I am using Friend WithEvents PersonName As DataGridViewComboBoxColumn as a column in DataGridView and PersonName DataSoucre is bounded to a database. I would like for when the ComboBox Selection is changed it uses that value to query my database Business Object to find the right value then I want to set the value from the query to the column to the right of the one with the ComboBox which is named Colum3.
But am not use how to access each individual event handler for the ComboBox cell, I tried dgvTable.CellBeginEdit but it triggers too early.
Private Sub dgvTable_CellBeginEdit(sender As Object, e As DataGridViewCellCancelEventArgs) Handles dgvTable.CellBeginEdit
If e.RowIndex <> -1 And e.ColumnIndex <> -1 Then
dgvTable.Rows(e.RowIndex).Cells("Colum3").Value = dgvTable.Rows(e.RowIndex).Cells(e.ColumnIndex).Value & "Somevalue from my databse"
End If
End Sub
Related
I am using VS 2005 edition. I am developing a winform desktop application. Let's say I have a unbound datagridview, with table like below:
Original datagrid before delete:
If I removed Stuff D (Item No 5), the "Item No" column supposed to reset itself accordingly. The expected output should be:
After delete row:
The "Item No" column is not an autonumber, it's just the number I assigned incrementally as the user add in a new row(new Stuff). I tried using the following code in rowremoved event but failed to achieve the expected output. Please help. Thanks.
If the goal is just showing the record index in cell, then you don't need to assign a value to cell and it's enough to set e.Value = e.RowIndex + 1 in CellFormatting event.
But based on your comment it seems you need those cells have values as well. So you need to handle RowsRemoved and RowsAdded event of DataGridView and refresh the cell value with row number:
Public Sub RefreshRowNumbers(g As DataGridView)
For Each r As DataGridViewRow In g.Rows
r.Cells(1).Value = r.Index + 1
Next
End Sub
Private Sub DataGridView1_RowsRemoved(sender As Object, _
e As DataGridViewRowsRemovedEventArgs) Handles DataGridView1.RowsRemoved
RefreshRowNumbers(DirectCast(sender, DataGridView))
End Sub
Private Sub DataGridView1_RowsAdded(sender As Object, _
e As DataGridViewRowsAddedEventArgs) Handles DataGridView1.RowsAdded
RefreshRowNumbers(DirectCast(sender, DataGridView))
End Sub
I have a combo box that has a couple items in them, where they add text to a text box. I want to prevent the same item being selected twice in a row, because the index never changed, but it still runs the code.
Here's what I've done:
Dim intComboIndex As Integer = -1
Dim cboComboBox As ComboBox = CType(sender, ComboBox)
Dim intComboSelIndex As Integer = cboComboBox.SelectedIndex
If intComboSelIndex > -1 And intComboSelIndex <> intComboIndex Then intComboIndex = intComboSelIndex
Is there a more efficient way of doing this, without having to create a different combo box and compare the indexes?
You must store the previously selected index elsewhere, because at the moment you recreate the variable every time the event is raised.
I'd recommend storing the previously selected index at class level, and then compare that to the currently selected index.
Public Class Form1
Dim ComboBoxPrevIndex As Integer = -1 'Declared at class level, outside any Sub or Function.
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
Dim SenderBox As ComboBox = DirectCast(sender, ComboBox) 'Get the control that raised the ever.
'Has the selection changed?
If ComboBoxPrevIndex <> SenderBox.SelectedIndex _
AndAlso SenderBox.SelectedIndex > -1 Then
'Do stuff...
End If
ComboBoxPrevIndex = SenderBox.SelectedIndex 'Set the new, previous index.
End Sub
End Class
You might have noticed that I used AndAlso instead of And. This is because of AndAlso is short-circuited, meaning that it will only check the condition on it's right if the condition on it's left evaluates to True.
how to remove data from datagridview..
im using this syntax on button to add data to datagridview..
DataGridView1.Rows.Add(num, TextBox1.Text, id_jenis, harga)
But.. how is the remove syntax to remove selected row on datagridview ?
Use .Remove or .RemoveAt
MyDataGridView.Rows.RemoveAt(index)
then, if you would like to remove selected row, you can previously store the row index using datagridview events like,
Private index as Integer = 0
Private Sub MyDataGridView_CellClick(sender As Object, e As DataGridViewCellEventArgs) Handles MyDataGridView.CellClick
index = e.RowIndex
End Sub
I have a datagridview with two textbox columns and one combobox column. The combobox's DataSource is bound to enums for the values of the dropdown. The datagridview's DataSource is bound to a custom class with datatypes of string, string and enum.
The first two columns are pre-populated with values and in the third column the user must select a value from the dropdown. All this is working excellent so far except....
The combobox field should be a one-to-one kind of mapping, meaning no two comboboxes should have the same value. I am really not sure how to implement this kind of behavior. Should the chosen value be removed from the remaining dropdowns? should the chosen value remain in the dropdown and just give an error when two of the same are selected?
Any ideas and how to implement these ideas will be of great help.
Thanks
note the only acceptable value that can be used more than once is 'None'
I have an idea based off your intent to possibly remove the chosen value from the remaining dropdowns.
I have a class called Runner which has a similar setup to your example.
Public Class Runner
Public Property FirstName As String
Public Property LastName As String
Public Property Placement As Result
Public Sub New(fn As String, ln As String)
FirstName = fn
LastName = ln
Placement = Result.None
End Sub
End Class
I also have an enum called Result which will get populated into the ComboBoxCell:
Public Enum Result
None = 0
Bronze = 1
Silver = 2
Gold = 3
End Enum
When I create data objects and bind them to the DataGridView, I do so like this (note - Placements is a global List(Of Result) and Runners is a global List(Of Runner):
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Placements.Add(Result.None)
Placements.Add(Result.Bronze)
Placements.Add(Result.Silver)
Placements.Add(Result.Gold)
Runners.Add(New Runner("John", "Smith"))
Runners.Add(New Runner("Jane", "Doe"))
Runners.Add(New Runner("Bill", "Jones"))
Column1.DataPropertyName = "FirstName"
Column2.DataPropertyName = "LastName"
Column3.DataPropertyName = "Placement"
Column3.DataSource = Placements
DataGridView1.DataSource = Runners
End Sub
Now, whenever the value of a cell in the ComboBoxColumn changes, you remove the new value from the list that contains the enums:
Private Sub DataGridView1_CellValueChanged(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellValueChanged
If (e.RowIndex > -1 And e.ColumnIndex = 2) Then
Dim currentvalue As Result = DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value
If currentvalue <> Result.None Then
Placements.Remove(currentvalue)
End If
End If
End Sub
Be careful when changing drop down selections... as per this Discussion, you have to trick the DataGridView into committing values as soon as the ComboBox value changes. I used an answer from that discussion and did something like this:
Private Sub DataGridView1_CurrentCellDirtyStateChanged(sender As Object, e As EventArgs) Handles DataGridView1.CurrentCellDirtyStateChanged
Dim col As DataGridViewColumn = DataGridView1.Columns(DataGridView1.CurrentCell.ColumnIndex)
If col.Name = "Column3" Then
DataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit)
Dim selected As DataGridViewCell = DataGridView1.CurrentCell
DataGridView1.CurrentCell = Nothing //This line and the next one simply hide
DataGridView1.CurrentCell = selected //an odd display effect that occurs
//because we remove a value and change the
//selection at the same time
End If
End Sub
Finally, you want to handle the DataError event for the DataGridView and leave it blank so that you don't get Exceptions thrown at you when removing values from your list of enums.
This gets you about 90% of the way there. It will not re-add items to the list when you change a value. For example if I change from Gold to Silver, Gold should be added back to the list. You can probably figure out what events to handle to get the old value and the new one, and insert the old value back into the list at the correct index based on its enum value.
I decided to use the CellValidating event of the DataGridView to check whether or not the same value is selected more than once. If it is then a error message is displayed in the row header column.
The combobox in error will not lose focus until the error is resolved.
Private Sub DataGridView1_CellValidating(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellValidatingEventArgs) Handles DataGridView1.CellValidating
Dim headerText As String = DataGridView1.Columns(e.ColumnIndex).HeaderText
'Abort validation if cell is not in the Mapping column.
If Not headerText.Equals("Column Mapping") Then Return
'Clear error on current row.
DataGridView1.Rows(e.RowIndex).ErrorText = Nothing
e.Cancel = False
Dim newMappingValue As XmlElement = DirectCast([Enum].Parse(GetType(XmlElement), e.FormattedValue), XmlElement)
' Abort validation if cell value equal XmlElement.None
If newMappingValue.Equals(XmlElement.None) Then Return
For Each dgvRow As DataGridViewRow In DataGridView1.Rows
Dim currentMappingValue As XmlElement = dgvRow.Cells.Item(headerText).Value
If dgvRow.Index <> e.RowIndex Then
If currentMappingValue.Equals(newMappingValue) Then
DataGridView1.Rows(e.RowIndex).ErrorText = "Value already selected, please select a different value."
e.Cancel = True
End If
End If
Next
End Sub
How can I select a single cell from selected row in datagridView and after selecting that I want to put simple search functionality (like we have in our windows folders-typing any characters and search should work)?
I do not really understand your question. If you want to select one cell, you can use the celldoubleclick event for exemple. And the to get the selected cell, use e.rowindex and e.columnindex which will give you the row and the column where the cell is located.
You can try this as a possible solution.
Dim nwData as CustomersDataSet = CustomersDataSet.GetCustomers()
m_CustomersGrid.DataSource = m_CustomersBindingSource
m_CustomersBindingSource.DataSource = nwData.Customers
Then you can sort using the BindingSource.
CustomersBindingSource.Sort = "ContactName ASC"
And you can find using the BindingSource.
Dim index as integer = _
CustomersBindingSource.Find("CompanyName", CompanyNameTextBox.Text)
If index <-1 then 'it was found; move to that position
CustomersBindingSource.Position = index
End If
You could then populate:
CustomersBindingSource.Find("CompanyName", CompanyNameTextBox.Text)
with the keys pressed in the cell by capturing them by utilizing:
Private Sub DataGridView1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles DataGridView1.KeyUp
Dim dgv As DataGridView = TryCast(sender, DataGridView)
If dgv IsNot Nothing Then
'You will need some logic here to determine how long to wait between keyups
'Perhaps a timer that ticks every500 milliseconds and reset on keyup.
e.KeyData
End If
End Sub
I found the original Biding Source Logic at : This Location