Making NLog config file user define at run time

Question

I have a winForm app. I am using NLog for logging purpose. My config file is below. Can I make any paramter in this config file user define at run time. e.g for `archiveAboveSize="4000"` can I have a numericupdown in winform which can take input this value from user (so that 4000 can be 3000 or 5000) and then set this value in config file accordingly ? ``` ```

Accepted Answer

You can get target by name from NLog configuration and change settings at runtime:

```
var target = (FileTarget)LogManager.Configuration.FindTargetByName("file");
if (target != null)
    target.ArchiveAboveSize = 3000;
```

Unfortunately you can't update NLog configuration file this way - you should do that manually. You can use LINQ for that:

```
var nlogConfigFile = "NLog.config";
var xdoc = XDocument.Load(nlogConfigFile);
var ns = xdoc.Root.GetDefaultNamespace();
var fileTarget = xdoc.Descendants(ns + "target")
         .FirstOrDefault(t => (string)t.Attribute("name") == "file");
fileTarget.Attribute("archiveAboveSize").SetValue(3000);
xdoc.Save(nlogConfigFile);
```

Making NLog config file user define at run time

Solution

Problem