Harmony是一个开放源代码库，旨在在运行时替换、修饰或修改任何现有C＃方法。它的主要用在用Mono语言编写的游戏和插件，但是该技术可以与任何.NET版本一起使用。它还照顾对同一方法的多次更改（它们累积而不是覆盖）。
它为每个原始方法创建DynamicMethod方法，并向其织入代码，该代码在开始和结束时调用自定义方法。它还允许您编写过滤器来处理原始的IL代码，从而可以对原始方法进行更详细的操作。
文档可以在这里找到。
- 最新2.0版本终于支持.net core.
- Harmony支持手动（Patch）和自动（PatchAll）织入
- 织入位置可以是执行前（Prefix）、执行后（Postfix）和终结嚣（Finalizer），也可以更详细的手动修改IL（Transpiler）
- 支持构造函数、Getter/Setter、虚/非虚方法、静态方法
手动模式
class NoneGenericClass
{
private readonly bool _isRunning = true;
private int _counter = ; public int DoSomething()
{
Console.WriteLine(nameof(DoSomething)); if (_isRunning)
{
_counter++;
}
return _counter * ;
} public static int DoSomething2()
{
Console.WriteLine(nameof(DoSomething2)); return ;
} public IEnumerable<int> GetNumbers()
{
Console.WriteLine(nameof(GetNumbers)); yield return ;
yield return ;
yield return ;
}
} static class NoneGenericClassPatcher
{
public static void Patch()
{
var harmony = new Harmony(nameof(NoneGenericClassPatcher)); harmony.Patch(typeof(NoneGenericClass).GetMethod(nameof(NoneGenericClass.DoSomething)),
new HarmonyMethod(GetMethod(nameof(MyPrefix))),
new HarmonyMethod(GetMethod(nameof(MyPostfix))),
new HarmonyMethod(GetMethod(nameof(MyTranspiler))),
new HarmonyMethod(GetMethod(nameof(MyFinalizer)))); Console.WriteLine(new NoneGenericClass().DoSomething());
Console.WriteLine(); harmony.Patch(typeof(NoneGenericClass).GetMethod(nameof(NoneGenericClass.GetNumbers)),
new HarmonyMethod(GetMethod(nameof(MyPrefix))),
new HarmonyMethod(GetMethod(nameof(PassthroughPostfix))),
new HarmonyMethod(GetMethod(nameof(MyTranspiler))),
new HarmonyMethod(GetMethod(nameof(MyFinalizer)))); Console.WriteLine(string.Join(", ", new NoneGenericClass().GetNumbers()));
Console.WriteLine(); harmony.Patch(typeof(NoneGenericClass).GetMethod(nameof(NoneGenericClass.DoSomething2)),
new HarmonyMethod(GetMethod(nameof(StaticPrefix))),
new HarmonyMethod(GetMethod(nameof(MyPostfix))),
new HarmonyMethod(GetMethod(nameof(MyTranspiler))),
new HarmonyMethod(GetMethod(nameof(MyFinalizer)))); Console.WriteLine(NoneGenericClass.DoSomething2());
} static MethodInfo GetMethod(string name) => typeof(NoneGenericClassPatcher).GetMethod(name, BindingFlags.Static | BindingFlags.Public); public static bool MyPrefix(out Stopwatch __state, ref bool ____isRunning)
{
__state = Stopwatch.StartNew();
Console.WriteLine($"{nameof(MyPrefix)} {____isRunning}"); return true;
} public static bool StaticPrefix(out Stopwatch __state)
{
__state = Stopwatch.StartNew();
Console.WriteLine($"{nameof(StaticPrefix)}"); return true;
} public static void MyPostfix(Stopwatch __state, ref int __result, MethodBase __originalMethod)
{
Console.WriteLine($"{__state.ElapsedMilliseconds} {__result++}");
Console.WriteLine(nameof(MyPostfix));
} public static IEnumerable<int> PassthroughPostfix(IEnumerable<int> values)
{
yield return ;
foreach (var value in values)
if (value > )
yield return value * ;
yield return ;
Console.WriteLine(nameof(PassthroughPostfix));
} // looks for STDFLD someField and inserts CALL MyExtraMethod before it
public static IEnumerable<CodeInstruction> MyTranspiler(IEnumerable<CodeInstruction> instructions)
{
Console.WriteLine(nameof(MyTranspiler));
//var found = false;
foreach (var instruction in instructions)
{
//if (instruction.opcode == OpCodes.Stfld && instruction.operand == f_someField)
//{
// yield return new CodeInstruction(OpCodes.Call, m_MyExtraMethod);
// found = true;
//}
yield return instruction;
}
//if (found == false)
// ReportError("Cannot find <Stdfld someField> in OriginalType.OriginalMethod");
} public static void MyFinalizer(Exception __exception)
{
Console.WriteLine($"{nameof(MyFinalizer)} {__exception}");
}
}
自动模式
public class Annotations
{
private readonly bool _isRunning; public IEnumerable<int> GetNumbers()
{
Console.WriteLine(nameof(GetNumbers)); yield return ;
yield return ;
yield return ;
}
} [HarmonyPatch(typeof(Annotations))]
[HarmonyPatch(nameof(Annotations.GetNumbers))]
public class AnnotationsPatcher
{
static AccessTools.FieldRef<Annotations, bool> isRunningRef =
AccessTools.FieldRefAccess<Annotations, bool>("_isRunning"); public static void Patch()
{
var harmony = new Harmony(nameof(AnnotationsPatcher)); harmony.PatchAll(); Console.WriteLine(string.Join(", ", new Annotations().GetNumbers()));
} static bool Prefix(Annotations __instance)
{
Console.WriteLine("Prefix"); return true;
} /// <summary>Not working</summary>
static IEnumerable<int> Postfix(IEnumerable<int> values)
{
yield return ;
foreach (var value in values)
if (value > )
yield return value * ;
yield return ;
Console.WriteLine(nameof(Postfix));
} // looks for STDFLD someField and inserts CALL MyExtraMethod before it
public static IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions)
{
Console.WriteLine(nameof(Transpiler));
//var found = false;
foreach (var instruction in instructions)
{
//if (instruction.opcode == OpCodes.Stfld && instruction.operand == f_someField)
//{
// yield return new CodeInstruction(OpCodes.Call, m_MyExtraMethod);
// found = true;
//}
yield return instruction;
}
//if (found == false)
// ReportError("Cannot find <Stdfld someField> in OriginalType.OriginalMethod");
}
}
运行代码
static void Main(string[] args)
{
NoneGenericClassPatcher.Patch();
Console.WriteLine();
AnnotationsPatcher.Patch();
}
输出结果
MyTranspiler
MyPrefix True
DoSomething MyPostfix
MyFinalizer MyTranspiler
MyPrefix True
MyFinalizer
GetNumbers
, , MyTranspiler
StaticPrefix
DoSomething2 MyPostfix
MyFinalizer Transpiler
Prefix
GetNumbers
Postfix
, , ,