Resolved the runtime error when calling the Dll written in C ++ from the Master HaKu C #

Two errors:

1. Run-Time Check Failure #0-The value of ESP was not properly saved stored ss
Function call. This is usually a result of calling a function declared with one
Calling convention with a function pointer declared with a different calling convention

First, change the C/C ++-> Code Generation (Code Generation)-> Basic Runtime Checks attribute in the dll project attribute to Default.

2. System. AccessViolationException: Try to read or write the protected memory. This usually indicates that other memory is damaged.

Check the functions in your dll. If the function returns a local variable, You need to declare all the returned local variables as static.

3. Note: The function declaration must be consistent between the two languages.

For example, int _ stdcall true_add (int x, int y)

C # CallingConvention = CallingConvention. StdCall

4. Code instance

Cpp:

# Include <stdlib. h>
# Include <stdio. h>

Typedef int (* pfunc) (int, int );
Pfunc myadd;

Int testAdd (int a, int B );

Int _ stdcall add (pfunc add)
{
Printf ("helloworld \ n ");
Myadd = add;

// Myadd = testadd;

// Printf ("% d \ n", add (11,2 ));
Return 2;
}

// Int _ stdcall true_add (int x, int y)
Int _ stdcall true_add (int x, int y)
{
If (myadd)
Return myadd (x, y );
Else
Return 222;
}

Int testadd (int A, int B)
{
Return A + B;
}

Def:

Library
Exports
 
Add @ 1
True_add @ 2
TestAdd @ 3

The above dll is generated under win32

C #:

Class MyTest
{

[DllImport (@ "E: \ WorkSpace \ CPlusPlusCode \ LearnTecknology \ LearnDemoTest \ Debug \ TestLibrary3.dll")]
Public static extern int testAdd (int a, int B );

[DllImport (@ "E: \ WorkSpace \ CPlusPlusCode \ LearnTecknology \ LearnDemoTest \ Debug \ TestLibrary3.dll", EntryPoint = "add", SetLastError = true, CharSet = CharSet. unicode, ExactSpelling = true,
CallingConvention = CallingConvention. StdCall)]
Public static extern int add (pfunc f );

[DllImport (@ "E: \ WorkSpace \ CPlusPlusCode \ LearnTecknology \ LearnDemoTest \ Debug \ TestLibrary3.dll", EntryPoint = "true_add", SetLastError = true, CharSet = CharSet. unicode, ExactSpelling = true,
CallingConvention = CallingConvention. StdCall)]
Public static extern int true_add (int a, int B );

Public delegate int pfunc (int a, int B );

Public int MyFunc (int a, int B)
{
Return a + B-10;
}

Public static pfunc pf;

Public MyTest ()
{

Try
{
Pf = new pfunc (MyFunc );

Int ret = add (pf );

Console. WriteLine ("jjj =" + pf (22, 33) + ", ret =" + ret );

Console. WriteLine (true_add (22, 33 ));

// Int a = testAdd (258, 22 );
// Console. WriteLine (a. ToString ());
}
Catch (Exception ex)
{
Console. WriteLine (ex. ToString ());
}
}
}

// Other common problems with C # Calling C ++
See http://hi.baidu.com/yun0216/item/f7c856d227465738e3108fa3