I have a bunch os items in lst1 which I want to put into lst2 but without repeating them on each ListBox.
Interface I'm using:
This is working, but you may need it to understand my doubt.
Dim dtTa_Enc As DataTable = New DataTable("Ta_Enc")
Dim dsTa As DataSet = New DataSet("Ta_E")
Dim adapter As New MySqlDataAdapter
Dim ds As DataSet = New DataSet
adapter.SelectCommand = New MySqlCommand
adapter.SelectCommand.Connection = connection
adapter.SelectCommand.CommandText = query
connection.Open()
adapter.Fill(ds, "tables")
connection.Close()
lst1.DataSource = ds.Tables("tables")
lst1.DisplayMember = "name"
lst1.ValueMember = "codta"
dtTa_Enc.Columns.Add("codta")
dtTa_Enc.Columns.Add("name")
dsTa.Tables.Add(dtTa_Enc)
lst2.DataSource = dsTa.Tables("Tables")
lst2.DisplayMember = "name"
lst2.ValueMember = "codta"
dtTa_Enc.Rows.Add(lst1.ValueMember, lst1.GetItemText(lst1.SelectedItem))
Doubt:
Now, The user presses a button to add his selected item of lst1 to lst2. Easy! However, what if he tries to add the same item. Can VB.Net stop him from doing it?
If not dtTa_Enc.find("codTa = " + lst1.valuemember) Then
dtTa_Enc.Rows.Add(lstTabelas.ValueMember, lstTabelas.GetItemText(lstTabelas.SelectedItem))
End If
Under the Add event handler, you could place some logic at the begining to prevent adding the repeated item.
Dim lst1Selected As String = CType(lst1.SelectedItem, DataRowView)("name").ToString
Dim flag As Integer = 0
For Each item As Object In lst2.Items
Dim istr As String = CType(item, DataRowView)("name").ToString
If istr = lst1Selected Then
flag = 1
Exit For
End If
Next
If flag = 1 Then
Exit Sub
End If
You can enumerate through your lst2 to determine whether any of the values match your selected item, lst1.SelectedItem.
So loop,
Dim found As Boolean = False
For Each itm As String in lst2.Items
If itm = lst1.SelectedItem Then
found = True
End If
Next
If Not found Then
'Add it.
End If
Or you can simply use the Contains method:
If Not lst2.Items.Contains(lst1.SelectedItem) Then
'Add it.
End if.
Related
I have a DataGridView that is styled with code and is using data from a SQLite Database
The Database is NOT bound to the DataGridView. A number of events are triggered when I click on a row.
First the Database is updated with today's date.
And the cell that contain's that date reflects the change.
I then call a sort on the column based on the cells value. With this code
dgvLinks.Sort(dgvLinks.Columns(3), ListSortDirection.Ascending)
The process works as expected with no issues IF I omit these lines of code from the Sub Routine ViewSearches() that populates the DataGridView.
If rowCount <= 25 Then
maxRowCount = 25 - rowCount
For iA = 1 To maxRowCount
dgvLinks.Rows.Add(" ")
Next
End If
I can use these empty rows if I make a call to repopulate the DataGridView with ViewSearches()
I am trying to avoid this design as it seems like a over use of resource.
The ERROR that is happening is the 4 rows that contain data are moved to the bottom of the DataGridView and above these 4 rows with data are the empty rows. I will post the relevant code below.
My question How can I keep the empty rows and populate DataGridView so the rows with data are at the top of the DataGridView?
Here is a Screen Shot after I selected LID 2. It is updated and bubbled to the bottom of the DGV.
Private Sub ViewSearches()
Dim intID As Integer
Dim strChannelName As String
Dim strLinkAddress As String
Dim strLastVisit As String
Dim strLinkType As String
Dim rowCount As Integer
Dim maxRowCount As Integer
'Dim emptyStr As String = " "
Using conn As New SQLiteConnection($"Data Source = '{gv_dbName}';Version=3;")
conn.Open()
Using cmd As New SQLiteCommand("", conn)
'cmd.CommandText = "SELECT * FROM LinkTable"
' Line of CODE Above works with If statement in While rdr
'==========================================================
'cmd.CommandText = "SELECT * FROM LinkTable WHERE ytSiteType = 'News'"
cmd.CommandText = "SELECT * FROM LinkTable WHERE ytSiteType = #site"
cmd.Parameters.Add("#site", DbType.String).Value = gvSLT
Using rdr As SQLite.SQLiteDataReader = cmd.ExecuteReader
'dgvLinks.DataSource = rdr
'Statement Above use when DB is bound to dgvLinks
'=================================================
While rdr.Read()
intID = CInt((rdr("LID")))
strChannelName = rdr("ytChannelName").ToString
strLinkAddress = rdr("ytLinkAddress").ToString
strLastVisit = rdr("ytLastVisit").ToString
strLinkType = rdr("ytSiteType").ToString
'If strLinkType = gvSLT Then
dgvLinks.Rows.Add(intID, strChannelName, strLinkAddress, strLastVisit)
rowCount = rowCount + 1
'End If
End While
dgvLinks.Sort(dgvLinks.Columns(3), ListSortDirection.Ascending)
End Using
If rowCount <= 25 Then
maxRowCount = 25 - rowCount
For iA = 1 To maxRowCount
dgvLinks.Rows.Add(" ")
Next
End If
End Using
End Using
'FindEmpty()
End Sub
Click Event with Update to Database
Private Sub dgvLinks_CellClick(sender As System.Object, e As System.Windows.Forms.DataGridViewCellEventArgs) Handles dgvLinks.CellClick
selRow = e.RowIndex
If e.RowIndex = -1 Then
gvalertType = "4"
frmAlert.ShowDialog()
Exit Sub
End If
'Dim col As DataGridViewColumn = Me.dgvLinks.Columns(e.ColumnIndex)
Dim row As DataGridViewRow = Me.dgvLinks.Rows(e.RowIndex)
If row.Cells(2).Value Is Nothing Then
gvalertType = "5"
frmAlert.ShowDialog()
Return
Exit Sub
ElseIf gvTxType = "View" Then
webPAGE = row.Cells(2).Value.ToString()
siteID = CInt(row.Cells(0).Value.ToString())
UpdateSiteData()
''MsgBox("Stop " & selRow)
'dgvLinks.ClearSelection()
'dgvLinks.Refresh()
'dgvLinks.RefreshEdit()
Process.Start(webPAGE)
'dgvLinks.Columns.Clear()
''dgvLinks.Rows.Clear()
''ViewSearches()
ElseIf gvTxType = "Delete" Or gvTxType = "Update" Then
gvID = CInt(row.Cells(0).Value)
gvSiteName = row.Cells(1).Value.ToString
gvSiteURL = row.Cells(2).Value.ToString
frmADE.Show()
Close()
End If
End Sub
Update Routine
Public Sub UpdateSiteData()
Dim dateToday = Date.Today
dateToday = CDate(CDate(Date.Today).ToString("M-d-yyyy"))
Using conn As New SQLiteConnection($"Data Source = '{gv_dbName}';Version=3;"),
cmd As New SQLiteCommand("UPDATE LinkTable SET ytLastVisit = #ytLastVisit WHERE LID =" & siteID, conn)
conn.Open()
cmd.Parameters.Add("#ytLastVisit", DbType.String).Value = dateToday.ToString("M-d-yyyy")
cmd.ExecuteNonQuery()
dgvLinks.Rows(selRow).Cells(3).Value = dateToday.ToString("M-d-yyyy")
'Line of code above INSERTS value in Last Visit Column at the correct ROW
'NOT needed if you reload data from the database
'=========================================================================
'dgvLinks.Refresh()
'dgvLinks.RefreshEdit()
dgvLinks.Sort(dgvLinks.Columns(3), ListSortDirection.Ascending)
End Using
End Sub
You will see a number of things I have tried commented out.
As I said I can FIX the issue if I make a call to the ViewSearches() Sub Routine.
Private Sub StyleDGV()
'Sets Design of the DataGridView
'===============================
dgvLinks.DefaultCellStyle.Font = New Font("Times New Roman", 13.0F, FontStyle.Bold)
dgvLinks.ColumnCount = 4
dgvLinks.Columns(0).Width = 60 'ID
dgvLinks.Columns(1).Width = 325 'Site Name 325
dgvLinks.Columns(2).Width = 860 'Site Url 860
dgvLinks.Columns(3).Width = 154 'LastVisit 140
'Option with no blank rows increase col count to 5
'OR increase width of col(3) WHY? because the scroll bar is not showing
' TOTAL Width 1450 Height 488
'=============================
'To Set Col Header Size Mode = Enabled
'To Set Col Header Default Cell Styles DO in Properties
'dgvLinks.Columns(6).DefaultCellStyle.Format = "c"
dgvLinks.ColumnHeadersHeight = 10 'Sans Serif 'Tahoma
dgvLinks.ColumnHeadersDefaultCellStyle.Font = New Font("Sans Serif", 12.0F, FontStyle.Bold)
dgvLinks.ColumnHeadersDefaultCellStyle.ForeColor = Color.Blue
dgvLinks.DefaultCellStyle.BackColor = Color.LightGoldenrodYellow
'DGV Header Names
dgvLinks.Columns(0).Name = "LID"
dgvLinks.Columns(1).Name = "Site Name"
dgvLinks.Columns(2).Name = "Site URL"
dgvLinks.Columns(3).Name = "Last Visit"
dgvLinks.Columns(0).SortMode = DataGridViewColumnSortMode.NotSortable
dgvLinks.Columns(1).SortMode = DataGridViewColumnSortMode.NotSortable
dgvLinks.Columns(2).SortMode = DataGridViewColumnSortMode.NotSortable
dgvLinks.Columns(3).SortMode = DataGridViewColumnSortMode.NotSortable
End Sub
Any one following this question the FIX that permitted keeping the empty rows was to just omit the sort command in the Update to Database Sub Routine
As far as getting the data from the SQLite DB into the grid… you almost have it in the ViewSearches method. The command text looks good; however you are using an SQLiteDataReader. This is resorting to reading the data line by line.
I suggest you use the SQLiteDataAdapter instead. With it you can get the DataTable from the DB in one shot. First create and initialize a DataSet, then create a new SQLiteDataAdapter then add your command to the data adapter something like…
DataSet ds = new DataSet();
using (SQLiteDataAdapter sqlDA = new SQLiteDataAdapter()) {
conn.Open();
sqlDA.SelectCommand = cmd.CommanText;
sqlDA.Fill(ds, “tableName”);
if (ds.Tables.Count > 0) {
//return ds.Tables[“tableName”];
dgvLinks.DataSource = ds.Tables[“tableName”];
}
}
This will add a DataTable to the DataSet ds called “tableName” if the query succeeded.
Then simply use that DataTable as a DataSource to the grid… something like…
dgvLinks.DataSource = ds.Tables[“tableName”];
i am trying to create tree view and some error i can not fix it
Sub CREATENODE()
Dim TRN As New TreeNode
Dim DT As New DataTable
DT.Clear()
DT = ACCOUNTTableAdapter.TREE_ACCOUNT()
For I As Integer = 0 To DT.Rows.Count - 1
If DT.Rows(I)(9).ToString() = "00000000-0000-0000-0000-000000000000" Then
TRN = New TreeNode(DT.Rows(I)(3).ToString() + " " + DT.Rows(I)(4).ToString())
TRN.Tag = DT.Rows(I)(1).ToString()
If DT.Rows(I)(7).ToString() <> "0" Then
TRN.ImageIndex = 0
TRN.SelectedImageIndex = 0
Else
TRN.ImageIndex = 1
TRN.SelectedImageIndex = 1
End If
TreeView1.Nodes.Add(TRN)
End If
Next
''For Each NODE As TreeNode In TreeView1.Nodes
'' CHELD(NODE)
'Next
End Sub
This is nonsense
Dim TRN As New TreeNode
Dim DT As New DataTable
DT.Clear()
DT = ACCOUNTTableAdapter.TREE_ACCOUNT()
You create a New TreeNode and then inside the loop you overwrite it with another New one. Just put the Dim inside the loop after the if.
Dim TRN = New TreeNode($"{row(3)} {row(4)}")
You create a brand new DataTable. Then you clear it when it can't possibly have anything in it. Then you throw it away and assign a different DataTable to it.
Just do
Dim DT = ACCOUNTTableAdapter.TREE_ACCOUNT()
I have simplified your code by using a For Each loop. Also, I used and interpolated string indicated by the $ preceding the string. Variables can be inserted in place surrounded by braces { }.
As far as the actual problem, you need to create an instance of your table adapter with the New keyword. Then call the appropriate method. A simple application will just use .GetData.
Private Sub CREATENODE()
Dim DT = (New ACCOUNTTableAdapter).TREE_ACCOUNT() 'See what intellisense offers. It may be just .GetData
For Each row As DataRow In DT.Rows
If row(9).ToString() = "00000000-0000-0000-0000-000000000000" Then
Dim TRN = New TreeNode($"{row(3)} {row(4)}")
TRN.Tag = row(1)
If row(7).ToString() <> "0" Then
TRN.ImageIndex = 0
TRN.SelectedImageIndex = 0
Else
TRN.ImageIndex = 1
TRN.SelectedImageIndex = 1
End If
TreeView1.Nodes.Add(TRN)
End If
Next
End Sub
Hint: Why not put the entire row in the Tag property. You will have access to all the fields by casting the Tag back to a DataRow.
I have the following requirement,
I have a ComboBox Control (DropDownList Style) which user has to select a given value, but can not edit. Then I save it to a Database Table, and it's working fine.
(dataRow("it_discount_profile") = Trim(cmbDisProfile.Text))
But when I try to show the same Data in the same ComboBox by retrieving it from the Database, it won't show.
(cmbDisProfile.Text = Trim(tempTb.Rows(0).Item("it_discount_profile")))
When I change the ComboBox to "DropDown Style", it works. But then the User can edit it.
Am I missing something here or is it like that? Any advice will be highly appreciated.
Im filling it in runtime using a procedure.
Private Sub filldisProfiles()
Dim sqlString As String = "SELECT discount_profile FROM tb_discount_profiles"
Dim tempTb As DataTable
Dim myTbClass As myClassTableActivities = New myClassTableActivities()
tempTb = myTbClass.myFunctionFetchTbData(sqlString)
cmbDisProfile.DataSource = tempTb
cmbDisProfile.DisplayMember = "discount_profile"
End Sub
Ok. Actually, Im trying to migrate one of my old project from VB to VB.Net. VB.Net is little new to me. Im using a self built classto reduce codes in other places. Im attaching the class below.
My actual requirement is to populate the combo box from a table. I like to do it in run time. I don't want users to edit it. If they want to add a new value, they have separate place (Form) for that. I think im doing it in a wrong way. If possible please give a sample code since I'm not familiar with the proposed method.
Public Function myFunctionFetchTbData(ByVal inputSqlString As String) As DataTable
Try
Dim SqlCmd As New SqlCommand(inputSqlString, conn)
Dim dataAdapter As New SqlDataAdapter(SqlCmd)
Dim fetchedDataSet As New DataSet
fetchedDataSet.Clear()
dataAdapter.Fill(fetchedDataSet)
Dim fetchedDataTable As DataTable = fetchedDataSet.Tables(0)
Return fetchedDataTable
Catch ex As Exception
MsgBox(Err.Description)
End Try
End Function
' this sub will update a table
Public Sub MyMethodUpdateTable(ByVal sqlString As String, ByVal tbToUpdate As DataTable)
Dim SqlCmd As New SqlCommand(sqlString, conn)
Dim dataAdapter As New SqlDataAdapter(SqlCmd)
Dim objCommandBuilder As New SqlClient.SqlCommandBuilder(dataAdapter)
dataAdapter.Update(tbToUpdate)
End Sub
Public Function MyMethodfindRecord(ByVal strSearckKey As String, ByVal tableName As String, ByVal strColumnName As String) As Boolean
Try
Dim searchSql As String = "SELECT * FROM " & tableName & " WHERE " & strColumnName & "='" & strSearckKey & "'"
'Dim searchString As String = txtCategoryCode.Text
' searchOwnerCmd.Parameters.Clear()
' searchOwnerCmd.Parameters.AddWithValue("a", "%" & search & "%")
Dim tempTb As DataTable
Dim myTbClass As myClassTableActivities = New myClassTableActivities()
tempTb = myTbClass.myFunctionFetchTbData(searchSql)
If tempTb.Rows.Count = 0 Then
Return False
Else
Return True
End If
Catch ex As Exception
MsgBox(Err.Description)
End Try
End Function
Public Function myFunctionFetchSearchTB(ByVal inputSqlString As String) As DataTable
Try
Dim SqlCmd As New SqlCommand(inputSqlString, conn)
Dim dataAdapter As New SqlDataAdapter(SqlCmd)
Dim fetchedDataSet As New DataSet
fetchedDataSet.Clear()
dataAdapter.Fill(fetchedDataSet)
Dim fetchedSearchTB As DataTable = fetchedDataSet.Tables(0)
Return fetchedSearchTB
Catch ex As Exception
MsgBox(Err.Description)
End Try
End Function
OK. If I understood correctly, you have a problem in retrieving Data [String] from a Database Table into a ComboBox of DropDownStyle [DropDownList].
How do you fill/populate your ComboBox with Data From Database Table ?
In this link, Microsoft docs state, that:
Use the SelectedIndex property to programmatically determine the index
of the item selected by the user from the DropDownList control. The
index can then be used to retrieve the selected item from the Items
collection of the control.
In much more plain English
You can never SET ComboBox.Text Value while in DropDownList by code, which you already knew by testing your code, but you need to use DisplayMember and ValueMember or SelectedIndex.
ComboBox1.SelectedIndex = ComboBox1.FindStringExact(Trim(tempTb.Rows(0).Item("it_discount_profile")))
Please consider populating your ComboBox Control from Database Table using (Key,Value) Dictionary collection, here is an example
Thank you guys for all the advice's. The only way it can be done is the way u said. I thought of putting the working code and some points for the benefit of all.
proposed,
ComboBox1.SelectedIndex = comboBox1.FindStringExact(Trim(tempTb.Rows(0).Item("it_discount_profile")))"
does not work when u bind the datatable to the combobox. The values should be added to the combo box in run time if the above "SelectedIndex" method to work. The code to add items to the combobox is as follows(myClassTableActivities is a class defined by myself and its shown above),
Private Sub filldisProfiles()
Dim sqlString As String = "SELECT discount_profile FROM tb_discount_profiles"
Dim tempTb As DataTable
Dim myTbClass As myClassTableActivities = New myClassTableActivities()
tempTb = myTbClass.myFunctionFetchTbData(sqlString)
Dim i As Integer = 0
For i = 0 To tempTb.Rows.Count - 1
cmbDisProfile.Items.Add(Trim(tempTb.Rows(i).Item("discount_profile")))
Next
End Sub
After adding we can use the following code to display the data on combobox (DropDownList).
Private Sub txtItCode_TextChanged(sender As Object, e As EventArgs) Handles txtItCode.TextChanged
Try
Dim sqlString As String = "SELECT * FROM tb_items where it_code='" & Trim(txtItCode.Text) & "'"
Dim tempTb As DataTable
Dim myTbClass As myClassTableActivities = New myClassTableActivities()
tempTb = myTbClass.myFunctionFetchTbData(sqlString)
If Len(txtItCode.Text) < 4 Then
cmdAdd.Enabled = False
cmdDelete.Enabled = False
cmdSave.Enabled = False
Else
If tempTb.Rows.Count > 0 Then
With tempTb
txtItName.Text = Trim(tempTb.Rows(0).Item("it_name"))
cmbDisProfile.SelectedIndex = cmbDisProfile.FindStringExact(Trim(tempTb.Rows(0).Item("it_discount_profile")))
cmbProfitProfile.SelectedIndex = cmbProfitProfile.FindStringExact(Trim(tempTb.Rows(0).Item("it_profit_profile")))
cmbItCategory.SelectedIndex = cmbItCategory.FindStringExact(Trim(tempTb.Rows(0).Item("it_category")))
cmbFinanCategory.SelectedIndex = cmbFinanCategory.FindStringExact((tempTb.Rows(0).Item("it_finance_category")))
End With
cmdAdd.Enabled = False
cmdDelete.Enabled = True
cmdSave.Enabled = True
Else
cmdAdd.Enabled = True
cmdDelete.Enabled = False
cmdSave.Enabled = False
txtItName.Text = ""
Call fillItCategories()
Call fillProProfile()
Call filldisProfiles()
Call fillFinCat()
End If
End If
Catch ex As Exception
MsgBox(ex.Message)
End Try
I have one combobox in my app that gets populated with a dozen or so items from SQL SERVER. I am currently trying to allow user to be able to type in a new value into the combobox and save it to a table in SQL SERVER. I'm looking for something along the lines of a DropDownStyle of DropDown and DropDownList. Basically I'm hoping to let the user type in the combobox, however if the value is not there, i want to be able to give them an option of saving it (probably on lost focus). I'm wondering what would be a good way of doing something like that.
On lost focus should I basically go through each item that is currently in the drop down and check it against the value entered?
EDIT:
Sql="SELECT IDvalue, TextName from TblReference"
Dim objconn As New SqlConnection
objconn = New SqlConnection(conn)
objconn.Open()
Dim da As New SqlDataAdapter(sql, objconn)
Dim ds As New DataSet
da.Fill(ds, "Name")
If ds.Tables("Name").Rows.Count > 0 Then
Dim dr As DataRow = ds.Tables("Name ").NewRow
ds.Tables("Name").Rows.InsertAt(dr, 0)
With c
.DataSource = ds.Tables("Name")
.ValueMember = " IDvalue "
.DisplayMember = " TextName "
End With
End If
You are already adding a fake/blank row to a table, you can do the same thing for a new item.
' form level datatable var
Private cboeDT As DataTable
Initializing:
cboeDT = New DataTable
Dim sql = "SELECT Id, Descr FROM TABLENAME ORDER BY Descr"
Using dbcon As New MySqlConnection(MySQLConnStr)
Using cmd As New MySqlCommand(sql, dbcon)
dbcon.Open()
cboeDT.Load(cmd.ExecuteReader())
' probably always need this even
' when there are no table rows (???)
Dim dr = cboeDT.NewRow
dr("Id") = -1 ' need a way to identify it
dr("Descr") = ""
cboeDT.Rows.InsertAt(dr, 0)
End Using
End Using
cboeDT.DefaultView.Sort = "Descr ASC"
cboE.DataSource = cboeDT
cboE.DisplayMember = "Descr"
cboE.ValueMember = "Id"
Note Users tend to have a preference as to the order of these things. The simple creatures tend to prefer alphabetical over a DB Id they may never see. To accommodate them, the DefaultView is sorted so that any new rows added will display in the correct order.
Add new items in the Leave event (much like Steve's):
Private Sub cboE_Leave(sender ...
' if it is new, there will be no value
If cboE.SelectedValue Is Nothing Then
' alternatively, search for the text:
'Dim item = cboeDT.AsEnumerable().
' FirstOrDefault(Function(q) String.Compare(q.Field(Of String)("Descr"),
' cboE.Text, True) = 0)
'If item Is Nothing Then
' ' its new...
Dim newid = AddNewItem(cboE.Text)
Dim dr = cboeDT.NewRow
dr("Id") = newid
dr("Descr") = cboE.Text
cboeDT.Rows.Add(dr)
' fiddling with the DS looses the selection,
' put it back
cboE.SelectedValue = newid
End If
End Sub
If you want to search by text:
Dim item = cboeDT.AsEnumerable().
FirstOrDefault(Function(q) String.Compare(q.Field(Of String)("Descr"),
cboE.Text, True) = 0)
If item Is Nothing Then
' its new...
...
Inserting will vary a little depending on the actual db. A key step though is to capture and return the ID of the new item since it is needed for the CBO:
Private Function AddNewItem(newItem As String) As Int32
Dim sql = "INSERT INTO MY_TABLE (Descr) VALUES (#v); SELECT LAST_INSERT_ID();"
Dim newId = -1
Using dbcon As New MySqlConnection(MySQLConnStr)
Using cmd As New MySqlCommand(sql, dbcon)
dbcon.Open()
cmd.Parameters.Add("#v", MySqlDbType.String).Value = newItem
' MySql provides it in the command object
If cmd.ExecuteNonQuery() = 1 Then
newId = Convert.ToInt32(cmd.LastInsertedId)
End If
End Using
End Using
Return newId
End Function
As noted MySql provides the LastInsertedID as a command object property. In SQL SERVER, tack ...";SELECT LAST_INSERT_ID();" to the end of your SQL and then:
newId = Convert.ToInt32(cmd.ExecuteScalar())
This is not conceptually very different from Steve's answer, except it uses the DataTable you build rather than collections which makes it (very) slightly simpler.
The way I do this, is on window load I perform a new SQL query to get the list of values in the table, and load them into a combobox.
Then once focus is lost, it then checks what's currently typed into the combobox against the current values already loaded. If it doesn't exist, then it's not in SQL. Something like the following...
Dim found As Boolean = False
For i As Integer = 0 To comboBox.Items.Count - 1
Dim value As String = comboBox.Items(i).ToString()
If comboBox.Text = value Then
found = True
End If
Next
If found = False Then
'the item doesn't exist.. add it to SQL
Else
'the item exists.. no need to touch SQL
End If
First thing I would do is to build a simple class to hold your values through a List of this class
Public Class DataItem
Public Property IDValue As Integer
Public Property TextName as String
End Class
Now, instead of building an SqlDataAdapter and fill a dataset, work with an SqlDataReader and build a List(Of DataItem)
' Class global...
Dim allItems = new List(Of DataItem)()
Sql="SELECT IDvalue, TextName from TblReference"
' Using to avoid leaks on disposable objects
Using objconn As New SqlConnection(conn)
Using cmd As New SqlCommand(Sql, objconn)
objconn.Open()
Using reader = cmd.ExecuteReader()
While reader.Read()
Dim item = new DataItem() With { .IDValue = reader.GetInt32(0), .TextName = reader.GetString(1)}
allItems.Add(item)
End While
End Using
if allItems.Count > 0 Then
allItems.Insert(0, new DataItem() With {.IDValue = -1, .TextValue = ""}
Dim bs = new BindingList(Of DataItem)(allItems)
c.DataSource = bs
c.ValueMember = "IDvalue"
c.DisplayMember = "TextName"
End If
End Using
End Using
Now the code that you want to add to your Leave event for the combobox
Sub c_Leave(sender As Object, e As EventArgs) Handles c.Leave
If Not String.IsNullOrEmpty(c.Text) Then
Dim bs = DirectCast(c.DataSource, BindingList(Of DataItem))
if bs.FirstOrDefault(Function(x) x.TextName = c.Text) Is Nothing Then
Dim item = new DataItem() With { .IDValue = -1, .TextName = c.Text}
bs.Add(item)
' here add the code to insert in the database
End If
End If
End Sub
How do i loop through each data in the datalist? Because i am currently getting one value from "Label8" which causes my "Label7" to show "No" for all.
Protected Sub DataList2_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataListItemEventArgs) Handles DataList2.ItemDataBound
For Each li As DataListItem In DataList2.Items
Dim labelasd As Label = DirectCast(e.Item.FindControl("**Label8**"), Label)
Dim reviewid As Integer = labelasd.Text
Dim connectionString As String = _
ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString
Dim connection As SqlConnection = New SqlConnection(connectionString)
connection.Open()
Dim sql As String = "Select Count(reviewYes) AS Expr1 From ProductReviewHelp Where ProductReviewID = " & reviewid & ""
Dim command As SqlCommand = New SqlCommand(sql, connection)
Dim reader As SqlDataReader = command.ExecuteReader()
Dim countofreview As Integer = 0
Dim reviewcountboolean As Boolean
If (reader.Read()) Then
If (IsDBNull(reader.GetValue(0)) = False) Then
countofreview = reader.GetValue(0)
End If
End If
If countofreview = 0 Then
reviewcountboolean = False
Else
reviewcountboolean = True
End If
If (reviewcountboolean = True) Then
Dim label1 As Label = DirectCast(e.Item.FindControl(**"Label7"**), Label)
label1.Text = "Hello"
ElseIf (reviewcountboolean = False) Then
Dim label1 As Label = DirectCast(e.Item.FindControl(**"Label7"**), Label)
label1.Text = "No"
End If
Next
End Sub
How do i loop through each data in the datalist? Because i am currently getting one value from "Label8" which causes my "Label7" to show "No" for all.
You are looping on your DataList2 items but, at every loop, you update the label7 with the logic of the current item, effectively removing the result of the previous loop. This means that, when you reach the last item, the Label7 will reflect the string "Hello" or "No" depending on the logic applied to the last item in your loop.
Apart from this logical error, you have also numerous errors in the code shown.
The connection is never closed.
You use string concatenation instead of parameters.
You use ExecuteReader when in this case an ExecuteScalar is better
suited.
You can iterate through then using a loop here is an example
Try
readFromDL1 = DirectCast(SqlDataSource1.Select(DataSourceSelectArguments.Empty), DataView)
readFromQ = DirectCast(SqlDataSource7.Select(DataSourceSelectArguments.Empty), DataView)
Catch ex As Exception
End Try
'End
'datalist1
i = 0
_rowCount = DataList1.Items.Count
If _rowCount > 0 Then
_getCall = DataList1.Items.Item(i).FindControl("lnkEdit")
End If
For Each readr As DataRowView In readFromQ
findQNumber = readr(1).ToString()
For Each readfdlr1 As DataRowView In readFromDL1
findQNumber1 = readfdlr1(1).ToString
Try
indexofitems = DataList1.Items.Item(i1).ItemIndex
If findQNumber.ToString = findQNumber1.ToString Then
_getCall = DataList1.Items.Item(indexofitems).FindControl("lnkEdit")
_getCall.Text = "Called"
_getCall.Enabled = False
_getCall.ForeColor = Drawing.Color.Red
_getCall.BackColor = Drawing.Color.Yellow
End If
i1 = i1 + 1
Catch e As Exception
End Try
Next
i1 = 0
i = i + 1