobox("Sex", "sexName", GlobalVar.cmbSex) 'sex
LoadPresetDBDataCombobox("Race", "raceName", GlobalVar.cmbRace) 'race
LoadPresetDBDataCombobox("StreetPrefix", "prefixName", GlobalVar.cmbPrefix) 'street prefix
LoadPresetDBDataCombobox("StreetSuffix", "suffixName", GlobalVar.cmbSuffix) 'street suffix
LoadPresetDBDataCombobox("State", "stateName", GlobalVar.cmbState) 'state
LoadPresetDBDataCombobox("Precinct", "precinctName", GlobalVar.cmbPrecinct) 'home precinct
LoadPresetDBDataCombobox("BodyPart", "bodyPartName", GlobalVar.cmbTattooLoc) 'tattoo location
Case 1 'browse results form
Case 2 'add entry form
'reloads various data from db into comboboxes in case items were added while on another tab
LoadPresetDBDataCombobox("BurgType", "typeName", GlobalVar.cmbBurgType) 'tattoo location
LoadPresetDBDataCombobox("Sex", "sexName", GlobalVar.cmbSex) 'sex
LoadPresetDBDataCombobox("Race", "raceName", GlobalVar.cmbRace) 'race
LoadPresetDBDataCombobox("StreetPrefix", "prefixName", GlobalVar.cmbPrefix) 'street prefix
LoadPresetDBDataCombobox("StreetSuffix", "suffixName", GlobalVar.cmbSuffix) 'street suffix
LoadPresetDBDataCombobox("State", "stateName", GlobalVar.cmbState) 'state
LoadPresetDBDataCombobox("Precinct", "precinctName", GlobalVar.cmbPrecinct) 'home precinct
LoadPresetDBDataCombobox("BodyPart", "bodyPartName", GlobalVar.cmbTattooLoc) 'tattoo location
Case 3'user settings form
Case 4 'administrator form
End Select
End Sub
Above, the errors come into play with all the GlobalVar parameters as well as the dropdownwidth call:
LoadPresetDBDataCombobox("StreetPrefix", "prefixName", GlobalVar.cmbPrefix)
curBox.DropDownWidth = ((longestEntry.Length * 7) + 10)
I tried updating VS 2022 and then reinstalled it. Neither of which worked, obviously, considering I'm asking this question. It's probably something simple and stupid but I am fried and could use some help.
Thanks to anyone who spent time reading my question. I have no idea how or when the following import got added to one of my routines but I commented it out and all the errors went away:
Imports System.Windows.Controls
I noticed it when I was copying code from my broken project to a new project to see when the errors start popping up. My best guess is that it was importing a combobox control that was different from the combobox I was trying to pass into the routine, but any comments that explain the reason are appreciated.
all
I am working on a project with vb.net and MySQL database.
Now for taking information I have added few checkboxes, and in case if user selects a checkbox named other I want a window to appear and it should have a text box and when user enters the text at that box, the details should be stored in db.
As you haven't provided much information I may can't answer exactly your question but check if this can help.
First Add LINQ to SQL (.dbml File) - Let's name it as XYZ and Dataset (.xsd File) - let's name this as XYZ too, to your project and then drag and drop your database table in both the files and save all.
Now going into your form which contains the check box you mentioned.
Add this code to you checkbox click_event.
If checkbox1.checked = True Then
Dim insertValue As String = ""
insertValue = InputBox("Enter text to insert", YourTitle, "")
If inserValue <> "" Then
Dim db as New XYZDataContext
Dim NewRec As New YourTableName With {.ColumnName = insertValue}
db.YourTableName.InsertOnSubmit(NewRec)
db.SubmitChanges()
Msgbox("Value added!")
End If
checkbox1.checked = False
End If
create your window in the designer and give it a name like someWindow. then in your code open the window from the click event of your checkbox. when you close the window don't dispose it. just hide it me.hide so when you window closes you can retrieve the data from your textbox.
Sub Test ()
Dim wd_SomeInfo as new someWindow
wd_SomeInfo.showdialog()
Dim result As String = wd_SomeInfo.txt_sometextbox.text
If result = "" Then cancel....
End Sub
I have tried to find an answer to this already, but cannot find one that answers this question.
I have a Master Form which contains two panels. In the master Form I am trying to write a subroutine to handle the loading of a form into one of the panels.
One panel always contains the same form and the code which works for this is:
'Configure Toolbar Import
Dim toolbarHandler As _pnl_header = New _pnl_header()
toolbarHandler.Size = pnlHeader.Size
toolbarHandler.TopLevel = False
pnlHeader.Controls.Add(toolbarHandler)
toolbarHandler.Show()
The panel successfully shows the form _pnl_header as expected.
The second panel will change the displayed form depending on user input, so rather than having to write the above code for every eventuality i would like one Public Sub to handle them all...
I've started writing a sub along the lines of:
Public Sub LoadContentPanel(WhichForm As Form)
Try
Dim contentHandler As WhichForm = New WhichForm()
contentHandler.Size = pnlContent.Size
contentHandler.TopLevel = False
pnlContent.Controls.Add(contentHandler)
contentHandler.Show()
Catch ex As Exception
MsgBox("Unable to Handle Content Panel Change. Error: " & ex.Message, vbOKOnly + vbCritical, "Load Error")
End Try
End Sub
However this fails as 'WhichForm' is not defined - how is best to correct this? or is there a better alternative?
Thanks
Without going into what you are doing I can explain where the error comes from.
Here you declare argument variable WhichForm of type Form
Public Sub LoadContentPanel(WhichForm As Form)
. . . . .
Code is incorrect in the next declaration line. WhichForm is a variable and not a type. Hence
Dim contentHandler As WhichForm = New WhichForm()
is invalid at As WhichForm. Because after As you need a type name. If you did
Dim contentHandler As Form = New Form()
it would work.
It seems that all you need to do is remove Dim contentHandler As WhichForm... and rename argument WhichForm to contentHandler.
I would like a message box to pop-up at the start of the program asking what the customers name is. I then want this name to be displayed in a label that i have already created.
I went to application events and entered the code below after finding a few helpful tips around the internet. I get a message box allowing me to enter the customers name, so that bit works fine. The problem comes when I try to change the label. It says that 'label4' is not declared. I'm guessing that the application events section is a completely different section from the other forms.
If anyone could explain how I would go about doing this correctly and also explain the difference between so I can learn from this that would be great.
Dim message, title, defaultValue, myvalue As String
' Set prompt.
message = "Please Enter The Customers Name"
' Set title.
title = "New Customer"
' Set default value.
defaultValue = ""
' Display message, title, and default value.
myValue = InputBox(message, title, defaultValue)
label4.text = myvalue
The controls of a form a defined locally to that form, i.e. they are private members of that form and cannot be accessed from outside. Now it depends how your code is organized. If you are calling the InputBox before opening the main form then you need a way to pass the customer name to the main form. You can do that in the constructor the main form.
' In the main form
Public Sub New(ByVal customerName As String)
InitializeComponent() ' This call is required by the Windows Form Designer.
label4.Text = customerName
End Sub
Then you can create the main form like this (see also How to find the main() entry point in a VB.Net winforms app?)
Public Sub Main()
Application.EnableVisualStyles()
Application.SetCompatibleTextRenderingDefault(False)
...
myValue = InputBox(message, title, defaultValue)
Dim frm As Form1 = New Form1(myValue)
' Starts the application.
Application.Run(frm)
End Sub
Please forgive me, it has been some time since I've used VB.Net so this may be easy.
I have a simple login form with a text box, combobox and a button. The combobox is binded to a SQL database and displays the user names from Users table. The idea is that you select a name, type in a password, and you logon to a new form (This part works Great!). If you type a wrong password, the form pops up a message that says "invalid." For some reason at this stage, the combobox goes blank. The drop down now has empty spaces where names once were. Typing in a name with a password here results in object reference errors. I have tried everything to get the combo box to reset and searched the web but nothing works!!!
(I know this is not a secure login, this is just an easy example of binding data to a combo box and checking it against SQL table). Thanks for your help!
enter code here
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles BTN_Logon.Click
Try
Dim STR_User As String = Users_nameComboBox.SelectedValue
Dim STR_Pwd As String = TB_Pwd.Text
STR_User = STR_User.Trim
'MessageBox.Show(STR_User & "|" & STR_Pwd)'Used to verify this stage works
Dim numRecords As Int16 = UsersTableAdapter.FillByLogin(Me.Login_testDataSet.users, STR_User, STR_Pwd)
'MessageBox.Show(numRecords) 'Used to verify this stage works
If (numRecords > 0) Then
Dim DB_User As String = Me.Login_testDataSet.users(0).users_name.Trim
Dim DB_Pwd As String = Me.Login_testDataSet.users(0).users_pwd.Trim
'MessageBox.Show(DB_User & "|" & DB_Pwd)'Used to verify this stage works
If DB_User.Equals(STR_User) And DB_Pwd.Equals(STR_Pwd) Then
'User is authenticated for application
'This section works (removed to cleanup code)
Else
MessageBox.Show("ERROR" & STR_User & "|" & STR_Pwd) 'Shows that this stage works
'Need to figure out why combobox doesn't refill, using restart for now
'Application.Restart()
End If
End If
MessageBox.Show("ERROR" & STR_User & "|" & STR_Pwd) 'Shows that this stage works
'Need to figure out why combobox doesn't refill, using restart for now
'Application.Restart()
Catch ex As Exception
MessageBox.Show(ex.Message)
'Need to figure out why combobox doesn't refill, using restart for now
'Application.Restart()
End Try
End Sub
InitializeComponent
'Users_nameComboBox
Me.Users_nameComboBox.DataBindings.Add(New System.Windows.Forms.Binding("Text",
Me.UsersBindingSource, "users_name", True))
Me.Users_nameComboBox.DataBindings.Add(New System.Windows.Forms.Binding("SelectedValue", Me.UsersBindingSource, "users_name", True))
Me.Users_nameComboBox.DataSource = Me.UsersBindingSource
Me.Users_nameComboBox.DisplayMember = "users_name"
Me.Users_nameComboBox.Name = "Users_nameComboBox"
Me.Users_nameComboBox.ValueMember = "users_name"