Check/Uncheck a checkbox on datagridview

Question

Can someone help me why it doesn't work? I have a checkbox and if I click on it, this should uncheck all the checkbox inside the datagridview which were checked before including the user selected checkbox.

Here is the code:

        private void chkItems_CheckedChanged(object sender, EventArgs e)
        {
            foreach (DataGridViewRow row in datagridview1.Rows)
            {
                DataGridViewCheckBoxCell chk = (DataGridViewCheckBoxCell)row.Cells[1];
                if (chk.Selected == true)
                {
                    chk.Selected = false;
                }
                else
                {
                    chk.Selected = true;
                }
            }
        }

the checkbox should not be selected. it should be checked.

here is the added column

            DataGridViewCheckBoxColumn CheckboxColumn = new DataGridViewCheckBoxColumn();
            CheckBox chk = new CheckBox();
            CheckboxColumn.Width = 20;
            datagridview1.Columns.Add(CheckboxColumn);

Answer 1

You can use this code on your grid CellClick event for check or unchecked cell checkbox :

private void Grid_CellClick(object sender, DataGridViewCellEventArgs e)
    {
        if (e.ColumnIndex == 0)
        {
            Grid.Rows[e.RowIndex].Cells[e.ColumnIndex].Value = (Grid.Rows[e.RowIndex].Cells[e.ColumnIndex].Value == null ? true : (!(bool)Grid.Rows[e.RowIndex].Cells[e.ColumnIndex].Value));
        }
    }

Answer 2

Try the below code it should work

private void checkBox2_CheckedChanged(object sender, EventArgs e) 
{
    if (checkBox2.Checked == false)
    {
        foreach (DataGridViewRow row in dGV1.Rows)
        {
            DataGridViewCheckBoxCell chk = (DataGridViewCheckBoxCell)row.Cells[0];
            chk.Value = chk.TrueValue;
        }
    }
   else if (checkBox2.Checked == true)
    {
        foreach (DataGridViewRow row in dGV1.Rows)
        {
            DataGridViewCheckBoxCell chk = (DataGridViewCheckBoxCell)row.Cells[0];
            chk.Value = 1;
            if (row.IsNewRow)
            {
                chk.Value = 0;
            }
        }
    }
}

Answer 3

you can try this code:

DataGridViewCheckBoxCell chk = (DataGridViewCheckBoxCell)dataGridView1.CurrentRow.Cells[0];
                dataGridView1.BeginEdit(true);
                if (chk.Value == null || (int)chk.Value == 0)
                {
                    chk.Value = 1;
                }
                else
                {
                    chk.Value = 0;
                }
                dataGridView1.EndEdit();

Answer 4

Simple code for you it will work

private void dgv_CellClick(object sender, DataGridViewCellEventArgs e)
{
    if (dgv.CurrentRow.Cells["ColumnNumber"].Value != null && (bool)dgv.CurrentRow.Cells["ColumnNumber"].Value)
    {
        dgv.CurrentRow.Cells["ColumnNumber"].Value = false;
        dgv.CurrentRow.Cells["ColumnNumber"].Value = null;
    }
    else if (dgv.CurrentRow.Cells["ColumnNumber"].Value == null )
    {
        dgv.CurrentRow.Cells["ColumnNumber"].Value = true;
    }
}

Answer 5

The code bellow allows the user to un-/check the checkboxes in the DataGridView, if the Cells are created in code

private void gvData_CellClick(object sender, DataGridViewCellEventArgs e)
{
    DataGridViewCheckBoxCell chk = (DataGridViewCheckBoxCell)gvData.Rows[e.RowIndex].Cells[0];

    if (chk.Value == chk.TrueValue)
    {
        gvData.Rows[e.RowIndex].Cells[0].Value = chk.FalseValue;
    }
    else
    {
        gvData.Rows[e.RowIndex].Cells[0].Value = chk.TrueValue;
    }

}

Answer 6

// here is a simple way to do so

//irate through the gridview
            foreach (DataGridViewRow row in PifGrid.Rows)
            {
//store the cell (which is checkbox cell) in an object
                DataGridViewCheckBoxCell oCell = row.Cells["Check"] as DataGridViewCheckBoxCell;

//check if the checkbox is checked or not
                bool bChecked = (null != oCell && null != oCell.Value && true == (bool)oCell.Value);

//if its checked then uncheck it other wise check it
                if (!bChecked)
                {
                    row.Cells["Check"].Value = true;

                }
                else
                {
                    row.Cells["Check"].Value = false;

                }
            }