I have a BindingSource bound to a DataTable.
I use the BS Filter and would like to iterate the filtered dataset of the DataTable using the Bindingsource.
I know I can do a MoveFirst and the MoveNext and each time using the BS.Position get the correct row in the underlying DataTable.
But how do I know when the sets ends? I'm sure there must be such a property, but what is it?
Private Sub BindDataGridView()
Dim count As Integer = 0
For count = 0 To EmployeeListBindingSource.Count - 1
Dim RowIndex As Integer = dataGrdView1.Rows.Add()
Dim row As DataRowView = DirectCast(EmployeeListBindingSource.Item(count), DataRowView)
dataGrdView1.Rows(RowIndex).Cells(0).Value = row.Item(1).ToString
dataGrdView1.Rows(RowIndex).Cells(2).Value = row.Item(0).ToString
Next
End Sub
Declare a row as:
Dim row As DataRowView = DirectCast(EmployeeListBindingSource.Item(count), DataRowView)
Then, access columns like:
row.Item(1).ToString
Compare it with if CompareStr <> row.Item(1).ToString then
I hope this helps.
BindingSource has Count property
Related
I am developing a small program to get the maximum of a specific column in a gridview (DevExpress), but I could not execute it as I wanted.
Can you support me in seeing where I have the error?
Dim cells() As GridCell = GridView2.GetSelectedCells()
Dim values As New List(Of Decimal)()
For i As Integer = 0 To GridView2.RowCount - 1
Dim value As Decimal = Convert.ToDecimal(GridView2.GetRowCellValue(cells(i).RowHandle, cells(i).Column))
values.Add(value)
Next i
values.Sort()
MsgBox(values.Max().ToString())
Regards.
With the built in DataGridView, the number of rows can be Rows.Count -2 because there is an extra row for the user to enter a new record. I have no idea if DevExpress works that way but it is worth a try.
For i As Integer = 0 To GridView2.RowCount - 2
If your GridView uses a DataTable as a DataSource, then the following code might help. If the DataTable is still available then just start with that. Otherwise extract it from the grid.
DataTable does not implement IEnumerable but there is an extension method to get the interface (.AsEnumerable).
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim dt = DirectCast(DataGridView1.DataSource, DataTable)
Dim maxValue = Aggregate r In dt.AsEnumerable
Into MaxID = Max(r("ID")) '"ID" is the name of a column
MessageBox.Show(maxValue.ToString)
End Sub
Same thing for Min just change Max to Min.
Calculate Total Summary for Grid Column
gridView1.Columns("UnitsInStock").Summary.Add(DevExpress.Data.SummaryItemType.Average, "UnitsInStock", "Avg={0:n2}")
gridView1.Columns("UnitsInStock").Summary.Add(DevExpress.Data.SummaryItemType.Sum, "UnitsInStock", "Sum={0}")
Dim item As GridColumnSummaryItem = New GridColumnSummaryItem(DevExpress.Data.SummaryItemType.Max, "UnitsInStock", "Max={0}")
gridView1.Columns("UnitsInStock").Summary.Add(item)
Devexpress Documentation:
https://documentation.devexpress.com/WindowsForms/DevExpress.XtraGrid.Columns.GridColumn.Summary.property
https://documentation.devexpress.com/WindowsForms/9677/Controls-and-Libraries/Data-Grid/Examples/Summaries/How-to-Calculate-Single-Total-Summary-for-Grid-s-Column
I have some code that is intended to:
1. Loop through a datagrid that is user populated
2. Search an access database using the input criteria
3. Return the results as a datatable
4. Merge additional results to that datatable
5. Bind the merged table results to a DataGridView
The query works, results return as expected with a single value search. The query will also return one of the two test values if I use the user input DataGridView. However, it will not combine the two results before outputting to the results_DataGridView. I have also tried using .Fill from the adapter to add onto my temp table and use that as the datasource.
Option Strict On
Dim dt_TempTable As New DataTable
Dim dt_ContentsTable As New DataTable
Dim SerialNumbers As New List(Of String)
Dim PanelIDs As New List(Of String)
Dim MultiSearch As Boolean
Private Sub bgwk_data_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles bgwk_data.DoWork
If Not (MultiSearch) Then
Retrieveinfo(Me.txt_SerialNumber.Text, Me.txt_PanelID.Text) 'Local
Else
Dim arrSN As String() = SerialNumbers.ToArray()
Dim arrPID As String() = PanelIDs.ToArray()
For i = 0 To arrSN.Count - 1
If i > 0 Then
Retrieveinfo(arrSN(i), arrPID(i)) 'Local - Run query and create a new temp table of results
dt_ContentsTable.Merge(dt_TempTable) 'Merge new temp table to current contents table
Else
dt_ContentsTable = Retrieveinfo(arrSN(i), arrPID(i)) 'Return the original temp table to the contents table (datagridview datasource)
End If
Next
End If
End Sub
'Gets the Data by SerialNumber and saves it to dt_TempTable to be bound afterwards
Private Function Retrieveinfo(SerialNumber As String, PanelID As String) As DataTable
Dim ds As New datasource
Dim tblAdapt As New datasourceTableAdapters.toHTML_SPC_DataTableAdapter
tblAdapt.GetData(dt_TempTable, SerialNumber, PanelID)
Return dt_TempTable 'Return the table
End Function
'Updates dg_data with the datatable from Retrieveinfo and refreshes the form
Private Sub bgwk_dataRunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles bgwk_data.RunWorkerCompleted
'Unlocks ability to search new things
Me.txt_PanelID.ReadOnly = False
Me.txt_SerialNumber.ReadOnly = False
Me.dg_data.ReadOnly = False
'Binds the backgroundworker results to the datagridview
Me.dg_data.DataSource = Nothing
Me.dg_data.DataSource = dt_ContentsTable
Me.dg_data.Refresh()
Me.Refresh()
End Sub
I understand that merge can be used on DataTables, but perhaps this is incorrect usage?
I'd go with a condition in the multi-search loop:
If dt_ContentsTable.Rows.Count = 0 Then
dt_ContentsTable = dt_TempTable.Clone()
End If
dt_ContentsTable.Merge(dt_TempTable)
This way, the first time, its at least creating the columns of the dt_ContentsTable.
I also don't see any code in the single search where dt_ContentsTable is assigned. So, in the single search, I recommend you assign dt_ContentsTable to dt_TempTable.
I know, how to increase integer, string by for statement
but I want know how to change the name by 'for ~next' statement.
For example,
Dim row_sort1 As DataTable = rows1.CopyToDataTable
Dim row_sort2 As DataTable = rows2.CopyToDataTable
Dim row_sort3 As DataTable = rows3.CopyToDataTable
Dim row_sort4 As DataTable = rows4.CopyToDataTable
Dim row_sort5 As DataTable = rows5.CopyToDataTable
Dim row_sort6 As DataTable = rows6.CopyToDataTable
Dim row_sort7 As DataTable = rows7.CopyToDataTable
I had coding like this,, bad cording So I want change by 'for ~next' statement.
I want increase the datatable name's number (1~7)
how can reflect in this coding. I want fix my coding more simple and useful.
I need your help
thank you
I assume you have a Collection of Rows which is your master where you want to copy from.
I have a similiar approach like OSKM. Better use a list collection than an array.
To access tables afterwards in the collection you can use Linq.
' Given master rowcollection
Dim masterRow As EnumerableRowCollection(Of DataRow)
' Empty table collection
Dim tableList As New List(Of DataTable)
For t As Integer = 0 To 6
' copy Master to a new table
Dim newTable As DataTable = masterRow.CopyToDataTable()
' give the new table a name
newTable.TableName = "Table" & t.ToString
' Add new table to collection
tableList.Add(newTable)
Next
' Access a certain table (i.e. Table5) using Linq
Dim table5 As DataTable = tableList.FirstOrDefault(Function(x) x.TableName = "Table5")
If i understand your question correct the following might help.
'Note your datatables will be named Datatable0 to Datatable6
Dim DTs(6) As DataTable
For i = 0 To 6
DTs(i) = New DataTable
DTs(i).TableName = "Datatable" & i
Next
There is probably better ways but this will work!
I call into a function which runs a query into SQLServer and returns a DataTable with multiple columns. I want the data from the DataTable to change rows according to the selected item in the combobox.
Dim dt As New DataTable
Dim rInt As New Int32
dt = subGetDB()
rInt = ComboBox1.SelectedIndex
Textbox1.Text = dt.Rows(rInt)("description").ToString()
TextBox2.Text = dt.Rows(rInt)("accountFilter").ToString()
Am I on the right track with this so far?
Yes ... but you need to put all of the code above into the SelectedValueChanged event for the ComboBox1 object.
I have a DataGridView with two DataGridViewComboBoxColumns. I want to use the selected item in the first column to trigger a re-population of the items in the second column, on a per-row basis.
Here's the code I have so far. "addlInfoParentCat" identifies the first column, and currentRow.Cells.Item(1) is the DataGridViewComboBoxCell that I want to re-populate. ExtEventAdditionalInfoType is a type I defined that contains the string/value pairs.
Private Sub dgvAdditionalInfo_CellValueChanged(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles dgvAdditionalInfo.CellValueChanged
Dim currentCell As DataGridViewCell
currentCell = Me.dgvAdditionalInfo.CurrentCell
If Not currentCell Is Nothing Then
If currentCell.OwningColumn.DataPropertyName = "addlInfoParentCat" Then
Dim parentTypeID As Integer = currentCell.Value
Dim currentRow As DataGridViewRow = Me.dgvAdditionalInfo.CurrentRow
Dim subtypeCell As DataGridViewComboBoxCell = currentRow.Cells.Item(1)
Dim theChildren As New List(Of ExtEventAdditionalInfoType)
theChildren = Custom_ExtEventAdditionalInfoType.GetChildrenOfThisParentOrderByTypeName(parentTypeID)
subtypeCell.DataSource = Nothing
subtypeCell.DataSource = theChildren
subtypeCell.DisplayMember = "ExtEventAdditionalInfoTypeDescr"
subtypeCell.ValueMember = "ID_ExtEventAdditionalInfoType"
End If
End If
End Sub
Basically what I see is that the binding works great the first time around. When I select a item in the first column, it populates the items correctly in the second. I can add rows to the DataGridView and repeat the process.
The problem comes when I try to change the first-column item after the second column has already been bound. I get an endless string of dialog boxes with the following:
System.ArgumentException: DataGridViewComboBoxCell value is not valid.
Any idea why this is happening? Thanks in advance!
UPDATE CodeByMoonlight's suggestion appears to work.
I clear the DataGridViewComboBoxCell's value before re-binding:
....
subtypeCell.DataSource = Nothing
subtypeCell.Value = Nothing 'here's the change
subtypeCell.DataSource = theChildren
....
Well, it looks like as soon as you remodify the first combo's value, you're invalidating the binding and datasource you used to populate the second combo, causing all the errors.