如何取消订阅 NLog 目标

Question

我想要一个 NLog 目标停止监听日志。 RemoveTarget方法似乎不起作用。 这是一个失败的测试。

public class when_stopping_to_listen
{
    static Logger Logger;
    static MemoryTarget target;

    Establish context = () =>
    {
        var config = new LoggingConfiguration();
        Logger = LogManager.GetLogger("TestLogger");

        target = new MemoryTarget {Layout = "${message}", Name = "TestTarget"};

        config.AddTarget(target.Name, target);
        config.LoggingRules.Add(new LoggingRule("*", LogLevel.Trace, target));

        LogManager.Configuration = config;
    };

    Because of = () =>
    {
        var config = LogManager.Configuration;
        config.RemoveTarget(target.Name);
        LogManager.Configuration = config;
        Logger.Info("Test");
    };

    It should_be_empty = () => target.Logs.ShouldBeEmpty();
}

提前致谢。

Answer 1

我不知道为什么RemoveTarget不起作用。 但是，如果您从每个规则中删除目标，则测试通过：

Because of = () =>
{
    foreach (var rule in config.LoggingRules)
    {
        rule.Targets.Remove(target);
    }        
    Logger.Info("Test");
};

如果您删除LoggingRule而不是目标，它也可以工作：

public class when_stopping_to_listen
{
    //...
    static LoggingRule rule;

    Establish context = () =>
    {
        //...
        rule = new LoggingRule("*", LogLevel.Trace, target);
        config.LoggingRules.Add(rule);    
        LogManager.Configuration = config;
    };

    Because of = () =>
    {
        var config = LogManager.Configuration;
        config.LoggingRules.Remove(rule);
        LogManager.Configuration = config;
        Logger.Info("Test");
    };      

    //...
}

Answer 2

NLog 版本。 4.5 修复了LoggingConfiguration.RemoveTarget以便从所有注册的 LoggingRules 中删除目标。

另见： https : //github.com/NLog/NLog/pull/2549