德尔福2010年使用C / C ++ DLL [英] Using C/C++ DLL in Delphi 2010

问题描述

我想用从ssdeep DLL（http://ssdeep.sourceforge.net/）。 API是：

I want to use dll from ssdeep (http://ssdeep.sourceforge.net/). The API is:

INT fuzzy_hash_buf（无符号字符* buf中，uint32_t的buf_len，字符*结果）;

int fuzzy_hash_buf(unsigned char *buf, uint32_t buf_len, char *result);

然后在Delphi中，我把它写这样的：

then in Delp i write it like this:

功能fuzzy_hash_buf（BUF：PBYTE; buf_len：红衣主教;结果：PAnsiChar）：整数; STDCALL;外部fuzzy.dll'名'fuzzy_hash_buf';

function fuzzy_hash_buf(buf : Pbyte; buf_len : Cardinal; result : PAnsiChar): integer; stdcall; external 'fuzzy.dll' name 'fuzzy_hash_buf';

如何使用该功能在Delphi？

How to use that function in Delphi?

谢谢！

推荐答案

如果 fuzzy.dll 导出函数 fuzzy_hash_buf 与C声明

int fuzzy_hash_buf(unsigned char *buf, uint32_t buf_len, char *result);

那么你是正确的，德尔福宣布将

then you are right that the Delphi declaration would be

function fuzzy_hash_buf(buf: PAnsiChar; buf_len: cardinal; result: PAnsiChar):
  integer;

要在Delphi中使用此，一个单位中的接口部分，写

To use this in Delp in the interface section of a unit, write

function fuzzy_hash_buf(buf: PAnsiChar; buf_len: cardinal; result: PAnsiChar):
  integer; stdcall;

然后，在实施非常相同的单元部分，您不实现自己的功能，而是指向外部DLL：

Then, in the implementation section of the very same unit, you do not implement the function yourself, but rather point to the external DLL:

function fuzzy_hash_buf; external 'fuzzy.dll' name 'fuzzy_hash_buf`

请注意，您不必重新声明的参数，结果类型和调用约定（ STDCALL ）。

Notice that you do not have to redeclare the parameters, the result type, and the calling convention (stdcall).

现在你可以使用这个功能，就好像它是本单位的实际功能。比如，你可以写

Now you can use this function as if it were an actual function of this unit. For instance, you might write

val := fuzzy_hash_buf(buf, len, output);

从使用任何单位中，你声明的单元 fuzzy_hash_buf 。

我害怕，我不与不够熟悉的CreateFileMapping 功能。然而，阅读MSDN文档后，我相信你能做到

I am afraid that I am not familiar enough with the CreateFileMapping function. However, after reading the MSDN documentation, I believe that you can do

var
  buf: PAnsiChar;

buf := MapViewOfFile(FFileMappingHandle, FILE_MAP_READ, 0, 0, 0);

// Now, if I have understood MapViewOfFile correctly, buf points to the first byte of the file.

var
  StatusCode: integer;
  TheResult: PAnsiChar;

GetMem(TheResult, FUZZY_MAX_RESULT);

StatusCode := fuzzy_has_buf(buf, FFileSize, TheResult);

// Now TheResult points to the first byte (character) of the output of the function.

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