1. 如果函数只有传入参数,比如:
C/C++ Code Copy Code To Clipboard
int__declspec(dllexport) test(constint N)
{
return N+10;
}
对应的C#代码为:
C# Code Copy Code To Clipboard
[DllImport("test.dll", EntryPoint = "#1")]
publicstaticexternint test(int m);
privatevoid button1_Click(object sender, EventArgs e)
{
textBox1.Text= test(10).ToString();
}
2. 如果函数有传出参数,比如:
C/C++ Code Copy Code To Clipboard
//C++
void__declspec(dllexport) test(constint N, int& Z)
{
Z=N+10;
}
对应的C#代码:
C# Code Copy Code To Clipboard
[DllImport("test.dll", EntryPoint = "#1")]
publicstaticexterndouble test(int m, refint n);
privatevoid button1_Click(object sender, EventArgs e)
{
int N = 0;
test1(10, ref N);
textBox1.Text= N.ToString();
}
3. 带传入数组:
C/C++ Code Copy Code To Clipboard
void__declspec(dllexport) test(constint N, constint n[], int& Z)
{
for (int i=0; i<N; i++)
{
Z+=n[i];
}
}
C#代码:
C# Code Copy Code To Clipboard
[DllImport("test.dll", EntryPoint = "#1")]
publicstaticexterndouble test(int N, int[] n, refint Z);
privatevoid button1_Click(object sender, EventArgs e)
{
int N = 0;
int[] n;
n = newint[10];
for (int i = 0; i < 10; i++)
{
n[i] = i;
}
test(n.Length, n, ref N);
textBox1.Text= N.ToString();
}
4. 带传出数组:
C++不能直接传出数组,只传出数组指针,
C/C++ Code Copy Code To Clipboard
void__declspec(dllexport) test(constint M, constint n[], int *N)
{
for (int i=0; i<M; i++)
{
N[i]=n[i]+10;
}
}
对应的C#代码:
C# Code Copy Code To Clipboard
[DllImport("test.dll", EntryPoint = "#1")]
publicstaticexternvoid test(int N, int[] n, [MarshalAs(UnmanagedType.LPArray,SizeParamIndex=1)] int[] Z);
privatevoid button1_Click(object sender, EventArgs e)
{
int N = 1000;
int[] n, Z;
n = newint[N];Z = newint[N];
for (int i = 0; i < N; i++)
{
n[i] = i;
}
test(n.Length, n, Z);
for (int i=0; i<Z.Length; i++)
{
textBox1.AppendText(Z[i].ToString()+"n");
}
}
这里声明函数入口时,注意这句 [MarshalAs(UnmanagedType.LPArray,SizeParamIndex=1)] int[] Z
在C#中数组是直接使用的,而在C++中返回的是数组的指针,这句用来转化这两种不同的类型.
关于MarshalAs的参数用法以及数组的Marshaling,可以参见这篇转帖的文章: http://www.kycis.com/blog/read.php?21