Я получаю, как использовать dynamic в С# 4.0, однако я не уверен, как взять что-то и сделать его динамическим (мой технический термин).
Например, вместо ConfigurationManager.AppSettings["blah"], как я могу создать оболочку сорта, которая позволит мне просто использовать ее как динамическую: settings.Blah?
Вам все равно нужна точка входа. Однако оттуда возможности довольно гибкие. Это пример, демонстрирующий, насколько мощная динамическая отправка может быть:
public abstract class MyBaseClass
{
public dynamic Settings
{
get { return _settings; }
}
private SettingsProxy _settings = new SettingsProxy();
private class SettingsProxy : DynamicObject
{
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
var setting = ConfigurationManager.AppSettings[binder.Name];
if(setting != null)
{
result = setting.ToString();
return true;
}
result = null;
return false;
}
}
}
Новая версия с дженериками!
public static class WebConfiguration<T>
{
public static dynamic Get {
get { return _settings; }
}
static readonly SettingsProxy _settings = new SettingsProxy ();
class SettingsProxy : DynamicObject
{
public override bool TryGetMember (GetMemberBinder binder, out object result)
{
var setting = ConfigurationManager.AppSettings [binder.Name];
if (setting != null) {
result = Convert.ChangeType (setting, typeof(T));
return true;
}
result = null;
return false;
}
}
}
Использование
WebConfiguration<int>.Get.UserNameLength
Здесь, позвольте мне показать вам больше возможностей динамической отправки:
/// <summary>
/// Dynamic wrapper for <see cref="AppSettingsSection"/>.
/// </summary>
public class DynamicAppSettings : DynamicObject
{
private string _exeConfigPath;
private System.Configuration.Configuration _config;
/// <summary>
/// Initializes a new instance of the <see cref="DynamicAppSettings"/> class with configuration file
/// of the current application domain.
/// </summary>
public DynamicAppSettings()
: this(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="DynamicAppSettings"/> class with the specified configuration file.
/// </summary>
/// <param name="exeConfigPath">Path to configuration file.</param>
public DynamicAppSettings(string exeConfigPath)
{
if (string.IsNullOrEmpty(exeConfigPath))
throw new ArgumentNullException("exeConfigPath");
_exeConfigPath = exeConfigPath;
_config = ConfigurationManager.OpenMappedExeConfiguration(
new ExeConfigurationFileMap() { ExeConfigFilename = _exeConfigPath },
ConfigurationUserLevel.None);
}
/// <summary>
/// Gets the application settings entry from the configuration file.
/// </summary>
/// <param name="binder"></param>
/// <param name="result"></param>
/// <returns></returns>
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
result = _config.AppSettings.Settings[binder.Name];
return true;
}
/// <summary>
/// Adds or updates application settings entry.
/// </summary>
/// <param name="binder"></param>
/// <param name="value"></param>
/// <returns></returns>
public override bool TrySetMember(SetMemberBinder binder, object value)
{
if (value != null && !(value is string))
{
return base.TrySetMember(binder, value);
}
if (_config.AppSettings.Settings[binder.Name] != null)
{
_config.AppSettings.Settings[binder.Name].Value = value.ToString();
}
else
{
_config.AppSettings.Settings.Add(binder.Name, value.ToString());
}
return true;
}
/// <summary>
/// Invokes <see cref="Configuration.Save"/> method to save changes or removes an entry.
/// </summary>
/// <param name="binder"></param>
/// <param name="args"></param>
/// <param name="result"></param>
/// <returns></returns>
public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
{
if (binder.Name.Equals("Save", StringComparison.OrdinalIgnoreCase))
{
_config.Save();
result = null;
return true;
}
if (binder.Name.Equals("Remove", StringComparison.OrdinalIgnoreCase) &&
args != null && args.Length == 1 && (args[0] is string))
{
_config.AppSettings.Settings.Remove(args[0].ToString());
result = null;
return true;
}
return base.TryInvokeMember(binder, args, out result);
}
}
/// <summary>
/// Dynamic wrapper for <see cref="ConnectionStringsSection"/>.
/// </summary>
public class DynamicConnectionStrings : DynamicObject
{
private string _exeConfigPath;
private System.Configuration.Configuration _config;
/// <summary>
/// Initializes a new instance of the <see cref="DynamicConnectionStrings"/> class with the configuration file
/// of the current application domain.
/// </summary>
public DynamicConnectionStrings()
: this(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="DynamicConnectionStrings"/> class with the specified
/// configuration file.
/// </summary>
/// <param name="exeConfigPath">Path to the configuration file.</param>
public DynamicConnectionStrings(string exeConfigPath)
{
if (string.IsNullOrEmpty(exeConfigPath))
throw new ArgumentNullException("exeConfigPath");
_exeConfigPath = exeConfigPath;
_config = ConfigurationManager.OpenMappedExeConfiguration(
new ExeConfigurationFileMap() { ExeConfigFilename = _exeConfigPath },
ConfigurationUserLevel.None);
}
/// <summary>
/// Gets the connection string value from the configuration file.
/// </summary>
/// <param name="binder"></param>
/// <param name="result"></param>
/// <returns></returns>
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
result = _config.ConnectionStrings.ConnectionStrings[binder.Name].ConnectionString;
return true;
}
/// <summary>
/// Adds or updates a connection string entry in the configuration file.
/// </summary>
/// <param name="binder"></param>
/// <param name="value"></param>
/// <returns></returns>
public override bool TrySetMember(SetMemberBinder binder, object value)
{
if (value != null && !(value is string))
{
return base.TrySetMember(binder, value);
}
if (_config.ConnectionStrings.ConnectionStrings[binder.Name] != null)
{
_config.ConnectionStrings.ConnectionStrings[binder.Name].ConnectionString = value.ToString();
}
else
{
_config.ConnectionStrings.ConnectionStrings.Add(
new ConnectionStringSettings(binder.Name, value.ToString()));
}
return true;
}
/// <summary>
/// Invokes <see cref="Configuration.Save"/> to save changes or removes an entry.
/// </summary>
/// <param name="binder"></param>
/// <param name="args"></param>
/// <param name="result"></param>
/// <returns></returns>
public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
{
if (binder.Name.Equals("Save", StringComparison.OrdinalIgnoreCase))
{
_config.Save();
result = null;
return true;
}
if (binder.Name.Equals("Remove", StringComparison.OrdinalIgnoreCase) &&
args != null && args.Length == 1 && (args[0] is string))
{
_config.ConnectionStrings.ConnectionStrings.Remove(args[0].ToString());
result = null;
return true;
}
return base.TryInvokeMember(binder, args, out result);
}
}
Например:
dynamic apps = new DynamicAppSettings();
apps.UploadLocation = "~/Uploads/";
apps.WebServiceUrl = "http://www.site.com/service.svc";
apps.Remove("TempFolderPath");
apps.Save();
dynamic conns = new DynamicConnectionStrings();
conns.MasterDatabase = "Data Source=lpc:(local);Integrated Security=True;Initial Catalog=master";
conns.Save();