C#函数指针？
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C# function pointer?
提问by user1276333
I'm having a problem with C#, I'd like to get a pointer of a method in my code, but it seems impossible. I need the pointer of the method because I want to no-op it using WriteProcessMemory. How would I get the pointer?
我在使用 C# 时遇到了问题，我想在我的代码中获取一个方法的指针，但这似乎是不可能的。我需要该方法的指针，因为我想使用 WriteProcessMemory 不操作它。我将如何获得指针？
Example code
示例代码
main()
{
function1();
function2();
}
function1()
{
//get function2 pointer
//use WPM to nop it (I know how, this is not the problem)
}
function2()
{
Writeline("bla"); //this will never happen because I added a no-op.
}
回答by Dai
EDIT: I misread your question and didn't see the bit about wanting to NOP a statement with doing raw memory manipulation. I'm afraid this isn't recommended because, as Raymond Chen says, the GC moves stuff around in memory (hence the 'pinned' keyword in C#). You probably can do it with reflection, but your question suggests you don't have a strong grasp of the CLR. Anyway, back to my original irrelevant answer (where I thought you just wanted information on how to use delegates):
编辑：我误读了您的问题，并没有看到想要通过执行原始内存操作来 NOP 声明的一点。恐怕不推荐这样做，因为正如 Raymond Chen 所说，GC 在内存中移动内容（因此是 C# 中的“pinned”关键字）。您可能可以通过反射来做到这一点，但是您的问题表明您对 CLR 没有很好的掌握。无论如何，回到我最初的不相关的答案（我以为你只是想了解如何使用委托的信息）：
C# isn't a scripting language ;)
C# 不是脚本语言 ;)
Anyway, C# (and the CLR) has "function pointers" - except they're called "delegates" and are strongly typed, which means you need to define the function's signature in addition to the function you want to call.
无论如何，C#（和 CLR）具有“函数指针”——除了它们被称为“委托”并且是强类型的，这意味着除了要调用的函数之外，您还需要定义函数的签名。
In your case, you'd have something like this:
在你的情况下，你会有这样的事情：
public static void Main(String[] args) {
Function1();
}
// This is the "type" of the function pointer, known as a "delegate" in .NET.
// An instance of this delegate can point to any function that has the same signature (in this case, any function/method that returns void and accepts a single String argument).
public delegate void FooBarDelegate(String x);
public static void Function1() {
// Create a delegate to Function2
FooBarDelegate functionPointer = new FooBarDelegate( Function2 );
// call it
functionPointer("bla");
}
public static void Function2(String x) {
Console.WriteLine(x);
}
回答by Mahdi
I'd wish it is useful
我希望它有用
class Program
{
static void Main(string[] args)
{
TestPointer test = new TestPointer();
test.function1();
}
}
class TestPointer
{
private delegate void fPointer(); // point to every functions that it has void as return value and with no input parameter
public void function1()
{
fPointer point = new fPointer(function2);
point();
}
private void function2()
{
Console.WriteLine("Bla");
}
}
回答by Mike Zboray
回答by outbred
I know this is very old, but an example of something like a function pointer in C# would be like this:
我知道这已经很老了，但是 C# 中函数指针之类的示例如下：
class Temp
{
public void DoSomething() {}
public void DoSomethingElse() {}
public void DoSomethingWithAString(string myString) {}
public bool GetANewCat(string name) { return true; }
}
...and then in your main or wherever:
...然后在您的主要或任何地方：
var temp = new Temp();
Action myPointer = null, myPointer2 = null;
myPointer = temp.DoSomething;
myPointer2 = temp.DoSomethingElse;
Then to call the original function,
然后调用原来的函数，
myPointer();
myPointer2();
If you have arguments to your methods, then it's as simple as adding generic arguments to your Action:
如果您的方法有参数，那么就像向 Action 添加通用参数一样简单：
Action<string> doItWithAString = null;
doItWithAString = temp.DoSomethingWithAString;
doItWithAString("help me");
Or if you need to return a value:
或者，如果您需要返回一个值：
Func<string, bool> getACat = null;
getACat = temp.GetANewCat;
var gotIt = getACat("help me");
回答by Thiren Govender
public string myFunction(string name)
{
return "Hello " + name;
}
public string functionPointerExample(Func<string,string> myFunction)
{
return myFunction("Theron");
}
Func functionName.. use this to pass methods around. Makes no sense in this context but thats basically how you would use it
Func functionName.. 使用它来传递方法。在这种情况下没有意义，但这基本上就是你将如何使用它
