The game has a debug panel which you can add messages to.

Using the panel

To open the panel press F7 in game. You can resize the panel and drag it around. The panel also has a clear button, this will clear all the messages.

Reference the DLL

To be able to use this method of logging you will have to add a reference to the Assembly-CSharp DLL. If you’re not sure how to do this see this guide for Visual Studio or for MonoDevelop. And you’ll also have to add this line at the top of your class to be able to use it.

using ColossalFramework.Plugins;


To send a message to the debug panel you use this code.

DebugOutputPanel.AddMessage(PluginManager.MessageType.Message, "Message");

you can easily create some static methods for logging. It’s also recommended to prefix you log message so that users know were the message came from. For example: “[TreeBrush] Some debug message..”

Logging an objects properties

If you want to print out all the properties of an object, you can use the method below.

using System;
using System.ComponentModel;

public void dumpObject(object myObject)
    string myObjectDetails = "";
    foreach (PropertyDescriptor descriptor in TypeDescriptor.GetProperties(myObject))
        string name = descriptor.Name;
        object value = descriptor.GetValue(myObject);
        myObjectDetails+= name + ": " + value + "\n";
    DebugOutputPanel.AddMessage(PluginManager.MessageType.Message, myObjectDetails);

Other logging methods

There are a few other logging methods that other people made. Here is a list to some of them.