private void button1_Click(object sender, EventArgs e) { if (dataGridView1.SelectedRows.Count > 0) { string sName = dataGridView1.SelectedRows[0].Cells["Sname"].Value.ToString(); stri...-QT开发中文网

在button1_Click方法的末尾，你可以添加以下代码来关闭数据库连接：

finally
{
    connection.Close();
}

完整代码如下所示：

private void button1_Click(object sender, EventArgs e)
{
    if (dataGridView1.SelectedRows.Count > 0)
    {
        string sName = dataGridView1.SelectedRows[0].Cells["Sname"].Value.ToString();
        string cName = dataGridView1.SelectedRows[0].Cells["Cname"].Value.ToString();
        string tName = dataGridView1.SelectedRows[0].Cells["Tname"].Value.ToString();
        string attendanceResult;
        if (radioButton1.Checked)
            attendanceResult = "是";
        else if (radioButton2.Checked)
            attendanceResult = "否";
        else
            return;

        try
        {                    
            connection.Open();

            // 执行插入语句，将考勤信息保存到Attend表中对应的列中
            string query = "INSERT INTO Attend (Sname, Cname, Tname, kaoqin) VALUES (@sName, @cName, @tName, @attendanceResult)";
            SqlCommand command = new SqlCommand(query, connection);
            command.Parameters.AddWithValue("@sName", sName);
            command.Parameters.AddWithValue("@cName", cName);
            command.Parameters.AddWithValue("@tName", tName);
            command.Parameters.AddWithValue("@attendanceResult", attendanceResult);

            command.ExecuteNonQuery();

            MessageBox.Show("考勤保存成功！");
        }
                
        catch (Exception ex)
        {
             MessageBox.Show("保存考勤时出错：" + ex.Message);
        }
                
         finally
         {
             connection.Close();
         }
    }
    else
    {
         MessageBox.Show("请先选择一行数据！");
    }
}

这样，无论在try块中是否发生异常，都会执行finally块的代码来确保数据库连接被关闭。

内容由零声教学AI助手提供，问题来源于学员提问