c# - 如果datagridview中的复选框被选中，它将保存到数据库，如果没有，它只会提示选择一行

Question

这是我的代码，但它总是提示您是否要添加行，即使它没有被选中。您认为问题出在哪里？

 private void btn_add_Click(object sender, EventArgs e)
 {
      List<DataGridViewRow> selectedRows = 
        (from row in dg_students.Rows.Cast<DataGridViewRow>() 
              where Convert.ToBoolean(row.Cells[3].Value) == true
              select row).ToList();         

        if (MessageBox.Show(string.Format("Are you sure you want to add this student?", selectedRows.Count), "Confirmation", MessageBoxButtons.YesNo) == DialogResult.Yes)
            {
                foreach (DataGridViewRow row in selectedRows)
                {
                    try
                    {


                        MySqlConnection conn = new MySqlConnection(myconn);
                         string Query = "Insert into southpoint_school.classlist(schoolYear, yearLevel, sectionName, studentID, studentName, gender) values ('" + schoolyr + "','" + cmb_level.Text + "','" + comboBox2.Text + "','" + row.Cells[0].Value.ToString() + "','" + row.Cells[1].Value.ToString() + "','" + row.Cells[2].Value.ToString() + "')";
                        MySqlCommand cmd = new MySqlCommand(Query, conn);
                        conn.Open();
                        cmd.ExecuteNonQuery();
                        conn.Close();
                    }

                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                    MessageBox.Show("Successfully Saved");
                }
            }
}

Answer 1

在当前的 if 语句周围放置一个 if 语句，以检查所选行的数量:

if(selectedRows.Count >= 1)
{
    //Your if statement to run with the selected rows
}
else
{
    //Prompt user to select a row
{