企业库日志记录：尝试获取 LogWriter 类型的实例时发生激活错误，密钥“”

Question

我正在尝试使用 Fluent API 在没有配置文件的情况下编写日志。

这是我的代码：

 var builder = new ConfigurationSourceBuilder();
                builder.ConfigureData()
                .ForDatabaseNamed("Logging")
                .ThatIs.ASqlDatabase()
                .WithConnectionString(ConnectionString)
                .AsDefault();

 var configSource = new DictionaryConfigurationSource();
 builder.UpdateConfigurationWithReplace(configSource);

 var logger = EnterpriseLibraryContainer.Current.GetInstance<LogWriter>();

 logger.Write("Test", "General");

当我运行它时，它只是说

尝试获取 LogWriter 类型的实例时发生激活错误，键“”

我在配置中做错了什么？

Answer 1

缺少两件事：

1. 您忘记使用EnterpriseLibraryContainer.CreateDefaultContainer 方法使用配置更新容器
2. 您正在配置数据访问，但正在尝试使用日志记录块

以下是使用配置信息创建容器的方法：

var builder = new ConfigurationSourceBuilder();
                builder.ConfigureData()
                .ForDatabaseNamed("Logging")
                .ThatIs.ASqlDatabase()
                .WithConnectionString(ConnectionString)
                .AsDefault();

 var configSource = new DictionaryConfigurationSource();
 builder.UpdateConfigurationWithReplace(configSource);

 EnterpriseLibraryContainer.Current 
  = EnterpriseLibraryContainer.CreateDefaultContainer(configSource);

要使用 Fluent API 配置日志记录，请参阅 Using the Fluent Configuration API。

那篇文章的例子是：

var builder = new ConfigurationSourceBuilder();

builder.ConfigureLogging()
       .WithOptions
         .DoNotRevertImpersonation()
       .LogToCategoryNamed("Security")
         .SendTo.FlatFile("Security Log File")
           .FormatWith(new FormatterBuilder()
             .TextFormatterNamed("Text Formatter")
               .UsingTemplate("Timestamp: {timestamp}...{newline})}"))
             .ToFile("security.log")
         .SendTo.EventLog("Formatted EventLog TraceListener")
            .FormatWithSharedFormatter("Text Formatter")
              .ToLog("Application")
       .LogToCategoryNamed("General")
         .WithOptions.SetAsDefaultCategory()
         .SendTo.SharedListenerNamed("Formatted EventLog TraceListener");

var configSource = new DictionaryConfigurationSource();
builder.UpdateConfigurationWithReplace(configSource);
EnterpriseLibraryContainer.Current 
  = EnterpriseLibraryContainer.CreateDefaultContainer(configSource);

如果您希望将日志记录块配置为使用数据访问块写入数据库，您也可以使用流利的界面来完成：

var builder = new ConfigurationSourceBuilder();

builder.ConfigureData()
    .ForDatabaseNamed("Logging")
        .ThatIs.ASqlDatabase()
        .WithConnectionString(@"data source=.\SQLEXPRESS;Integrated Security=SSPI;Database=Logging")
    .AsDefault();

builder.ConfigureLogging()
        .WithOptions
            .DoNotRevertImpersonation()
        .LogToCategoryNamed("General")
            .WithOptions.SetAsDefaultCategory()
            .SendTo.Database("Database Trace Listener")
            .WithAddCategoryStoredProcedure("AddCategory")
            .UseDatabase("Logging")
            .Filter(System.Diagnostics.SourceLevels.All)
            .WithWriteLogStoredProcedure("WriteLog");


var configSource = new DictionaryConfigurationSource();
builder.UpdateConfigurationWithReplace(configSource);
EnterpriseLibraryContainer.Current
    = EnterpriseLibraryContainer.CreateDefaultContainer(configSource);

var logger = EnterpriseLibraryContainer.Current.GetInstance<LogWriter>();
logger.Write(logEntry);
Logger.Write("Test", "General");