I want get data from 1 row of a DataGridView, I select to my textbox
this is my code,
Private Sub DataGridView1_CurrentCellChanged(sender As Object, e As EventArgs) Handles DataGridView1.CurrentCellChanged
Dim dColums(0) As DataColumn
dColums(0) = dsetmember.Tables("member").Columns(0)
dsetmember.Tables("member").PrimaryKey = dColums
'MessageBox.Show(DataGridView1.CurrentRow.Index, 1)
If DataGridView1.CurrentRow.Index = -1 Then
txtNamaMember.Text = ""
txtKodeMember.Text = ""
txtNoHP.Text = ""
Else
Dim dr As DataRow = dsetmember.Tables("member").Rows.Find(DataGridView1.Item(DataGridView1.CurrentRow.Index, 0))
txtKodeMember.Text = dr(0)
End If
End Sub
I get this error, nullreferenceException was unhandled
Object reference not set to an instance of an object.
thx b4.
Try change this part ..
If DataGridView1.CurrentRow.Index = -1 Then
txtNamaMember.Text = ""
txtKodeMember.Text = ""
txtNoHP.Text = ""
Else
Dim dr As DataRow = dsetmember.Tables("member").Rows.Find(DataGridView1.Item(DataGridView1.CurrentRow.Index, 0))
txtKodeMember.Text = dr.item(0)
End If
The error happens in the assigniment of dr(0) to the textbox.Text.
This means that the Find method has not found the value passed and so the result is NULL.
Trying to reference dr(0) when dr is Nothing is like writing NOTHING(0) and, of course, this will fail
Dim dr As DataRow = dsetmember.Tables("member").Rows.Find(DataGridView1.Item(DataGridView1.CurrentRow.Index, 0))
if dr IsNot Nothing then
txtKodeMember.Text = dr(0)
else
MessageBox.Show("Value not found")
End If
Also remember that the Find method search the value passed on the primary key column(s) of the table. Are you sure that the first column of the grid contains the primary keys?
Related
I have a DataGridView (DGV) that I am adding items to from a SQLite DB MANUALLY
My setting for the Selection Mode have been CellSelect and FullRowSelect may have tried others
The Errors and Issues are varied depending on where the user clicks on the DGV
The code as it is now the Errors only occur when an empty Column under Header PID is selected
And when the Column Header PID is selected See Posted Image
I have included the ERRORS as comments in the code
One of the issues I would like to FIX is to disable all sorting on all Columns
The Data added to the DGV is a primary key which is a Integer PID
And some text which is a NVARCHAR(2048) this text is from a RichTextBox
The two biggest issue to fix is preventing the ERRORS YES those are the Questions
Private Sub PopulateDGV()
For Each header As DataGridViewHeaderCell In dgvOne.Rows
'header.SortMode = DataGridViewColumnHeaderCell.NotSortable
Next
'The code Above NOT Working
'ERRORS
'System.InvalidOperationException 'Column's SortMode cannot be set to Automatic
'While the DataGridView control's SelectionMode is set to ColumnHeaderSelect.'
'Your app has entered a break state, but there is no code to show because all
'threads were executing external code (typically system Or framework code).
'dgvOne = DataGridViewColumnSortMode.NotSortable
Dim str2 As String
Dim s1 As Integer
Dim dbName As String = "Word.db"
Dim conn As New SQLiteConnection("Data Source =" & dbName & ";Version=3;")
Dim valuesList As ArrayList = New ArrayList()
'Read from the database
Dim cmd As SQLiteCommand = New SQLiteCommand("Select * FROM ParentTable", conn)
conn.Open()
Dim rdr As SQLite.SQLiteDataReader = cmd.ExecuteReader
'Set Design of the DataGridView
dgvOne.DefaultCellStyle.Font = New Font("Tahoma", 10)
dgvOne.ColumnCount = 2
dgvOne.Columns(0).Width = 60
dgvOne.Columns(1).Width = 420
'Set Col Header Size Mode = Enabled
'Set Col Header Default Cell Styles DO in Properties
dgvOne.ColumnHeadersHeight = 34
'DGV Header Names
dgvOne.Columns(0).Name = "PID"
dgvOne.Columns(1).Name = "Entry Data"
'Read from DB Table add to DGV row
While rdr.Read()
valuesList.Add(rdr(1)).ToString()
lbOne.Items.Add(rdr(1)).ToString()
s1 = rdr(0).ToString
str2 = rdr(1)
dgvOne.Rows.Add(s1, str2)
End While
'Add Blank rows to DGV
For iA = 1 To 4
dgvOne.Rows.Add(" ")
Next
rdr.Close()
conn.Close()
End Sub
Private Sub dgvTwo_CellMouseClick(sender As System.Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles dgvOne.CellMouseClick
If (e.RowIndex = -1) Then
MessageBox.Show("No Clicking Here")
Return
End If
If dgvOne.CurrentCell.Value Is Nothing Then
tbMessage.Text = "NO Data Here"
Return
ElseIf e.RowIndex >= 0 Then
tbMessage.Text = e.RowIndex
Dim str2 As String
Dim s2 As String
Dim row As DataGridViewRow = dgvOne.Rows(e.RowIndex)
s2 = row.Cells(0).Value.ToString
str2 = row.Cells(1).Value.ToString
strB = str2
rtbEnter.Text = strB
'ERRORS
'System.NullReferenceException
'HResult = 0x80004003
'Message = Object reference Not Set To an instance Of an Object.
'Source = TestSQL
'StackTrace:
'at TestSQL.frmThree.dgvTwo_CellMouseClick(Object sender, DataGridViewCellMouseEventArgs e) in C:\Users\Dwight\source\repos\TestSQL\TestSQL\frmThree.vb:line 117
End If
End Sub
To prevent sorting on columns, which appears to be your main question, do the following:
dgvOne.Columns(0).SortMode = DataGridViewColumnSortMode.NotSortable
dgvOne.Columns(1).SortMode = DataGridViewColumnSortMode.NotSortable
You also need to guard against null values in cells. So in the "CellMouseClick" event, add something like this:
If row.Cells(1).Value IsNot Nothing Then
str2 = row.Cells(1).Value.ToString
End If
#Brian M Stafford
Thanks for getting us headed in the correct direction Vector this is easy to figure out if someone would have shared a little information GREAT Questions's guess your were saving bytes
Because you only have three (3) Columns here are their names and positions in the DGV
Col -1 Col 0 Col 1 and YES they go Left to Right
Just So No One Gets Confused Rows go Top to Bottom
Row 0
Row 1
So all you really needed was one more test that delt with ColumnIndex
This code only permits clicking on Column 1 provided it has text in that CELL
Just manipulate the tests and you can provide the user additional selections
Public Sub dgvTwo_CellMouseClick(sender As System.Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles dgvOne.CellMouseClick
If e.RowIndex = -1 Or e.ColumnIndex = -1 Then
'tbMessage.Text = "Col " & e.ColumnIndex & " ROW " & e.RowIndex
tbMessage.Text = "No Clicking Here"
Return
End If
If dgvOne.CurrentCell.Value Is Nothing Then
tbMessage.Text = "NO Data Here"
Return
End If
Dim s3 As Integer
s3 = e.ColumnIndex
If s3 = 0 Then
'tbMessage.Text = "S3 " & e.ColumnIndex
tbMessage.Text = "No Clicking Here"
Return
End If
Dim row As DataGridViewRow = dgvOne.Rows(e.RowIndex)
Dim col As DataGridViewColumn = dgvOne.Columns(e.ColumnIndex)
If e.RowIndex >= 0 And e.ColumnIndex <> -1 Then
tbMessage.Text = "Data Sent to RTB"
Dim str2 As String
str2 = row.Cells(1).Value.ToString
rtbEnter.Text = str2
End If
End Sub
After reading all the nice answers and looking for a way to accomplish my multitude of issues and a lot of trial and error here is one way to deal with preventing the user from clicking on various location on the DataGridView
Public Sub dgvTwo_CellMouseClick(sender As System.Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles dgvOne.CellMouseClick
If e.RowIndex = -1 Or e.ColumnIndex = -1 Then
'tbMessage.Text = "Col " & e.ColumnIndex & " ROW " & e.RowIndex
tbMessage.Text = "No Clicking Here"
rtbEnter.Clear()
Return
End If
Dim str1 As String
Dim str2 As String
Dim s1 As Integer
Dim row As DataGridViewRow = dgvOne.Rows(e.RowIndex)
str1 = dgvOne.CurrentRow.Cells(0).Value.ToString
If str1 IsNot " " Then
If str1 Is " " Then
Return
End If
tbMessage.Text = "Text Sent to RTB"
s1 = row.Cells(0).Value
'Dim strInt As String
gv_passInt = s1.ToString
str2 = row.Cells(1).Value.ToString
rtbEnter.Text = str2
gv_passStr = str2
Return
End If
rtbEnter.Clear()
tbMessage.Text = "No Data Here"
End Sub
I read several article relating to setting the value of a combobox however I still couldn't come up with a solution.
Below is a basic example of what I want to do and in the comments is exactly what I want to do. Any help is appreciated.
Public Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Dim dt As New DataTable
dt.Columns.Add("ID")
dt.Columns.Add("Name")
dt.Columns.Add("Value")
dt.Columns(0).AutoIncrement = True
For i As Integer = 0 To 20
Dim R As DataRow = dt.NewRow
R("Name") = "Test" & Date.Now & "" & i
If i = 2 Or i = 5 Or i = 6 Or i = 8 Or i = 10 Then
R("Value") = "yes"
Else
R("Value") = "no"
End If
dt.Rows.Add(R)
DataGridView1.DataSource = dt
Next
DataGridView1.ReadOnly = False
Dim cmb As New DataGridViewComboBoxColumn()
cmb.HeaderText = "Select Data"
cmb.Name = "cmb"
cmb.MaxDropDownItems = 2
cmb.Items.Add("True")
cmb.Items.Add("False")
DataGridView1.Columns.Add(cmb)
For Each dr As DataRow In dt.Rows
If dr("Name").ToString = "Test" Then
'set the combo box value to True
Else
'set the combobox value to False
End If
Next
End Sub
You can set the value by setting the Cells.Value...
DataGridView1.Rows(whatrowdoyouwant).Cells("cmb").Value = True
On another note, you set the DataSource to the DataGridView, but loop through the DataTable. If you want to set each row in the DataGridView this wont work.
For Each dr As DataRow In dt.Rows
If dr("Name").ToString = "Test" Then
'set the combo box value to True
Else
'set the combobox value to False
End If
Next
You would need to loop through each DataGridViewRow in the DataGridView and set the ComboBox value. For example...
For i As Integer = 0 To DataGridView1.Rows.Count - 1
If DataGridView1.Rows(i).Cells("Name").Value.ToString = "Test" Then
DataGridView1.Rows(i).Cells("cmb").Value = True
Else
DataGridView1.Rows(i).Cells("cmb").Value = False
End If
Next
The procedures below allowed me to delete several records at once by checking the checkbox on my datagrid. The procedure was written on ASP.net but now I am using a winform on VB.net.
I have a datagrid with column name "Delete" where the checkboxes are located. The user would check
the records it wants to delete and the would delete those records. I use the "Ticket Number" column values as the parameter for my query.
The issue I have is that since was written for ASP.Net, I cannot find how the winform VB.net equivalent for this line:
Dim chkDelete As CheckBox = DirectCast(grdRoster.Rows(i).Cells(0).FindControl("Delete_Row"), CheckBox)
FindControl is not a member of System.Windows.Forms.DataGridViewCell. Plus I am pretty sure that the whole line is wrong since the checkboxes
are located on a datagrid column set as ColumnType: DataGridViewCheckBoxColumn and are not really individual controls.
How can I get the same result on a winform? Here is my entire code.
Private Sub btnDelete_Click(sender As Object, e As EventArgs) Handles btnDelete.Click
'Create String Collection to store
'IDs of records to be deleted
Dim ticketNumberCollection As New StringCollection()
Dim strTicketNumber As String = String.Empty
'Loop through GridView rows to find checked rows
For i As Integer = 0 To grdRoster.Rows.Count - 1
Dim chkDelete As CheckBox = DirectCast(grdRoster.Rows(i).Cells(0).FindControl("Delete_Row"), CheckBox)
If chkDelete IsNot Nothing Then
If chkDelete.Checked Then
strTicketNumber = grdRoster.Rows(i).Cells(1).ToString
ticketNumberCollection.Add(strTicketNumber)
End If
End If
Next
'Call the method to Delete records
DeleteMultipleRecords(ticketNumberCollection)
' rebind the GridView
grdRoster.DataBind()
End Sub
' Sub to delete multiple records
' #param "idCollection" calls the string collection above
' and deletes the selected record separated by ","
Private Sub DeleteMultipleRecords(ByVal ticketNumberCollection As StringCollection)
Dim IDs As String = ""
'Create string builder to store
'delete commands separated by ,
For Each id As String In ticketNumberCollection
IDs += id.ToString() & ","
Next
Try
Dim strTicketID As String = IDs.Substring(0, IDs.LastIndexOf(","))
DataSheetTableAdapter.DeleteRecord(strTicketID)
Catch ex As Exception
Dim errorMsg As String = "Error in Deletion"
errorMsg += ex.Message
Throw New Exception(errorMsg)
Finally
Me.Close()
End Try
End Sub
for deleting multiple records from a data bound gridview you should create the DataGridViewCheckBoxColumn at run time
Dim chk As New DataGridViewCheckBoxColumn()
DataGridView1.Columns.Add(chk)
chk.HeaderText = "Select"
'then bind your datagridview with dataset
Dim sql As String = "SELECT * FROM table_name"
' Dim connection As New SqlConnection(connectionString)
conn.Open()
sCommand = New SqlCommand(sql, conn)
sAdapter = New SqlDataAdapter(sCommand)
sBuilder = New SqlCommandBuilder(sAdapter)
sDs = New DataSet()
sAdapter.Fill(sDs, "table_name")
sTable = sDs.Tables("table_name")
DataGridView1.DataSource = sDs.Tables("table_name")
'then traverse through each column and get the checked values
Try
DataGridView1.EndEdit()
For j = Me.DataGridView1.Rows.Count - 1 To 0 Step -1
If Not IsDBNull(DataGridView1.Rows(j).Cells(0).Value) Then
If DataGridView1.Rows(j).Cells(0).Value = True Then
check = True
If MessageBox.Show("Do you want to delete these records?", "Delete", MessageBoxButtons.YesNo) = DialogResult.Yes Then
For i = Me.DataGridView1.Rows.Count - 1 To 0 Step -1
If Not IsDBNull(DataGridView1.Rows(i).Cells(0).Value) Then
If DataGridView1.Rows(i).Cells(0).Value = True Then
'remove the checked columns and update datatable
DataGridView1.Rows.RemoveAt(i)
sAdapter.Update(sTable)
End If
End If
Next
Else
Return
End If
Else
End If
End If
Next
If check = False Then
MsgBox("Nothing Selected")
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
I am trying to check for multiple selections in a DataGridView with a For... Next Loop, but even though I have selected multiple rows, the only row with the property Selected=True is the first row in the selection. Is there a way around this?
MultiSelect is true on the DataGridView.
My code is as follows:
For Each dr As DataGridViewRow In dgv.Rows
If dr.Selected = True Then
intSelectedRow = dr.Index
SetTime("KeyEntry", dgv.Name, intSelectedRow)
End If
Next
Thanks
Try this:
Dim selectedItems As DataGridViewSelectedRowCollection = dgv.SelectedRows
For Each selectedItem As DataGridViewRow In selectedItems
'Add code to handle whatever you want for each row
Next
End Sub
Dim Message As String = String.Empty
Dim FNL As FinalRpt = New FinalRpt()
For Each ItemRow As DataGridViewRow In DGVItems.Rows
Dim ISSelected As Boolean = Convert.ToBoolean(ItemRow.Cells("MyChkBox").Value)
If ISSelected Then
Message &= Environment.NewLine
Message &= ItemRow.Cells("I_ID").Value.ToString()
Dim SelectedRow As Integer = DGVItems.Rows.GetRowCount(DataGridViewElementStates.Selected)
Dim RPTItemsDA As OleDbDataAdapter
Dim RPTItemsDS As DataSet
Dim I As Integer
For I = 0 To SelectedRow Step 1
RPTItemsDA = New OleDbDataAdapter("Select Distinct * From stkrpt Where I_ID = " & DGVItems.SelectedRows(I).Index.ToString() & "", DBConnect)
RPTItemsDS = New DataSet
RPTItemsDA.Fill(RPTItemsDS, "stkrpt")
FNL.DGVReport.DataSource = RPTItemsDS
FNL.DGVReport.DataMember = "stkrpt"
Next
FNL.MdiParent = MDIParent1
FNL.StartPosition = FormStartPosition.CenterScreen
FNL.WindowState = FormWindowState.Maximized
Me.Hide()
FNL.Show()
ISSelected = False
End If
Next
MessageBox.Show(Message)
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