Triggering a checkbox value changed event in DataG

Question

I have a grid view that has a check box column, and I want to trigger a drawing event as soon as the value of the cell is toggled. I tried the ValueChaged and the CellEndEdit and BeginEdit, and chose the selection mode as CellSelect. As for the the first 2 events, the event was triggered upon the finishing of the edit mode, like moving out of the current cell, or going back and forth. It's just a weird behavior.

Is there anything that triggers the event on the grid view as soon as the cell value is changed?

Answer 1

Using the .EditedFormattedValue property solves the problem

To be notified each time a checkbox in a cell toggles a value when clicked, you can use the CellContentClick event and access the preliminary cell value .EditedFormattedValue.

As the event is fired the .EditedFormattedValue is not yet applied visually to the checkbox and not yet committed to the .Value property.

private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
   var checkbox = dataGridView1.CurrentCell as DataGridViewCheckBoxCell;

   bool isChecked = (bool)checkbox.EditedFormattedValue;

}

The event fires on each Click and the .EditedFormattedValue toggles

Answer 2

Try hooking into the CellContentClick event. The DataGridViewCellEventArgs will have a ColumnIndex and a RowIndex so you can know if a ChecboxCell was in fact clicked. The good thing about this event is that it will only fire if the actual checkbox itself was clicked. If you click on the white area of the cell around the checkbox, it won't fire. This way, you're pretty much guaranteed that the checkbox value was changed when this event fires. You can then call Invalidate() to trigger your drawing event, as well as a call to EndEdit() to trigger the end of the row's editing if you need that.

Answer 3

Every one of the CellClick and CellMouseClick answers is wrong, because you can change the value of the cell with the keyboard and the event will not fire. Additionally, CurrentCellDirtyStateChanged only fires once, which means if you check/uncheck the same box multiple times, you will only get one event. Combining a few of the answers above gives the following simple solution:

private void dgvList_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
    if (dgvList.CurrentCell is DataGridViewCheckBoxCell)
        dgvList.CommitEdit(DataGridViewDataErrorContexts.Commit);
}

private void dgvList_CellValueChanged(object sender, DataGridViewCellEventArgs e)
{
    // Now this will fire immediately when a check box cell is changed,
    // regardless of whether the user uses the mouse, keyboard, or touchscreen.
    //
    // Value property is up to date, you DO NOT need EditedFormattedValue here.
}

Answer 4

Use this code, when you want to use the checkedChanged event in DataGrid View:

private void grdBill_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
    grdBill.CurrentCell =  grdBill.Rows[grdBill.CurrentRow.Index].Cells["gBillNumber"];
}

private void grdBill_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
    calcBill();
}

private void calcBill()
{
    listBox1.Items.Clear();
    for (int i = 0; i < grdBill.Rows.Count - 1; i++)
    {
        if (Convert.ToBoolean(grdBill.Rows[i].Cells["gCheck"].Value) == true)
        {
            listBox1.Items.Add(grdBill.Rows[i].Cells["gBillNumber"].Value.ToString());
        }
    }
}

Here, grdBill = DataGridView1, gCheck = CheckBox in GridView(First Column), gBillNumber = TextBox in Grid (Second column).

So, when we want to fire checkchanged event for each click, first do the CellContentClick it will get fire when user clicked the Text box, then it will move the current cell to next column, so the CellEndEdit column will get fire, it will check the whether the checkbox is checked and add the "gBillNumber" in list box (in function calcBill).

Answer 5

Another way is to handle the CellContentClick event (which doesn't give you the current value in the cell's Value property), call grid.CommitEdit(DataGridViewDataErrorContexts.Commit) to update the value which in turn will fire CellValueChanged where you can then get the actual (i.e. correct) DataGridViewCheckBoxColumn value.

private void grid_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
   grid.CommitEdit(DataGridViewDataErrorContexts.Commit);
}

private void grid_CellValueChanged(object sender, DataGridViewCellEventArgs e)
{
    // do something with grid.Rows[e.RowIndex].Cells[e.ColumnIndex].Value
}

Target .NET framework: 2.0

Answer 6

A colleague of mine recommends trapping the CurrentCellDirtyStateChanged event. See http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.currentcelldirtystatechanged.aspx.