非托管调用
生成非托管DLL
1.使用VS2019创建C++新项目=》选择【空项目】
2.更改项目属性=》常规=》配置类型=》选择【动态库(.dll)】
3.添加源文件=》TestDLL.cpp
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| extern "C" __declspec(dllexport) void testCharAdd(char* buff, int buffSize) {
for (int i = 0; i < buffSize; ++i) {
++buff[i];
}
}
|
4.生成dll
DllImport调用DLL
1.使用VS创建C#新项目选择=》控制台应用程序
2.添加一个类 Usedll.cs
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| using System;
using System.Runtime.InteropServices;
namespace test_csharp
{
class UseDLL
{
[DllImport("TestDLL.dll")]
public extern static void testCharAdd(ref byte buff, UInt32 buffSize);
}
class Program
{
static void Main(string[] args)
{
UInt32 buffsize = 5;
var buff = new byte[buffsize];
UseDLL.testCharAdd(ref buff[0], buffsize);
Console.WriteLine(BitConverter.ToString(buff));
}
}
}
|
CLR托管调用
（可以使用委托类封装或者直接改成委托类都可）
生成托管DLL
1.使用VS2019创建C++新项目=》选择【空项目】
2.更改项目属性=》高级=》公共语言运行时支持=》选择【公共语言运行时支持(/clr)】
3.更改项目属性=》C/C++=》语言=》符合模式=》选择【否(/permissive)】
4.添加头文件=》TestDLL.h
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| #pragma once
public ref class DllClass {
public:
DllClass() {};
~DllClass() {};
void testCharAdd(char* buff, int buffLen);
};
|
5.添加源文件=》TestDLL.cpp
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| #include "TestDLL.h"
void DllClass::testCharAdd(char* buff, int buffLen) {
for (int i = 0; i < buffLen; ++i) {
++buff[i];
}
}
|
6.生成dll
引用调用dll
1.使用VS创建C#新项目选择=》控制台应用程序
2.添加dll的引用=》依赖项=》添加项目引用=》浏览=》选择DLL=》确定
3.更改项目属性=》生成=》勾选【允许不安全代码(F)】
4.然后直接通过对象调用
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| using System;
namespace test_csharp
{
class Program
{
//如果用到指针，需要使用unsafe来修饰类或者函数
unsafe static void Main(string[] args)
{
var sbuff = new sbyte[5];
DllClass dc = new DllClass();
//使用fixed来防止CLR修改地址，使指针所指向的地址不能被改变
fixed (sbyte* pbuff = &sbuff[0])
{
dc.testCharAdd(pbuff, sbuff.Length);
}
byte[] buff = new byte[sbuff.Length];
Buffer.BlockCopy(sbuff, 0, buff, 0, sbuff.Length);
Console.WriteLine(BitConverter.ToString(buff));
}
}
}
|
动态加载
无需引用dll，利用反射进行动态加载调用
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| using System;
using System.Reflection;
using System.Runtime.InteropServices;
namespace test_csharp
{
class Program
{
static void Main(string[] args)
{
var sbuff = new byte[5];
// 按照路径获取dll
Assembly assembly = Assembly.LoadFrom("TestDLL.dll");
// 获取dll中的类
Type dc = assembly.GetType("DllClass");
// 实例化该类
object obj = Activator.CreateInstance(dc);
// 获取该类中的方法，testCharAdd(sbyte*,int)
MethodInfo testCharAdd = dc.GetMethod("testCharAdd");
// 指针需要通过intPtr转换成object，无法通过sbyte*转换成object
IntPtr intPtr = Marshal.AllocHGlobal(sbuff.Length);
Marshal.Copy(sbuff, 0, intPtr, sbuff.Length);
// 反射调用，返回值就是原方法的返回值
testCharAdd.Invoke(obj, new object[] { intPtr, sbuff.Length });
Marshal.Copy(intPtr, sbuff, 0, sbuff.Length);
Marshal.FreeHGlobal(intPtr);
Console.WriteLine(BitConverter.ToString(sbuff));
}
}
}
|
C#和C++的数据类型对应表
| C++ Type |
C# Type |
Size |
| BOOL |
bool |
1 byte |
| BYTE |
byte |
1 byte |
| CHAR |
byte |
1 byte |
| DECIMAL |
Decimal |
16 bytes |
| DOUBLE |
double |
8 bytes |
| DWORD |
uint, UInt32 |
4 bytes |
| FLOAT |
float, single |
4 bytes |
| INT, signed int |
int, Int32 |
4 bytes |
| INT16, signed short int |
short, Int16 |
2 bytes |
| INT32, signed int |
int, Int32 |
4 bytes |
| INT64 |
long, Int64 |
8 bytes |
| LONG |
int, Int32 |
4 bytes |
| LONG32, signed int |
int, Int32 |
4 bytes |
| LONG64 |
long, Int64 |
8 bytes |
| LONGLONG |
long, Int64 |
8 bytes |
| SHORT, signed short int |
short, Int16 |
2 bytes |
| UCHAR, unsigned char |
byte |
1 byte |
| UINT, unsigned int |
uint, UInt32 |
4 bytes |
| UINT16, WORD |
ushort, UInt16 |
2 bytes |
| UINT32, unsigned int |
uint, UInt32 |
4 bytes |
| UINT64 |
ulong, UInt64 |
8 bytes |
| ULONG, unsigned long |
uint, UInt32 |
4 bytes |
| ULONG32 |
uint, UInt32 |
4 bytes |
| ULONG64 |
ulong, UInt64 |
8 bytes |
| ULONGLONG |
ulong, UInt64 |
8 bytes |
| WORD |
ushort |
2 bytes |
| void*, pointers |
IntPtr |
x86=4 bytes, x64=8 bytes |
注意：
C#与C++参数或者返回值数据类型不匹配，会报error：尝试读取或写入受保护的内存等