I am working with only one 2D array, i.e., x(,) As Object, and it is based on the rectangular datafile opened by a user. The contents of x(,) is mostly numeric single- or double-precision reals and integers. So, the array can have dimensions from x(100,100) to e.g. x(100000,1000).
The datagridview is created dynamically and is updated via a call to a DGVCREATE class.
As an attempt to decrease the sizer of the datasource used by the datagridview, there is an AddHandler for datagridview1.scroll, so that when the user scrolls the datagridview, the upper left cell row and column ar epicked off, and then an attempt is made to add the next 20 columns and next 50 rows from the x(,) array into the DataTable, which assumingly updates the data shown in the datagridview. This is not working however.
One question, If I fill the DataTable with the entire array that is input by the user, how can datagridview1 be set up so that only, say 50 rows and 20 columns are added to the visible range. Without the scrolling addhandler to pick off where the user is in the array, and when stuffing the entire array into DataTable, this code works fine, but it just takes a long time to update the DataTable when adding columns following a computational update which requires addition of more fields. In other words, when there is e.g. 1000 rows and 50 fields in the DataTable, and another 20 columns are added to x(,) [i.e., Redim Preserve x(rows,50+20)], and then DataTable is updated, it takes a long time to add the additional 20 columns to DataTable when it already has 1000 rows and 50 columns.
'In a global module:
Public MainDataTable As New DataTable
Public FieldType() As Byte ' Byte array to denote the type of field (object, double, long, string, etc.)
Sub showdgv()
Dim x(1000, 100) As Object
Dim columnheaders(100) As String
Dim rowheaders(1000) As String
Dim fieldnames(100) As String
Dim rownames(1000) As String
For i as Integer = 0 To 999
For j As Integer = 0 to 99
x(i, j) = Rnd()
Next
Next
'Dynamically create a datagridview
Dim datagridview1 As New DataGridView
Me.Controls.Add(datagridview1)
datagridview1.AutoSize = True
datagridview1.AutoResizeRows()
datagridview1.AutoResizeColumns()
datagridview1.ClearSelection()
DoubleBufferedDGV(datagridview1, True)
datagridview1.AutoResizeRowHeadersWidth(DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders)
Dim dgvColumnHeaderStyle As New DataGridViewCellStyle()
dgvColumnHeaderStyle.Alignment = DataGridViewContentAlignment.MiddleCenter
datagridview1.ColumnHeadersDefaultCellStyle = dgvColumnHeaderStyle
datagridview1.AllowUserToAddRows = False
datagridview1.ScrollBars = ScrollBars.Both
datagridview1.Refresh()
datagridview1.Dock = DockStyle.Fill
AddHandler datagridview1.Scroll, AddressOf Me.DGV1_Scroll
'Instantiate the class object to update the DGV by loading the DataTable with the contant of the array x(,)
Dim dgv As New DGVCREATE(datagridview1, x, columnheaders, rowheaders, FieldNames, RowNames)
End Sub
Public Class DGVCREATE
Dim x(,) As Object
Dim columnheaders() As String
Dim rowheaders() As String
Dim fieldnames() As String
Dim rownames() As String
Sub New(ByRef dgv As DataGridView, ByVal x(,) As Object, ByVal columnheaders() As String, ByVal rowheaders() As String, ByVal FieldNames() As String, ByVal RowNames() As String)
Dim main As Form1 = CType(Application.OpenForms(0), Form1)
dgv.RowHeadersWidthSizeMode = DataGridViewRowHeadersWidthSizeMode.DisableResizing
GetResultsTable(x, columnheaders, rowheaders, FieldNames, RowNames)
'new trial code
dgv.AutoGenerateColumns = True
'Application.DoEvents()
dgv.DataSource = main.MainDataTable
dgv.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill
For i As Integer = 0 To main.MainDataTable.Columns.Count - 1
Dim Column As New DataGridViewTextBoxColumn
Column.Name = main.MainDataTable.Columns(i).ColumnName
Column.DataPropertyName = main.MainDataTable.Columns(i).ColumnName
Column.HeaderText = main.MainDataTable.Columns(i).ColumnName
Column.FillWeight = 70
Column.MinimumWidth = 70
dgv.Columns.Add(Column)
Next i
dgv.AutoSize = True
End Sub
Public Sub GetResultsTable(ByVal x(,) As Object, ByVal columnheaders() As String, ByVal rowheaders() As String, ByVal fieldnames() As String, ByVal rownames() As String)
Dim main As Form1 = CType(Application.OpenForms(0), Form1)
main.MainDataTable.Clear()
main.MainDataTable.Rows.Clear()
main.MainDataTable.Columns.Clear()
' Loop through all process names.
For j As Integer = dgvbegincol To dgvbegincol + 30 ' 0 To UBound(columnheaders) - 1
' The current process name.
' Add the program name to our columns.
Try
If FieldType(j + 1) = 0 Then main.MainDataTable.Columns.Add(fieldnames(j + 1), GetType(Object))
If FieldType(j + 1) = 1 Then main.MainDataTable.Columns.Add(fieldnames(j + 1), GetType(Double))
If FieldType(j + 1) = 2 Then main.MainDataTable.Columns.Add(fieldnames(j + 1), GetType(Long))
If FieldType(j + 1) = 3 Then main.MainDataTable.Columns.Add(fieldnames(j + 1), GetType(Long))
If FieldType(j + 1) = 4 Then main.MainDataTable.Columns.Add(fieldnames(j + 1), GetType(String))
Catch ex As Exception
If InStr(ex.Message, "column name") > 0 Then
Try
If FieldType(j + 1) = 0 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(Object))
If FieldType(j + 1) = 1 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(Double))
If FieldType(j + 1) = 2 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(Long))
If FieldType(j + 1) = 3 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(Long))
If FieldType(j + 1) = 4 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(String))
fieldnames(j + 1) = fieldnames(j + 1) & "_" & varsuffixvalue.ToString
Catch ex1 As Exception
If InStr(ex1.Message, "column name") > 0 Then
varsuffixvalue += 1
If FieldType(j + 1) = 0 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(Object))
If FieldType(j + 1) = 1 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(Double))
If FieldType(j + 1) = 2 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(Long))
If FieldType(j + 1) = 3 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(Long))
If FieldType(j + 1) = 4 Then main.MainDataTable.Columns.Add(fieldnames(j + 1) & "_" & varsuffixvalue.ToString, GetType(String))
fieldnames(j + 1) = fieldnames(j + 1) & "_" & varsuffixvalue.ToString
End If
End Try
End If
End Try
Do While main.MainDataTable.Rows.Count < UBound(rowheaders)
Dim myRow As DataRow
myRow = main.MainDataTable.NewRow()
main.MainDataTable.Rows.Add(myRow)
Loop
' Add each item to the cells in the column.
For i As Integer = dgvbeginrow To dgvbeginrow + 50 ' 0 To UBound(rowheaders) - 1
main.MainDataTable.Rows(i)(j) = If(x(i, j), CObj(DBNull.Value))
Next i
Next j
dgvThreadDone.Set()
End Sub
End Class
Sub DGV1_Scroll(sender As Object, e As ScrollEventArgs)
Dim x(,) As Object
Dim rowheaders() As String, columnheaders() As String
rowheaders = RowNames.Clone
columnheaders = FieldNames.Clone
For Each c In Me.Controls
If TypeOf (c) Is DataGridView Then
'Public dgvbeginrow, dgvendrow, dgvbegincol, dgvendcol As Integer
dgvbeginrow = c.FirstDisplayedCell.RowIndex
dgvbegincol = c.FirstDisplayedCell.ColumnIndex
Dim dgv As New DGVCREATE(c, x, columnheaders, rowheaders, FieldNames, RowNames)
End If
Next
End Sub
DataTable. – SSS