// Here is the trick for the Background / Foreground Color
// of the Cell - override the Paint method, with our
// own functionality.
protected override void Paint(
System.Drawing.Graphics g,
System.Drawing.Rectangle bounds,
System.Windows.Forms.CurrencyManager source,
int rowNum, // Here is the Row Number
System.Drawing.Brush backBrush,
System.Drawing.Brush foreBrush,
bool alignToRight)
{
// Do we have Subscribers - notify them if we have
if (DataGridDisableCell != null)
{
// Initialize our Event with the current Row and Column Number
DataGridDisableCellEventArgs e = new DataGridDisableCellEventArgs(rowNum, _col);
// Notify Subscribers to call their EventHandlers - where they
// can do whatever they want. After this we check the EnableValue
// Flag, which may be set / unset by a Subscriber.
DataGridDisableCell(this, e);
// Set the Foreground / Back Color according to our Subscribers
if (!e.EnableValue)
{
backBrush = Brushes.Red;
foreBrush = Brushes.White;
}
}
// In any case (enabled or disabled) draw the Column using the Base Method
base.Paint(g, bounds, source, rowNum, backBrush, foreBrush, alignToRight);
}
// Here is the trick to emable / disable the TextBox
// of the Cell - override the Edit method, with our
// own functionality.
protected override void Edit(
System.Windows.Forms.CurrencyManager source,
int rowNum,
System.Drawing.Rectangle bounds,
bool readOnly,
string instantText,
bool cellIsVisible)
{
DataGridDisableCellEventArgs e = null;
// Do we have Subscribers - notify them if we have
if (DataGridDisableCell != null)
{
// Initialize our Event with the current Row and Column Number
e = new DataGridDisableCellEventArgs(rowNum, _col);
// Notify Subscribers to call their EventHandlers - where they
// can do whatever they want. After this we check the EnableValue
// Flag, which may be set / unset by a Subscriber.
DataGridDisableCell(this, e);
}
// Only call the Edit Method (which enables the TextBox in the DataGrid)
// when the Enable Flag has been set by the Subscriber
if (e.EnableValue)
{
base.Edit(source, rowNum, bounds, readOnly, instantText, cellIsVisible);
}
}
// This is our own DataGridDisableCell Handler. Here we can do whatever
// we want. Our Handler must conform to the paramters defined in the delegate.
public void SetEnableValues(object sender, DataGridDisableCellEventArgs e)
{
// OK, our sample uses modulo 5 to disable the Cells. Note, that a Cell
// has NO disable / enable Flag, this is done by the DataGridTextBoxColumn
// Edit Function as follows:
// Enable Cell: Call DataGridTextBoxColumn.Edit
// Disable Cell: Do not call DataGridTextBoxColumn.Edit
if ((e.Column + e.Row) % 2 == 0)
{
e.EnableValue = false; // Do not call DataGridTextBoxColumn.Edit
}
else
{
e.EnableValue = true; // Do not call DataGridTextBoxColumn.Edit
}
}
