I want to make it so a new datatable gets created based on what rows the user selects in the datagridview, however I keep getting an error saying Unable to cast object of type 'System.Windows.Forms.DataGridViewRow' to type 'System.Windows.Forms.DataGridView
I have no clue what this means, and I was hoping I could get some help.
Private Function getCoordinates()
Dim dt2 As New DataTable
'Dim r As DataRow
Dim n As Integer
Dim selectedItems As DataGridViewSelectedRowCollection = dgv.SelectedRows
dt = dgv.DataSource
dgv.SelectionMode = DataGridViewSelectionMode.FullRowSelect
dgv.MultiSelect = True
dt2.Columns.Add("Position")
Try
For Each selectedItem As DataGridView In selectedItems
dt2.Rows.Add(n)
dt2.Rows(n)("Position") = dt.Rows.Item(n)("Mouse Position")
Next
Catch ex As Exception
MsgBox("Error", MsgBoxStyle.Exclamation, "Error!")
End Try
Return dt2
Replace
For Each selectedItem As DataGridView In selectedItems
dt2.Rows.Add(n)
dt2.Rows(n)("Position") = dt.Rows.Item(n)("Mouse Position")
Next
With
For Each selectedItem As DataGridViewRow In selectedItems
dt2.Rows.Add(selectedItem)
' dt2.Rows(n)("Position") = dt.Rows.Item(n)("Mouse Position")
Next
selectedItems contains a list of DataGridViewRow objects, not DataGridViews. Update to the following:
For Each selectedItem As DataGridViewRow In selectedItems
Related
Basically, I wan't the user to be able to type into datagridViewComboboxColumn
and if there is no match it will automatically save the text into the database, update the BindingSource and select the item.
Heres what I have so far.
The bindingsource:
With acctTitleCombo6
.AutoComplete = True
Try
.DataSource = ds4
.DisplayMember = "desc_description"
.ValueMember = "desc_id"
.DataPropertyName = "desc_id"
.AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End With
Changing combobox style to dropdown in EditingControlShowing:
Dim comboBoxColumn As DataGridViewComboBoxColumn = DataGridView2.Columns(0)
If (DataGridView2.CurrentCellAddress.X = comboBoxColumn.DisplayIndex) Then
Dim cb As ComboBox = TryCast(e.Control, ComboBox)
If (cb IsNot Nothing) Then
cb.DropDownStyle = ComboBoxStyle.DropDown
End If
End If
Checking if typed text is already in the source item (CellValidating event).
Dim comboBoxColumn As DataGridViewComboBoxColumn = DataGridView2.Columns(0)
cs2.Open()
Dim comm, comm2, comm3 As New MySqlCommand
comm.Connection = cs2
Dim msgAddDesc As String = "Your description is currently not in the list." & vbNewLine & _
"Would you like to add '"
If (e.ColumnIndex = comboBoxColumn.DisplayIndex) And Not String.IsNullOrWhiteSpace(e.FormattedValue) Then
Dim itemIE As IEnumerator = comboBoxColumn.Items.GetEnumerator
itemIE.Reset()
Dim thisItem As DataRowView
Dim exist As Boolean = False
While itemIE.MoveNext()
thisItem = CType(itemIE.Current(), DataRowView)
Dim valueMember As Object = thisItem.Row.ItemArray(0)
Dim displayMember As Object = thisItem.Row.ItemArray(1)
If displayMember.ToString = e.FormattedValue Then
exist = True
End If
End While
If exist = False Then
If MessageBox.Show(msgAddDesc & e.FormattedValue & "' to the list?", "Does not exist", _
MessageBoxButtons.YesNo) = Windows.Forms.DialogResult.Yes Then
comm.CommandText = "INSERT INTO ref_description(desc_description) " & _
"VALUES(#description)"
With comm.Parameters
.Add("#description", MySqlDbType.VarChar).Value = e.FormattedValue
End With
comm.ExecuteNonQuery()
comm.Parameters.Clear()
End If
End If
End If
cs2.Close()
Now, whenever I add a new item into the database, this error comes up but sometimes it doesn't:
The following exception occurred in the DataGridView:
System.FormatException: Value '' cannot be converted to type 'System.String'.
at System.Windows.Forms.DataGridViewComboBoxCell.ParseFormattedValue(Object formattedValue, DataGridViewCellStyle cellStyle, TypeConverter formattedValueTypeConverter, TypeConverter valueTypeConverter)
at System.Windows.Forms.DataGridView.PushFormattedValue(DataGridViewCell& dataGridViewCurrentCell, Object formattedValue, Exception& exception)
Another question is, how can I update the combobox after I add the new item into the database, then I also want to automatically select the new item when the user press enter or tab (only when there's a new item added into the database).
I'm not sure, if I can help. However, the error comes from DataGridView, not combo. I suspect, that you update the datagridview at the same time (as you try to update the combo), which will not work. I think you need to finish cell editing first (incl. validation), then you can update the datagridview. I'd try to move it to CellEndEdit() event.
how can I update the combobox: I don't see the code, how you load the ComboBox in the first place.
Usually, you just update related dataset and re-assign it to ComboBox.DataSource, or you can use databinding (no need to update then, but one usually uses it if in need of more binding features).
Private Sub LoadUpdateSubListCombo()
Dim cmdText as String
cmdText = "SELECT ID,SubName FROM SubmarinesTable "
Dim ds as DataSet
ds = MyDataAccessLayer.GetQueryResults(cmdText)
Dim SubDT As DataTable = ds.Tables(0).DefaultView
cb3.DataSource = SubDT
cb3.ValueMember = "ID"
cb3.DisplayMember = "SubName"
End Sub
...where cb3 is a ComboBox...
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 need to get the information that is in each cell located in the datagrid view of the rows that the user selects. I have the selecting rows down, I just need help with getting the information in the cell. Right now it just returns as DataGridVewRow { Index=7} when the data is really a string. Here is my function
Private Function getCoordinates()
Dim dt As New DataTable
Dim dt2 As New DataTable
'Dim r As DataRow
Dim n As Integer = 0
Dim selectedItems As DataGridViewSelectedRowCollection = dgv.SelectedRows
dt = dgv.DataSource
dgv.SelectionMode = DataGridViewSelectionMode.FullRowSelect
dgv.MultiSelect = True
Dim i = dgv.CurrentRow.Index
dt2.Columns.Add("Position")
Try
If selectedItems Is Nothing Then
For n = 0 To dt.Rows.Count - 1
dt2.Rows.Add(n)
dt2.Rows(n)("Position") = dt.Rows.Item(n)("Mouse Position")
Next
Else
For Each selectedItem As DataGridViewRow In selectedItems
dt2.Rows.Add(selectedItem)
dt2.Rows(selectedItem.Index)("Position") = dt.Rows.Item(selectedItem.Index)("Mouse Position")
Next
End If
Catch ex As Exception
MsgBox("Error", MsgBoxStyle.Exclamation, "Error!")
End Try
Return dt2
End Function
You get the text of the cells via the DataGridViewRow's Cells property. The following example would get the text from the first cell in each selected row:
Dim strContents As String = String.Empty
For Each selectedItem As DataGridViewRow In selectedItems
strContents += " First Cell's Text: " & selectedItem.Cells(0).Text
Next
I am using this function to create datatable from gridviews. It works fine with Gridviews with AutoGenerateColumns = False and have boundfields or template fileds. But if I use it with Gridviews with AutoGenerateColumn = True I only get back an empty DataTable. Seems Gridview viewstate has been lost or something. Gridview is binded on PageLoad with If Not IsPostback. I can't think of anything else to make it work. Hope someone can help me.
Thanks,
Public Shared Function GridviewToDataTable(gv As GridView) As DataTable
Dim dt As New DataTable
For Each col As DataControlField In gv.Columns
dt.Columns.Add(col.HeaderText)
Next
For Each row As GridViewRow In gv.Rows
Dim nrow As DataRow = dt.NewRow
Dim z As Integer = 0
For Each col As DataControlField In gv.Columns
nrow(z) = row.Cells(z).Text.Replace(" ", "")
z += 1
Next
dt.Rows.Add(nrow)
Next
Return dt
End Function
Slight modification to your function above. If the autogenerate delete, edit or select button flags are set, the values for the fields are offset by one. The following code accounts for that:
Public Shared Function GridviewToDataTable(ByVal PassedGridView As GridView, ByRef Error_Message As String) As DataTable
'-----------------------------------------------
'Dim Tbl_StackSheets = New Data.DataTable
'Tbl_StackSheets = ReportsCommonClass.GridviewToDataTable(StackSheetsGridView)
'-----------------------------------------------
Dim dt As New DataTable
Dim ColInd As Integer = 0
Dim ValOffset As Integer
Try
For Each col As DataControlField In PassedGridView.Columns
dt.Columns.Add(col.HeaderText)
Next
If (PassedGridView.AutoGenerateDeleteButton Or PassedGridView.AutoGenerateEditButton Or PassedGridView.AutoGenerateSelectButton) Then
ValOffset = 1
Else
ValOffset = 0
End If
For Each row As GridViewRow In PassedGridView.Rows
Dim NewDataRow As DataRow = dt.NewRow
ColInd = 0
For Each col As DataControlField In PassedGridView.Columns
NewDataRow(ColInd) = row.Cells(ColInd + ValOffset).Text.Replace(" ", "")
ColInd += 1
Next
dt.Rows.Add(NewDataRow)
Next
Error_Message = Nothing
Catch ex As Exception
Error_Message = "GridviewToDataTable: " & ex.Message
End Try
Return dt
End Function
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)