C#构造函数在执行代码后调用构造函数

Question

我已经看到有关构造函数链接的答案，但它们不适用于我的问题。

我有一个需要几个参数的以下构造函数：

public SerilogHelper(string conString, int minLevel)
    {
        var levelSwitch = new LoggingLevelSwitch();
        levelSwitch.MinimumLevel = (Serilog.Events.LogEventLevel)(Convert.ToInt32(minLevel));

        _logger = new LoggerConfiguration()
            .MinimumLevel.ControlledBy(levelSwitch)
            .WriteTo.MSSqlServer(connectionString: conString, 
                                 tableName: "Logs", 
                                 autoCreateSqlTable: true)
            .CreateLogger();
    }

这个构造函数的一个特定客户端没有参数所需的值，所以我希望能够调用这个简单的构造函数，它会获取所需的值，然后调用第一个构造函数：

public SerilogHelper()
    {
        string minLevel = SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
          "LCC.Common", "serilog.level");
        string conString = SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
          "LCC.Common", "serilog.connectionstring");

        SerilogHelper(conString, minLevel);
    }

问题是，我在调用第二个构造函数时得到一个红色波浪形消息 SerilogHelper is a 'type' but used like a 'variable'

Answer 1

为什么不简单地添加这些参数？

// this assumes that SSOSettingsFileManager is static class
// this will automatically call these methods before passing 
// values to another ( non parameterless ) constructor
public SerilogHelper()
    : this ( 
        SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
            "LCC.Common", "serilog.connectionstring"
        ),
        SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
            "LCC.Common", "serilog.level"
        )
    )
{

}

// This will be called from default ( parameterless )
// constructor with values retrieved from methods
// called in previous constructor.
public SerilogHelper(string conString, int minLevel)
{
        var levelSwitch = new LoggingLevelSwitch();
        levelSwitch.MinimumLevel = (Serilog.Events.LogEventLevel)(Convert.ToInt32(minLevel));

        _logger = new LoggerConfiguration()
            .MinimumLevel.ControlledBy(levelSwitch)
            .WriteTo.MSSqlServer(connectionString: conString, 
                                 tableName: "Logs", 
                                 autoCreateSqlTable: true)
            .CreateLogger();
}

Test online

Answer 2

你不能那样做。您拥有它的最佳选择是将初始化代码移动到一个单独的方法中，您可以从两个构造函数中调用该方法。 是允许的。

public SerilogHelper()
{
    string minLevel = SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
      "LCC.Common", "serilog.level");
    string conString = SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
      "LCC.Common", "serilog.connectionstring");

    this.Initialize(conString, minLevel);
}

public SerilogHelper(string conString, int minLevel)
{
    this.Initialize(conString, minLevel);
}

protected void Initialize(string conString, int minLevel)
{
    var levelSwitch = new LoggingLevelSwitch();
    levelSwitch.MinimumLevel = (Serilog.Events.LogEventLevel)(Convert.ToInt32(minLevel));

    _logger = new LoggerConfiguration()
        .MinimumLevel.ControlledBy(levelSwitch)
        .WriteTo.MSSqlServer(connectionString: conString, 
                             tableName: "Logs", 
                             autoCreateSqlTable: true)
        .CreateLogger();
}

Answer 3

我建议使用默认值：

public SerilogHelper(string conString = null, int minLevel = -1)
{
    if (minLevel == -1)
      minLevel = SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
      "LCC.Common", "serilog.level");

    if (conString == null)
      conString = SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
      "LCC.Common", "serilog.connectionstring");

    var levelSwitch = new LoggingLevelSwitch();
    levelSwitch.MinimumLevel = (Serilog.Events.LogEventLevel)(Convert.ToInt32(minLevel));

    _logger = new LoggerConfiguration()
        .MinimumLevel.ControlledBy(levelSwitch)
        .WriteTo.MSSqlServer(connectionString: conString, 
                             tableName: "Logs", 
                             autoCreateSqlTable: true)
        .CreateLogger();
}

....

SerilogHelper myInstance = new SerilogHelper();

编辑：我假设 minLevel = -1 是 invalid 可以用作默认值，如果不是这种情况（任何 minLevel 值是允许的）int? 是一个可能的出路：

public SerilogHelper(string conString = null, int? minLevel = null)
{
    if (!minLevel.HasValue)
      minLevel = SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
      "LCC.Common", "serilog.level");

    if (conString == null)
      conString = SSOSettingsFileManager.SSOSettingsFileReader.ReadString(
      "LCC.Common", "serilog.connectionstring");

    var levelSwitch = new LoggingLevelSwitch();
    levelSwitch.MinimumLevel = (Serilog.Events.LogEventLevel)(Convert.ToInt32(minLevel));

    _logger = new LoggerConfiguration()
        .MinimumLevel.ControlledBy(levelSwitch)
        .WriteTo.MSSqlServer(connectionString: conString, 
                             tableName: "Logs", 
                             autoCreateSqlTable: true)
        .CreateLogger();
}