C# how to get the selected column ID value from datagridview

Question

I have a DataGridView and users can select columns. I want that selected column to pass the value of the ID attribute. I tried quite a few different ways, but always came back with error. Usual error message - "Index was out of range". Must be non-negative and less than the size of the collection...

few of the lines I tried

int id = Convert.ToInt32(dataGridView1.SelectedRows[0].Cells[0].Value);
int id = Convert.ToInt32(dataGridView1.SelectedCells[0]);
int id = Convert.ToInt32(dataGridView1.Rows[0].Selected);

Solution 1

Int id= Convert.ToInt32(dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[0].Value);

"datagridview1.CurrentRow.Index" gets the index of selected row.

Solution 2

Selected columns haven't information about selected rows, so you can just loop all rows to get your ID.

foreach(DataGridViewRow dgvr in dataGridView1.Rows)
{
    int id = Convert.ToInt32(dgvr.Cells[0].Value);
}

Comments

[Sugafree]

I tried it but I could not get it working. It didnt even come up with the option FirstOrDefult(). However I dont need a default. I only need this ID when the user selects a column and then I need the first cell's value which is the ID of the student

[Fabio]

Simply: int id = (int)dataGridView1.CurrentRow.Cells[0].Value;