动软里面 public class PubConstant
  {   
  /// <summary>
  /// 获取连接字符串
  /// </summary>
  public static string ConnectionString
  {   
  get  
  {
  string _connectionString = ConfigurationManager.AppSettings["ConnectionString"];   
  string ConStringEncrypt = ConfigurationManager.AppSettings["ConStringEncrypt"];
  if (ConStringEncrypt == "true")
  {
  _connectionString = DESEncrypt.Decrypt(_connectionString);
  }
  return _connectionString;  
  }
  }

  /// <summary>
  /// 得到web.config里配置项的数据库连接字符串。
  /// </summary>
  /// <param name="configName"></param>
  /// <returns></returns>
  public static string GetConnectionString(string configName)
  {
  string connectionString = ConfigurationManager.AppSettings[configName];
  string ConStringEncrypt = ConfigurationManager.AppSettings["ConStringEncrypt"];
  if (ConStringEncrypt == "true")
  {
  connectionString = DESEncrypt.Decrypt(connectionString);
  }
  return connectionString;
  }


  }
然后我用
 PubConstant.GetConnectionString("workstation id=localhost;Integrated Security=SSPI;database=zbroad2009");
  MessageBox.Show(PubConstant.ConnectionString);
结果发现.ConnectionString 是NULL
是空的
这个Connectionstring 如何赋值呢

PubConstant.GetConnectionString("ConnectionString");