Prism 6.3迁移至8.1 WPF应用：日志功能适配及集成疑问

Prism 8.1是否自带日志功能？ #

Prism 8.1没有自带日志功能。从Prism 7.x版本开始，官方移除了内置的日志抽象层与默认实现，转为推荐开发者根据项目需求自行集成第三方日志框架。

集成Microsoft.Practices.EnterpriseLibrary.Logging的步骤 #

Prism 8中已废弃PrismBootstrapper类，改用PrismApplication作为WPF应用的启动基类，以下是适配的集成步骤：

• 安装NuGet包
  安装Microsoft.Practices.EnterpriseLibrary.Logging及其依赖的Microsoft.Practices.EnterpriseLibrary.Common包。

• 封装日志服务
  实现一个适配依赖注入的日志包装类，统一日志调用接口：

  public interface ILogger
  {
      void Debug(string message);
      void Error(string message, Exception ex);
      // 可根据需求扩展Info、Warn等其他级别方法
  }
  
  public class EnterpriseLibraryLogger : ILogger
  {
      private readonly LogWriter _logWriter;
  
      public EnterpriseLibraryLogger(LogWriter logWriter)
      {
          _logWriter = logWriter;
      }
  
      public void Debug(string message)
      {
          _logWriter.Write(message, "Debug", (int)Priority.Low);
      }
  
      public void Error(string message, Exception ex)
      {
          var logEntry = new LogEntry
          {
              Message = message,
              Category = "Error",
              Priority = (int)Priority.High,
              ExtendedProperties = { { "ExceptionDetails", ex.ToString() } }
          };
          _logWriter.Write(logEntry);
      }
  }
  

• 在PrismApplication中注册服务
  继承PrismApplication并重写RegisterTypes方法，完成日志服务的初始化与注入注册：

  public partial class App : PrismApplication
  {
      protected override Window CreateShell()
      {
          return Container.Resolve<MainWindow>();
      }
  
      protected override void RegisterTypes(IContainerRegistry containerRegistry)
      {
          // 初始化EnterpriseLibrary LogWriter
          var logWriter = new LogWriterFactory().Create();
          // 注册单例LogWriter与自定义日志服务
          containerRegistry.RegisterInstance(logWriter);
          containerRegistry.Register<ILogger, EnterpriseLibraryLogger>();
      }
  }
  

• 配置日志规则
  在App.config中添加EnterpriseLibrary的日志配置，定义日志输出格式、存储位置等：

  <configuration>
    <configSections>
      <section name="loggingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.LoggingSettings, Microsoft.Practices.EnterpriseLibrary.Logging" />
    </configSections>
    <loggingConfiguration tracingEnabled="true" defaultCategory="General">
      <listeners>
        <!-- 配置滚动文件日志监听者 -->
        <add name="RollingFileListener" 
             type="Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.RollingFlatFileTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging"
             fileName="AppLogs\app.log"
             formatter="TextFormatter"
             rollInterval="Day"
             maxArchivedFiles="15" />
      </listeners>
      <formatters>
        <!-- 定义日志输出格式 -->
        <add name="TextFormatter" 
             type="Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.TextFormatter, Microsoft.Practices.EnterpriseLibrary.Logging"
             template="[{timestamp:yyyy-MM-dd HH:mm:ss}] [{category}] {message}{newline}Exception: {exception}{newline}" />
      </formatters>
      <categorySources>
        <!-- 为不同日志类别绑定监听者 -->
        <add switchValue="All" name="Debug">
          <listeners><add name="RollingFileListener" /></listeners>
        </add>
        <add switchValue="All" name="Error">
          <listeners><add name="RollingFileListener" /></listeners>
        </add>
      </categorySources>
    </loggingConfiguration>
  </configuration>
  

• 在业务代码中使用日志
  通过构造函数注入ILogger，直接调用日志方法：

  public class MainViewModel : BindableBase
  {
      private readonly ILogger _logger;
  
      public MainViewModel(ILogger logger)
      {
          _logger = logger;
          _logger.Debug("MainViewModel 已初始化");
      }
  
      public void ExecuteOperation()
      {
          try
          {
              // 业务逻辑代码
          }
          catch (Exception ex)
          {
              _logger.Error("执行操作时出错", ex);
          }
      }
  }
  

内容的提问来源于stack exchange，提问作者Balaji G