fixed (void** ppInputBlock = &pTwinCatInputs)中写法在c#里啥用？

[strife013]

fixed (void** ppInputBlock = &pTwinCatInputs)

[小心眼]

fixed 语句设置指向托管变量的指针并在 statement 执行期间“钉住”该变量。如果没有 fixed 语句，则指向可移动托管变量的指针的作用很小，因为垃圾回收可能不可预知地重定位变量。C# 编译器只允许在 fixed 语句中分配指向托管变量的指针。

// statements_fixed.cs
// compile with: /unsafe
using System;

class Point
{ 
    public int x, y; 
}

class FixedTest 
{
    // Unsafe method: takes a pointer to an int.
    unsafe static void SquarePtrParam (int* p) 
    {
        *p *= *p;
    }

    unsafe static void Main() 
    {
        Point pt = new Point();
        pt.x = 5;
        pt.y = 6;
        // Pin pt in place:

// assume class Point { public int x, y; }
// pt is a managed variable, subject to garbage collection.
//Point pt = new Point();
// Using fixed allows the address of pt members to be taken, and "pins" pt so it isn't relocated.

        fixed (int* p = &pt.x) 
        {
            SquarePtrParam (p);
        }
        // pt now unpinned
//执行完语句中的代码后，任何固定变量都被解除固定并受垃圾回收的制约。因此，不要指向 fixed 语句之外的那些变量。
        Console.WriteLine ("{0} {1}", pt.x, pt.y);
    }
}

你最好再看下
固定变量和可移动变量

[杨友山]

我也没见过这种写法啊

[showjim]

pTwinCatInputs应该在初始化的之前fixed

        unsafe static void voidPoint(void* pTwinCatInputs)
        {
            void** ppInputBlock = &pTwinCatInputs;
        }

[csproj]

google “c# unsafe”