Data table is not functioning properly, it even causes my dynamic table layout not showing. And I have absolutely no idea what went wrong. By the way, i'm a beginner.
Public Class ListItem
Dim dt As System.Data.DataTable
Private Sub ListItem_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Dim conn As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source =|DataDirectory|\SMS.accdb"
Dim sqlstr As String = "Select * from ItemList"
Dim dtad As New OleDb.OleDbDataAdapter(sqlstr, conn)
dtad.Fill(dt)
dtad.Dispose()
End Sub
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim ListTable As New TableLayoutPanel()
ListTable.AutoSize = True
ListTable.AutoSizeMode = Windows.Forms.AutoSizeMode.GrowAndShrink
ListTable.Location = New Point(20, 20)
ListTable.BackColor = Color.White
ListTable.ColumnCount = CInt(dt.Columns.Count)
ListTable.RowCount = CInt(dt.Rows.Count)
ListTable.CellBorderStyle = TableLayoutPanelCellBorderStyle.Single
For colindex = 0 To dt.Columns.Count - 1
For rowindex = 0 To 0
Dim newlabel As New Label()
newlabel.Location = New Point(10, 10)
newlabel.Name = "label" & colindex
newlabel.Font = New Drawing.Font("Microsoft Sans Serif", 16, FontStyle.Underline)
newlabel.Text = dt.Columns(colindex).ColumnName
newlabel.AutoSize = True
ListTable.Controls.Add(newlabel, colindex, rowindex)
Next
Next
Controls.Add(ListTable)
End Sub
End Class
It gives me this error:
An unhandled exception of type 'System.NullReferenceException' occurred in StockManagementSystem.exe
Additional information: Object reference not set to an instance of an object.
Very first line inside the class. Change it from this:
Dim dt As System.Data.DataTable
to this:
Dim dt As New System.Data.DataTable
Related
I am displaying data from the database into vb.net calendar, but I keep on getting the error
"SelectedDate = error BC30451: 'SelectedData' is not declared. It may be inaccessible due to its protection level."
I am not sure what cause the error to happen. Below is my code:
Protected Function GetData() As Data.DataTable
If conn.State = ConnectionState.Closed Then
conn.ConnectionString = constr.ToString()
conn.Open()
End If
strquery = "SELECT * FROM Event"
_SqlDataAdapter = New SqlDataAdapter(strquery, conn)
datatable = New DataTable
_SqlDataAdapter.Fill(datatable)
Return datatable
End Function
Protected Calendar1_DayRender(ByVal sender As Object, ByVal e Ad DayRenderEventArsgs)
Dim dt As Data.DataTable = datatable
Dim lblEvent = New Label()
e.Day.IsSelectable = False
For Each row As Data.DataRow In dt.Rows
If Convert.ToDateTime(e.Day.Date) = Convert.ToDateTime(row("eventDate")) Then
e.Cell.Controls.Add(New Label With {.Text = "<br/>"})
lblEvent.Text = row("event_desc")
e.Cell.Controls.Add(lblEvent)
lblEvent.Attributes.Add("style", "background-color: #01a9ac;border: #01a9ac;color: #fff;padding: 3px;padding-left: 50px;padding-right: 50px;")
End If
Next
End Sub
Protect Sub Calendar1_SelectinChanged(ByVal sender As Object, ByVal e As System.EventArgs)
Dim strdatenow As String
Dim dateTimenow = DateTime.Now()
Dim nowDate = dateTimenow.Date
Calendar1.SelectedDate = nowDate
strdatenow = Calendar1.SelectedDate.ToString()
End Sub
Appreciate if anyone can help me on this issue.
The following code isn't working when exporting the datagridview data when trying to make it vertical with headers along the left side along with text beside each one. Once this is flipped the user would click on button1 to export to excel.
Imports System.Data.DataTable
Imports System.IO
Imports Microsoft.Office.Interop
Public Class Form1
Dim table As New DataTable(0)
Public checkBoxList As List(Of CheckBox)
Private ds As DataSet = Nothing
Private dt As DataTable = Nothing
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
ds = New DataSet()
dt = New DataTable()
ds.Tables.Add("Table")
Dim my_DataView As DataView = ds.Tables(0).DefaultView
DataGridView1.DataSource = my_DataView
table.Columns.Add("Forename", Type.GetType("System.String"))
table.Columns.Add("Surname", Type.GetType("System.String"))
table.Columns.Add("Food", Type.GetType("System.String"))
checkBoxList = New List(Of CheckBox) From {CheckBox1, CheckBox2, CheckBox3, CheckBox4}
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim currentDataSet As DataSet = FlipDataSet(ds) ' Flip the DataSet
Dim values As String = "" &
String.Join(" & ", checkBoxList _
.Where(Function(cb) cb.Checked).Select(Function(cb) cb.Text))
' use values for placing into your DataGridView
CheckBox1.Text = values
CheckBox2.Text = values
CheckBox3.Text = values
CheckBox4.Text = values
table.Rows.Add(TextBox1.Text, TextBox2.Text, values.ToString)
DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill
DataGridView1.RowTemplate.Height = 100
DataGridView1.AllowUserToAddRows = False
DataGridView1.DataSource = table
'Save to excel with headers
Dim ExcelApp As Object, ExcelBook As Object
Dim ExcelSheet As Object
Dim i As Integer
Dim j As Integer
'create object of excel
ExcelApp = CreateObject("Excel.Application")
ExcelBook = ExcelApp.WorkBooks.Add
ExcelSheet = ExcelBook.WorkSheets(1)
With ExcelSheet
For Each column As DataGridViewColumn In DataGridView1.Columns
.cells(1, column.Index + 1) = column.HeaderText
Next
For i = 1 To Me.DataGridView1.RowCount
.cells(i + 1, 1) = Me.DataGridView1.Rows(i - 1).Cells("Forename").Value
For j = 1 To DataGridView1.Columns.Count - 1
.cells(i + 1, j + 1) = DataGridView1.Rows(i - 1).Cells(j).Value
Next
Next
End With
ExcelApp.Visible = True
'
ExcelSheet = Nothing
ExcelBook = Nothing
ExcelApp = Nothing
End Sub
Private Sub DataGridView1_CellContentClick(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
End Sub
Public Function FlipDataSet(ByVal my_DataSet As DataSet) As DataSet
Dim ds As New DataSet()
For Each dt As DataTable In my_DataSet.Tables
Dim table As New DataTable()
For i As Integer = 0 To dt.Rows.Count
table.Columns.Add(Convert.ToString(i))
Next
Dim r As DataRow
For k As Integer = 0 To dt.Columns.Count - 1
r = table.NewRow()
r(0) = dt.Columns(k).ToString()
For j As Integer = 1 To dt.Rows.Count
r(j) = dt.Rows(j - 1)(k)
Next
table.Rows.Add(r)
Next
ds.Tables.Add(table)
Next
Return ds
End Function
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim currentDataSet As DataSet = FlipDataSet(ds) ' Flip the DataSet
Dim currentDataView As DataView = currentDataSet.Tables(0).DefaultView
DataGridView1.DataSource = currentDataView
Button2.Enabled = False
End Sub
End Class
When clicking button2 it should flip the data with the following;
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles
Button2.Click
Dim currentDataSet As DataSet = FlipDataSet(ds) ' Flip the DataSet
Dim currentDataView As DataView = currentDataSet.Tables(0).DefaultView
DataGridView1.DataSource = currentDataView
Button2.Enabled = False
End Sub
End Class
I've tried debugging but it i can't seem to find anything wrong? It will allow me to insert data in the textbox's whilst selecting checkbox's and when clicking button 1 to export it works fine, but it doesn't flip the data.
Please can anyone suggest how to fix this as i have a presentation on the 8th June and this data needs to automatically be flipped
Sourcecode: Download Myproject
Image of target
Answered:
Imports Microsoft.Office.Interop
Imports System.Runtime.InteropServices
Public Class Form1
Private ds As DataSet = Nothing
Private dt As DataTable = Nothing
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
DataGridView1.AllowUserToAddRows = False
dt = New DataTable("MyTable")
dt.Columns.Add("Forename", Type.GetType("System.String"))
dt.Columns.Add("Surname", Type.GetType("System.String"))
dt.Columns.Add("Food", Type.GetType("System.String"))
ds = New DataSet
ds.Tables.Add(dt)
Dim my_DataView As DataView = ds.Tables("MyTable").DefaultView
DataGridView1.DataSource = my_DataView
End Sub
Private Sub Button_AddRowData_Click(sender As Object, e As EventArgs) Handles Button_AddRowData.Click
Dim foods As String = String.Join(" & ", CheckedListBox1.CheckedItems.Cast(Of String))
dt.Rows.Add(New Object() {TextBox_Forename.Text, TextBox_Surname.Text, foods})
End Sub
Private Sub Button_FlipAndSave_Click(sender As Object, e As EventArgs) Handles Button_FlipAndSave.Click
FlipAndSave(ds.Tables("MyTable"))
End Sub
Private Sub FlipAndSave(table As DataTable)
Dim ExcelApp As New Excel.Application
Dim WrkBk As Excel.Workbook = ExcelApp.Workbooks.Add()
Dim WrkSht As Excel.Worksheet = CType(WrkBk.Worksheets(1), Excel.Worksheet)
With WrkSht
For ci As Integer = 0 To table.Columns.Count - 1
.Cells(ci + 1, 1) = table.Columns(ci).ColumnName
Next
For ri As Integer = 0 To table.Rows.Count - 1
For ci As Integer = 0 To table.Columns.Count - 1
.Cells(ci + 1, ri + 2) = table.Rows(ri).Item(ci).ToString
Next
Next
End With
ExcelApp.Visible = True
'use this lines if you want to automatically save the WorkBook
'WrkBk.SaveAs("C:\Some Folder\My Workbook.xlsx") '(.xls) if you have an old version of Excel
'ExcelApp.Quit() 'use this line if you want to close the Excel Application
ReleaseObject(ExcelApp)
ReleaseObject(WrkBk)
ReleaseObject(WrkSht)
End Sub
Private Sub ReleaseObject(obj As Object)
Marshal.ReleaseComObject(obj)
obj = Nothing
End Sub
End Class
I am getting Object reference not set to an instance of an object error on chart creation with threads, It was running fine without threads but I have to do it with threads, please help
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
trd = New Thread(AddressOf ThreadTask)
trd.IsBackground = True
trd.Start()
End sub
Function
Private Sub ThreadTask()
Dim Data As String() = Functions.runAnalyticsReportSample(100278)
Functions.CredHolder(Session("User"), Session("Pw"))
Dim split As String() = {""}
Dim table As New DataTable()
Dim colB As DataColumn = table.Columns.Add("A", GetType(String))
Dim colD As DataColumn = table.Columns.Add("B", GetType(String))
For Each line In Data
split = line.Split(","c)
Dim row As DataRow = table.NewRow()
row.SetField(colB, split(0))
row.SetField(colD, split(1))
table.Rows.Add(row)
Next
'Chart1.Series.Add("test")
Chart1.Series("Series1").XValueMember = "A"
Chart1.Series("Series1").YValueMembers = "B"
Chart1.Series("Series1").IsValueShownAsLabel = True
Chart1.Series("Series1").IsVisibleInLegend = False
Chart1.DataSource = table
Chart1.DataBind()
End Sub
I am currently working in windows form applications using vb.net 2013. I have two forms, we can call them form1 and form 2 for now. Form1 has a datagridview with a checkbox column that the end user will click to open form2 as a dialog form. Once form2 opens I want it to automatically load and fill two text boxes that have information from corresponding columns from the original DGV. In short, the DGV on form1 has 3 columns; JobNumber, LineNumber, and the checkbox. The end user will click the checkbox to bring up form2 and I want the Jobnumber and Linenumber to automaticaly fill into two textboxes on form2. Here is my code from form1.
'assembly dialog result form
dr = f.ShowDialog
If dr = Windows.Forms.DialogResult.OK Then
'dim y as job string
Dim Y As String = DataGridOrdered.Rows(e.RowIndex).Cells(3).Value
'open connection
Using conn1 As New SqlConnection(connstring)
conn1.Open()
Using comm1 As SqlCommand = New SqlCommand("UPDATE Production.dbo.tblFCOrdered SET Complete = 1, RackIn = 1 WHERE JobNumber = '" & Y & "'", conn1)
comm1.ExecuteNonQuery()
conn1.Close()
End Using
End Using
Call DGVOrderedRefresh()
ElseIf dr = Windows.Forms.DialogResult.Yes Then
'dim M as job string
Dim M As String = DataGridOrdered.Rows(e.RowIndex).Cells(3).Value
'open connection
Using conn1 As New SqlConnection(connstring)
conn1.Open()
Using comm1 As SqlCommand = New SqlCommand("UPDATE Production.dbo.tblFCOrdered SET Complete = 1, RackIn = 1 WHERE JobNumber = '" & M & "'", conn1)
comm1.ExecuteNonQuery()
conn1.Close()
End Using
End Using
Call DGVOrderedRefresh()
ElseIf dr = Windows.Forms.DialogResult.Cancel Then
'refresh datagridview ordered
Call DGVOrderedRefresh()
End If
ElseIf e.ColumnIndex = 0 Then
'fail safe to make sure the header is not clicked
If e.RowIndex = -1 Then
Exit Sub
End If
The code for my dialog is as follows
Imports System.Data
Imports System.Data.SqlClient
Public Class BuildName
' Dim connstring As String = "DATA SOURCE = BNSigma\CORE; integrated security = true"
Dim connstring As String = "DATA SOURCE = BNSigma\TEST; integrated security = true"
Private Sub Label3_Click(sender As Object, e As EventArgs) Handles Label3.Click
End Sub
Private Sub BuildName_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim ds As New DataTable
Try
'load name combo box
Using conn1 As New SqlConnection(connstring)
conn1.Open()
Using comm1 As SqlCommand = New SqlCommand("SELECT Name FROM Production.dbo.FCNames", conn1)
Dim adapater As New SqlDataAdapter
adapater.SelectCommand = comm1
adapater.Fill(ds)
adapater.Dispose()
conn1.Close()
CBName.DataSource = ds
CBName.DisplayMember = "Name"
CBName.ValueMember = "Name"
End Using
End Using
Catch ex As Exception
MsgBox("Error loading name List, please contact a mfg. Engr.!")
MsgBox(ex.ToString)
End Try
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
'Update built by name
Dim v As Object = TBFloor.Text
Dim G As Object = TBLine.Text
Dim O As Object = TBJobNumber.Text
Try
Using conn1 As New SqlConnection(connstring)
conn1.Open()
Using comm1 As SqlCommand = New SqlCommand("UPDATE Production.dbo.tblFCOrdered SET BuiltBy = #Name Where JobNumber = '" & O & "'", conn1)
comm1.Parameters.AddWithValue("#Name", CBName.Text)
comm1.ExecuteNonQuery()
conn1.Close()
End Using
End Using
Catch ex As Exception
MsgBox("Error updating Ordered table, please contact a MFG. ENGR.!")
MsgBox(ex.ToString)
End Try
End Sub
End Class
UPDATED CODE FOR VALTER
Form1 code
Public row_Index As Integer = 0
Private Sub DataGridOrdered_CurrentCellDirtyStateChanged(sender As Object, e As EventArgs) Handles DataGridOrdered.CurrentCellDirtyStateChanged
If DataGridOrdered.IsCurrentCellDirty Then
DataGridOrdered.CommitEdit(DataGridViewDataErrorContexts.Commit)
End If
End Sub
Private Sub DataGridOrdered_CellValueChanged(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridOrdered.CellValueChanged
If DataGridOrdered.Columns(e.ColumnIndex).Name = 9 Then
Dim checkCell As DataGridViewCheckBoxCell = CType(DataGridOrdered.Rows(e.RowIndex).Cells(9), DataGridViewCheckBoxCell)
If CType(checkCell.Value, [Boolean]) = True Then
row_Index = e.RowIndex
BuildName.ShowDialog(Me)
End If
End If
End Sub
Form 2 code
Private Sub BuildName_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim value1 As Object = FormOrdered.DataGridOrdered.Rows(FormOrdered.row_Index).Cells(3).Value
Dim value2 As Object = FormOrdered.DataGridOrdered.Rows(FormOrdered.row_Index).Cells(4).Value
TBJobNumber.Text = CType(value1, String)
TBFloor.Text = CType(value2, String)
In your form1 add:
Public Row_Index As Integer = 0 //use a simple variable
Sub datagridOrdered_CurrentCellDirtyStateChanged( _
ByVal sender As Object, ByVal e As EventArgs) _
Handles datagridOrdered.CurrentCellDirtyStateChanged
If datagridOrdered.IsCurrentCellDirty Then
datagridOrdered.CommitEdit(DataGridViewDataErrorContexts.Commit)
End If
End Sub
Private Sub datagridOrdered_CellValueChanged(sender As System.Object, e As System.Windows.Forms.DataGridViewCellEventArgs) Handles datagridOrdered.CellValueChanged
If datagridOrdered.Columns(e.ColumnIndex).Name = "Assemble" Then //<- here
Dim checkCell As DataGridViewCheckBoxCell = _
CType(datagridOrdered.Rows(e.RowIndex).Cells(2), _ //<- here
DataGridViewCheckBoxCell)
If CType(checkCell.Value, [Boolean]) = True Then
//RowIndex = e.RowIndex you dont need this
Row_Index = e.RowIndex
BuildName.ShowDialog(Me)
End If
End If
End Sub
//Nor this
//Private _count As Integer
//Public Property RowIndex() As Integer
//Get
//Return _count
//End Get
//Set(value As Integer)
//_count = value
//End Set
//End Property
And in dialog load event use Form1.Row_Index instead:
Private Sub BuildName_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim value1 As Object = FormOrdered.datagridOrdered.Rows(Form1.Row_Index).Cells(0).Value //<- here
Dim value2 As Object = FormOrdered.datagridOrdered.Rows(Form1.Row_Index).Cells(1).Value //<- here
TBJobNumber.Text = CType(value1, String)
TBFloor.Text = CType(value2, String)
...
...
End Sub
or add a module and add the Row_Index there. You can use it then as is
Private Sub BuildName_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim value1 As Object = FormOrdered.DataGridView1.Rows(Row_Index).Cells(0).Value
Dim value2 As Object = FormOrdered.DataGridView1.Rows(Row_Index).Cells(1).Value
TBJobNumber.Text = CType(value1, String)
TBFloor.Text = CType(value2, String)
...
...
End Sub
I am trying to display sql database table data in a list view in my vb application. I have used the following code
Public Class Form1
Dim conn As SqlClient.SqlConnection
Dim cmd As SqlClient.SqlCommand
Dim da As SqlClient.SqlDataAdapter
Dim ds As DataSet
Dim itemcoll(100) As String
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.ListView1.View = View.Details
Me.ListView1.GridLines = True
conn = New SqlClient.SqlConnection("Data Source=AYYAGARI-PC\WINCC;Initial Catalog=anand;Integrated Security=True")
conn.Open()
Dim strQ As String = String.Empty
strQ = "SELECT * FROM [anand].[dbo].[WINCC] ORDER BY [dateandtime]"
cmd = New SqlClient.SqlCommand(strQ, conn)
da = New SqlClient.SqlDataAdapter(cmd)
ds = New DataSet
da.Fill(ds, "Table")
Dim i As Integer = 0
Dim j As Integer = 0
' adding the columns in ListView
For i = 0 To ds.Tables(0).Columns.Count - 1
Me.ListView1.Columns.Add(ds.Tables(0).Columns(i).ColumnName.ToString())
Next
'Now adding the Items in Listview
Try
Call Timer1_Tick(sender, e)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
For Each i As ListViewItem In ListView1.SelectedItems
ListView1.Items.Remove(i)
Next
Try
For i = 0 To ds.Tables(0).Rows.Count - 1
For j = 0 To ds.Tables(0).Columns.Count - 1
itemcoll(j) = ds.Tables(0).Rows(i)(j).ToString()
Next
Dim lvi As New ListViewItem(itemcoll)
Me.ListView1.Items.Add(lvi)
Next
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
The problem with the above code is that whenever i update the table data in sql (inserting or deleting data), the same doesnt get updated in list view. Kindly help me out with this.
Me.ListView1.View = View.Details
Me.ListView1.GridLines = True
conn = New SqlClient.SqlConnection("Data Source=AYYAGARI-PC\WINCC;Initial Catalog=anand;Integrated Security=True")
conn.Open()
Dim strQ As String = String.Empty
strQ = "SELECT * FROM [anand].[dbo].[WINCC] ORDER BY [dateandtime]"
cmd = New SqlClient.SqlCommand(strQ, conn)
da = New SqlClient.SqlDataAdapter(cmd)
ds = New DataSet
da.Fill(ds, "Table")
Dim i As Integer = 0
Dim j As Integer = 0
' adding the columns in ListView
For i = 0 To ds.Tables(0).Columns.Count - 1
Me.ListView1.Columns.Add(ds.Tables(0).Columns(i).ColumnName.ToString())
Next
'Now adding the Items in Listview
Try
Call Timer1_Tick(sender, e)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
Try to add this code again to your button which made insert or update.
UPDATE
I give you another tips, that wont make your code so long and wasted memory or capacity..
Try to insert all the code to new sub, e.g :
private sub mycode
msgbox("Hello World")
end sub >> This code won't work when you debug, cause it just like a stored code, so need to be called to make it work
Private sub Form_load...... > E.g this is your form load code
call mycode >> Called the code above
end sub >> when you debug, your form will auto called the mycode