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.
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 a datatable (dsBrands) that I want to display in a datagridview. The combobox in the datagridview gets its selections from a different table(dsGroups). How do I show in the combobox the value that is currently stored in the dsBrands table? Below is my code that works except that the combobox is left blank. The combobox collection does populate correctly from dsGroups. The value that needs to be displayed in the combobox from dsBrands is in the collection. The --> is just to make the line stand out and not in the actual code.
Private Sub FillBrands()
Dim TransCount As Integer
Dim Group As String
If Not ds.Tables.Contains("dsBrands") Then Else ds.Tables("dsBrands").Clear()
conn.Open()
daBrands = New OleDbDataAdapter("Select * from Brands", conn)
daBrands.FillSchema(ds.Tables("dsBrands"), SchemaType.Source)
daBrands.Fill(ds, "dsBrands")
conn.Close()
dgv1.AutoGenerateColumns = False
bs1.DataSource = ds.Tables("dsBrands")
dgv1.DataSource = bs1
Dim colDisplay As New DataGridViewCheckBoxColumn
colDisplay.DataPropertyName = "Display"
colDisplay.HeaderText = "Include?"
colDisplay.Name = "Display"
colDisplay.Visible = True
Dim colGroupList As New DataGridViewComboBoxColumn
colGroupList.HeaderText = "Add to Group"
colGroupList.Name = "GroupList"
colGroupList.Visible = True
colGroupList.DataSource = ds.Tables("dsGroups")
--> colGroupList.DataPropertyName = "BGroup" 'BGroup is a field in dsBrands table.
dgv1.Columns.Add(colDisplay)
dgv1.Columns.Add(colBrand)
dgv1.Columns.Add(colGroup)
dgv1.Columns.Add(colGroupList)
End Sub
Just as when binding a regular ComboBox, you need to set the DisplayMember and ValueMember properties of your column. The DisplayMember specifies the column whose values get displayed and the ValueMember specifies the column whose values correspond to the grid data. ValueMember should specify the PK column of the table bound to the column that corresponds to the FK column of the table bound to the grid.
I am trying to programmatically set the value of a DataGridViewComboBox when I populate the grid, but I keep getting an error about not being able to sort the combobox - "ComboBox that has a DataSource set cannot be sorted. Sort the data using the underlying data model."
I am not trying to sort the data of the combobox, I am simply trying to set the value member when I perform the Rows.Add function.
EDIT** The entire column should contain the same combobox items, and is not row specific.
Public Sub LoadComboBox()
Dim comboBox = New Dictionary(Of Integer, String)
Try
//myStepTable = data ' SQL query to get ID and Step
For Each row As DataRow In myStepTable.Rows
comboBox.Add(row.Item("StepID"), row.Item("Step"))
Next
'colStep is the defined name of the combobox column
colStep.DataSource = New BindingSource(comboBox, Nothing)
colStep.DisplayMember = "Value"
colStep.ValueMember = "Key"
End Sub
Public Sub LoadGrid()
LoadComboBox()
myDataTable = data 'SQL query to get row data
For Each row As DataRow In myDataTable.Rows
dgvRecipeSteps.Rows.Add(row.Item("RowID"), row.Item("StepID"))
Next
End Sub
I am adding a tab page and datagridview to a Tab Control for every record in a datatable.
I would like to have a new Tab/DataGridView for each record (there will be ~3 for right now). I am declaring a new DataGridView D. How do I refer to these controls later?
I will want to do things like save changes in the datagridview to the database. Currently I can get the data on the screen and it looks good, but I believe I am not adding the DataGridView controls correctly because I keep re-using "D" as the control.
Dim dt As New DataTable
GetDataTable("SELECT * FROM aFeeTypes DescSeq", dt)
Dim i As Integer
'for each class in the datatable add a tab and a datagridview
For i = 0 To dt.Rows.Count - 1
Dim dr As DataRow
dr = dt.Rows(i)
Dim D = New DataGridView
D.Visible = True
Dim tp As New TabPage
tp.Name = "tp" & i
tp.Text = dr.Item("Desc2")
frmUI.tcFee.TabPages.Add(tp)
frmUI.tcFee.TabPages(i).Controls.Add(D)
dgv_Fill(D, "SELECT * FROM Fee WHERE ClassID=" & dr.Item("ClassID") & " ORDER BY Seq")
D.AutoResizeColumns()
D.Width = tp.Width
D.Height = tp.Height
Next i
this does not work:
With frmUI.Controls("D" & i)
.AutoResizeColumns()
.Width = tp.Width
.Height = tp.Height
End With
D is purely the variable name in the scope you are using it in.
You need to give the control a unique Name that yo can reference it by later.
The Name property can be used at run time to evaluate the object by
name rather than type and programmatic name. Because the Name property
returns a String type, it can be evaluated in case-style logic
statements (Select statement in Visual Basic, switch statement in
Visual C# and Visual C++).
I found a solution to the problem. The problem is that the new row has an autonumber ID.
When da.update(dt) occurs, the new row is inserted to the database. The database knows the new autonumber ID. However, the datatable does not.
For the datatable to know, the dataadapter is refilled. However, this causes the datatable to have all the old rows plus all the new rows and they all appear in the datagridview.
By clearing the old rows from the datatable, the fill refreshes all the data in the datatable and therefore refreshes the datagridview.
Public Sub dgv_AddRow(ByVal dgvName As String)
Dim dgv As DataGridView = colDataGridView.Item(dgvName)
Dim da As SqlDataAdapter = colDataAdapter.Item(dgvName)
Dim dr As DataRow = frmUI.allDataSet.Tables(dgvName).NewRow
'autopopulate the class id
dr("ClassID") = dgv.Parent.Tag
'add the new row
frmUI.allDataSet.Tables(dgvName).Rows.Add(dr)
'get the changed table
Dim dt As DataTable = frmUI.allDataSet.Tables(dgvName)
'inserts the new row to the database. concurrency violation
'will occur because datatable does not know the new Autonumber ID for the new row.
da.Update(dt)
'remove the datatable rows so they can be replaced using the adapter fill
'if rows are not cleared, following fill causes datatable to
'have existing rows plus all the rows again due to the fill
frmUI.allDataSet.Tables(dgvName).Rows.Clear()
'refill the adapter (refill the table)
'Everything you do to the underlying dataTable
'gets displayed instantly on the datagridview
da.Fill(frmUI.allDataSet, dgvName)
End Sub
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