I'm trying to make it so that a user can search for whatever they want in a datagridview called dgvDynamic using a textbox called txtSearchDGV and a button called btnSearch. When btnSearch is clicked, only cells containing the text inside txtSearchDGV should appear in the datagridview however, the program crashes and says "System.Windows.Forms.DataGridViewCell.Value.get returned Nothing." What does this mean and what do I need to do to fix it? Thank you.
Private Sub btnSearch_Click(sender As Object, e As EventArgs) Handles btnSearch.Click
Dim temp As Integer = 0
For i As Integer = 0 To dgvDynamic.RowCount - 1
For j As Integer = 0 To dgvDynamic.ColumnCount - 1
If dgvDynamic.Rows(i).Cells(j).Value.ToString = txtSearchDGV.Text Then
MsgBox("Item found")
temp = 1
End If
Next
Next
If temp = 0 Then
MsgBox("Item not found")
End If
End Sub
If the cell has no value here:
If dgvDynamic.Rows(i).Cells(j).Value.ToString = txtSearchDGV.Text Then
then that Value property is Nothing, i.e. no object, and you can't call a method, e.g. ToString, on an object that doesn't exist. One option would be to use CStr instead, which will handle nulls:
If CStr(dgvDynamic.Rows(i).Cells(j).Value) = txtSearchDGV.Text Then
Related
How do i pass my 2nd selected row in datagridview to textboxt. I only know how to put the first data. How do i pass the 2nd selected to textbox?
Dim i As Integer
i = DataGridView2.SelectedRows(0).Index
Me.txtEmployeeID.Text = DataGridView2.Item(0, i).Value
you can use this code it worked for me
Dim test As String = DataGridView1.SelectedRows(0).Cells(2).Value.ToString
You need to only change the .cell(Here write the index value of the cell)
Then you can use the string value to fill up textbox
Try using the following:
Dim secondRow as integer = 0
Private Sub DataGridView2_CellContentClick(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView2.CellClick
'assuming that by second selected row, you mean the row after the selected row
secondRow = e.RowIndex + 1
End Sub
Private Sub RowToTextBox()
Try
For i = 0 to DataGridView2.ColumnCount - 1
txtEmployeeID.Text &= DataGridView2.Item(i, secondRow)
Next
Catch ex as Exception
MsgBox("You have selected the final row")
End Try
End Sub
I don't think Me. is needed when referring to a textbox in the same form.
Since you don't know how many rows your user will select, I think looping thought the SelectedRows collection might work. I used the Name column because that is what I happened to have in my grid. Instead of a MessageBox you could add the values to a ListBox.
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
For Each GridRow As DataGridViewRow In DataGridView1.SelectedRows
MessageBox.Show($"Value is {GridRow.Cells("Name").Value}")
Next
End Sub
I'm trying to show the rownumber of a datagridview in the headercell I was under the impression that this was possible but I can't get it to show the value.
What do I need to do?
** The dgv is bound with BindingSource **
My attempt:
Private Sub NumberRows()
For Each oRow As DataGridViewRow In dgvBodyOverview.Rows
oRow.HeaderCell.Value = (oRow.Index + 1).ToString
Next
End Sub
To reproduce your problem, I followed your comment:
I'm calling it from a sub that loads all rows and at the end the call is made.
Doing this, the numbers failed to show whether or not the grid had a DataSource. Instead, I've typically done this as Plutonix suggested above - in DataGridView.CellFormatting.
Private Sub dataGridView1_CellFormatting(sender As Object, e As DataGridViewCellFormattingEventArgs)
Dim header As DataGridViewRowHeaderCell = Me.dataGridView1.Rows(e.RowIndex).HeaderCell
If e.ColumnIndex = 0 Then
header.Value = [String].Format("{0}", e.RowIndex + 1)
End If
End Sub
I check for ColumnIndex = 0 to ensure the header cell value is only set once per row. See this C# answer for additional explanation.
I want to run a code like this, but it always jumps over the loop, so I see no line in the console.
That means that selectedColumns is empty. My assumption was that I (or the user) select a cell from a Column and then, selectedColummns are +1. But as it looks, it doesnt work. Then I tried to set proberties of selectionMode to select full columns, but then an exception is thrown:
"System.InvalidOperationException" Additional Information: the SortMode cannot be Automatic, if full Column selection is selected.
I don't know what SortMode is.
For Each col As DataGridViewColumn In datagridview2.SelectedColumns
Console.Write(datagridview2.SelectedColumns.Count)
Console.Write("1")
Next
Any Ideas how to get that the columns into selectedColumns?
Here my code that solved my problem, but I guess it is not the smartest one:
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim body As String = ""
Dim myWriter As New StreamWriter("H:\downloads\test.csv", True)
Dim list As List(Of Integer) = New List(Of Integer)
For Each cell As DataGridViewCell In datagridview2.SelectedCells
If list.Contains(cell.ColumnIndex) = False Then
list.Add(cell.ColumnIndex)
End If
Next
For i = 0 To datagridview2.Rows.Count - 1
For ix = 0 To datagridview2.Columns.Count - 1
If list.Contains(ix) Then
If datagridview2.Rows(i).Cells(ix).Value IsNot Nothing Then
body = body + datagridview2.Rows(i).Cells(ix).Value.ToString + ";"
Else
body = body + ";"
End If
End If
Next
myWriter.WriteLine(body)
body = ""
Next
myWriter.Close()
End Sub
You need to do this after the selected changed event has fired.
For example:
Private Sub Mydg_ColSelected(sender As Object, e As SelectionChangedEventArgs) Handles datagridview2.SelectionChanged
For Each col As DataGridViewColumn In datagridview2.SelectedColumns
Console.Write(datagridview2.SelectedColumns.Count)
Console.Write("1")
Next
End Sub
Or if this isn't what you are after, then try handling the ColumnHeaderMouseClick event instead. I'm not sure what technology you are using, e.g Winforms, WPF, silverlight
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
I have a datagridview (unbound). Fields are Name, Family Name and Phone No and a checkbox colum.
There are ten rows in that DataGridView.
There is an OK button
I need to get message of showing which rows user has checked. The message should appear when user clicks on the OK button. There could be several messages, checking each row one by one, in a loop.
I am not able to get this message. I tried following code in OK button :
Dim strCB As String = dgvChooseQs.Rows(0).Cells(3).Value.ToString
Cell(3) is my checkbox. Do not consider Rows(0), at the moment I am just checking value at row 0
Thanks for your help.
Furqan
Do not use the cell index. Your checkbox column must have a name so you should use it.
Otherwise, what you want to do would be something like this
For each oRow as DataGridViewRow in dgvChooseQs.Rows
If oRow.Cells("ColNamE").Value = True then
'do whatever you need to do.
End if
Next
If you feel you need to cast the column, then you can use CType, but the type is DataGridViewCheckBoxCell, not CheckBox.
You need to do something like this:
if ctype(dgvChooseQs.Rows(0).findcontrol("whateverYourCheckBoxIsNamed"), checkbox).checked then
'throw the message
end if
You may cast the cell value to Boolean, and then check it, as follows:
Dim RowIndex As Integer = ...
Dim ColumnIndex As Integer = ...
Dim IsTicked As Boolean = CBool(DataGridView1.Rows(RowIndex).Cells(ColumnIndex).Value)
If IsTicked Then
MessageBox.Show("You ticked the box.")
Else
MessageBox.Show("You cleared the box.")
End If
Only the third example worked for me but I had to add a Timer
Private Sub DgvElencoFile_CellClick(sender As Object, e As DataGridViewCellEventArgs) Handles DgvElencoFile.CellClick
'Variabili gestione programma
Dim numerocolonnaSelezionata As Integer
Dim numeroColonnaSelezionataPerDowonload As Integer
Dim numeroRigaSelezionata As Integer
numeroRigaSelezionata = e.RowIndex
NumerocolonnaSelezionata = e.ColumnIndex
If NumeroRigaSelezionata < 0 Then
ClaFunzSgnSon.SegnaleSonoro(ClaFunzSgnSon.EnTipoSgnSon.ErroreImpostazioneDati)
GoTo FineSubFunz
End If
numeroColonnaSelezionataPerDowonload = -1
If DgvElencoFile.Rows(numeroRigaSelezionata).Cells(ClnDownLoad.Name).Selected Then numeroColonnaSelezionataPerDowonload = numerocolonnaSelezionata
If numeroColonnaSelezionataPerDowonload >= 0 Then
TimVisCheckDownLoad.Start()
End If
FineSubFunz:
End Sub
Private Sub TimVisCheckDownLoad_Tick(sender As Object, e As EventArgs) Handles TimVisCheckDownLoad.Tick
TimVisCheckDownLoad.Stop()
Dim isTickedOn = CBool(DirectCast(DgvElencoFile.CurrentCell, DataGridViewCheckBoxCell).EditingCellFormattedValue)
If isTickedOn Then
MessageBox.Show("You ticked the box.")
Else
MessageBox.Show("You cleared the box.")
End If
End Sub
I found a simple solution.
Just change the cell focus after click on cell.
Private Sub DGV_CellContentClick(sender As Object, e As DataGridViewCellEventArgs) Handles DGV.CellContentClick
If e.ColumnIndex = "Here checkbox column id or name" Then
DGV.Item(e.ColumnIndex, e.RowIndex + 1).Selected = True
'Here your code
MsgBox DGV.Item(e.ColumnIndex, e.RowIndex).Value
End If
End Sub
Don't forget to check if the column of your (ckeckbox + 1) index exist.
Set type of grid in dataGridView to 'DataGridViewCheckBoxXColumn' instead of DataGridViewCheckBoxColumn.
all problems will be solved
The post is old but it can help in need:
You have these three properties after casting your cell:
Private Sub YourDataGridView_CellMouseClick(sender As Object, e As DataGridViewCellMouseEventArgs) Handles YourDataGridView.CellMouseClick
Dim b, b1, b2 As Boolean
b = DirectCast(YourDataGridView.CurrentCell, DataGridViewCheckBoxCell).EditingCellValueChanged
b1 = CBool(DirectCast(YourDataGridView.CurrentCell, DataGridViewCheckBoxCell).EditingCellFormattedValue)
b2 = CBool(DirectCast(YourDataGridView.CurrentCell, DataGridViewCheckBoxCell).EditedFormattedValue)
End Sub
it's a long time since this question was sent, but can be useful this answer to anybody with the same issue. In my case, I used (I'm using your notation):
dgvChooseQs.Item(6, vCont).State
where 6 is the checkbox column number, in my case column 6. vCont is an iteration counter in a FOR NEXT loop. If State equals 32, checkbox was checked, else State will be zero. I hope this can be of help.