c#生成日志并保存到文件中

public static void AppendTextToFile(string fullname, string msg)
{
try
{
 using (StreamWriter sw = File.AppendText(fullname))
 {
    sw.WriteLine(msg);
    sw.Dispose(); } }
    catch (Exception ex)
    {
    throw ex; }
    }
    private void button1_Click(object sender, EventArgs e)
    {
      AppendTextToFile("d:carlog.txt", "aaa");
 }