Question

I’m working on a windows form project. In my form I have a datagrid with a column that must be filled in every row.

I’d like to obtain something similar to MS Mangement Studio: if the mandatory cell in the current row is not filled i could not add another row.

How can i do that?

Answer 1

Use the CellValidiating event to check the value of the column.

Something like this:

    const int MandatoryColumnIndex = 1;
    public Form1()
    {
        InitializeComponent();
        dataGridView1.CellValidating += new DataGridViewCellValidatingEventHandler(dataGridView1_CellValidating);
        dataGridView1.RowValidating += new DataGridViewCellCancelEventHandler(dataGridView1_RowValidating);

    }

    private void dataGridView1_RowValidating(object sender, DataGridViewCellCancelEventArgs e)
    {

        if (dataGridView1.Rows[e.RowIndex].Cells[MandatoryColumnIndex].FormattedValue.ToString() == string.Empty)
        {
            e.Cancel = true;
            dataGridView1.Rows[e.RowIndex].Cells[MandatoryColumnIndex].ErrorText = "Mandatory";
        }
        else
        {
            dataGridView1.Rows[e.RowIndex].Cells[MandatoryColumnIndex].ErrorText = string.Empty;
        }
    }

    private void dataGridView1_CellValidating(object sender, DataGridViewCellValidatingEventArgs e)
    {
        if (e.ColumnIndex == MandatoryColumnIndex)
        {
            if (e.FormattedValue.ToString() == string.Empty)
            {
                dataGridView1[e.ColumnIndex, e.RowIndex].ErrorText = "Mandatory";
                e.Cancel = true;
            }
            else
            {
                dataGridView1[e.ColumnIndex, e.RowIndex].ErrorText = string.Empty;
            }           
        }
    }