方法一（不使用SQLDMO）：

///
///备份方法
///
SqlConnection conn = new SqlConnection("Server=.;Database=master;User ID=sa;Password=sa;");

SqlCommand cmdBK = new SqlCommand();
cmdBK.CommandType = CommandType.Text;
cmdBK.Connection = conn;
cmdBK.CommandText = @"backup database test to disk='C:\ba' with init";

try
{
conn.Open();
cmdBK.ExecuteNonQuery();
MessageBox.Show("Backup successed.");
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
conn.Close();
conn.Dispose();
}

///
///还原方法
///
SqlConnection conn = new SqlConnection("Server=.;Database=master;User ID=sa;Password=sa;Trusted_Connection=False");
conn.Open();

//KILL DataBase Process
SqlCommand cmd = new SqlCommand("SELECT
spid FROM sysprocesses ,sysdatabases WHERE
sysprocesses.dbid=sysdatabases.dbid AND sysdatabases.Name='test'",
conn);
SqlDataReader dr;
dr = cmd.ExecuteReader();
ArrayList list = new ArrayList();
while(dr.Read())
{
list.Add(dr.GetInt16(0));
}
dr.Close();
for(int i = 0; i < list.Count; i++)
{
cmd = new SqlCommand(string.Format("KILL {0}", list[i]), conn);
cmd.ExecuteNonQuery();
}

SqlCommand cmdRT = new SqlCommand();
cmdRT.CommandType = CommandType.Text;
cmdRT.Connection = conn;
cmdRT.CommandText = @"restore database test from disk='C:\ba'";

try
{
cmdRT.ExecuteNonQuery();
MessageBox.Show("Restore successed.");
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
conn.Close();
}