Windows Forms FAQ resources

5. Windows Forms Datagrid

5.81 How can I use events to restrict key input to grid cells?

If you make sure your DataGrid is using a DataGridTableStyle, then you can access the TextBox through the GridColumnStyles collection and hook the event there. Here is some code....

[C#]

//in formload

this.dataGrid2.DataSource = this.dataSet11.Customers; // set the data source

//make sure grid has a tablestyle

DataGridTableStyle ts = new DataGridTableStyle();

ts.MappingName = this.dataSet11.Customers.TableName;

this.dataGrid2.TableStyles.Add(ts);

//now we can wire up wire up events for columns 1 and 4 ....

DataGridTextBoxColumn tbc = (DataGridTextBoxColumn)ts.GridColumnStyles[0];

tbc.TextBox.KeyPress += new KeyPressEventHandler(CellKeyPress);

tbc = (DataGridTextBoxColumn)ts.GridColumnStyles[3];

tbc.TextBox.KeyPress += new KeyPressEventHandler(CellKeyPress);.....

//the handler

private void CellKeyPress(object sender, KeyPressEventArgs e)

{

//don't allow 1's

if(e.KeyChar == '1')

e.Handled = true;

}

[VB.NET]

'in formload

Me.dataGrid2.DataSource = Me.dataSet11.Customers ' set the data source

'make sure grid has a tablestyle

Dim ts As New DataGridTableStyle()

ts.MappingName = Me.dataSet11.Customers.TableName

Me.dataGrid2.TableStyles.Add(ts)

'now we can wire up wire up events for columns 1 and 4 ....

Dim tbc as DataGridTextBoxColumn = CType(ts.GridColumnStyles(0), DataGridTextBoxColumn)

AddHandler tbc.TextBox.KeyPress, AddressOf CellKeyPress

tbc = CType(ts.GridColumnStyles(3), DataGridTextBoxColumn)

AddHandler tbc.TextBox.KeyPress, AddressOf CellKeyPress

.....

'the handler

Private Sub CellKeyPress(sender As Object, e As KeyPressEventArgs)

'don't allow 1's

If e.KeyChar = "1"c Then

e.Handled = True

End If

End Sub 'CellKeyPress