我在编译代码时遇到错误，构建不成功
Error 1 error C2664: 'DWORD GetCurrentDirectoryA(DWORD,LPSTR)' : cannot convert argument 2 from 'wchar_t [260]' to 'LPSTR'
Error 2 error C2664: 'BOOL SetCurrentDirectoryA(LPCSTR)' : cannot convert argument 1 from 'wchar_t *' to 'LPCSTR'
Error 3 error C2664: 'BOOL SetCurrentDirectoryA(LPCSTR)' : cannot convert argument 1 from 'wchar_t [260]' to 'LPCSTR'
Error 4 error C2664: 'HMODULE GetModuleHandleA(LPCSTR)' : cannot convert argument 1 from 'const wchar_t [13]' to 'LPCSTR'
我的cpp代码
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "native_library.h"
#undef UNICODE
#include <windows.h>
//#include "base/files/file_util.h"
//#include "base/strings/stringprintf.h"
//#include "base/strings/utf_string_conversions.h"
//#include "base/threading/thread_restrictions.h"
namespace base {
typedef HMODULE (WINAPI* LoadLibraryFunction)(const wchar_t* file_name);
namespace {
NativeLibrary LoadNativeLibraryHelper(const std::string& library_path,
LoadLibraryFunction load_library_api,
NativeLibraryLoadError* error) {
// LoadLibrary() opens the file off disk.
//ThreadRestrictions::AssertIOAllowed();
// Switch the current directory to the library directory as the library
// may have dependencies on DLLs in this directory.
bool restore_directory = false;
wchar_t current_directory[MAX_PATH];
std::wstring lp = std::wstring(library_path.begin(), library_path.end());
std::wstring plugin_path, plugin_value;
if (GetCurrentDirectory(MAX_PATH,current_directory))
{
const wchar_t *res = wcsrchr(lp.c_str(), '\\');
if (res)
{
plugin_path.assign(lp.c_str(),res);
plugin_value.assign(++res, wcsrchr(res,0));
}
else
plugin_value = lp;
if (!plugin_path.empty())
{
SetCurrentDirectory((wchar_t*)plugin_path.c_str());
restore_directory = true;
}
}
HMODULE module = (*load_library_api)((wchar_t*)plugin_value.c_str());
if (!module && error) {
// GetLastError() needs to be called immediately after |load_library_api|.
error->code = GetLastError();
}
if (restore_directory)
SetCurrentDirectory(current_directory);
return module;
}
} // namespace
std::string NativeLibraryLoadError::ToString() const
{
char buf[32];
return int2char(code, buf);
}
// static
NativeLibrary LoadNativeLibrary(const std::string& library_path,
NativeLibraryLoadError* error) {
return LoadNativeLibraryHelper(library_path, LoadLibraryW, error);
}
NativeLibrary LoadNativeLibraryDynamically(const std::string& library_path) {
typedef HMODULE (WINAPI* LoadLibraryFunction)(const wchar_t* file_name);
LoadLibraryFunction load_library;
load_library = reinterpret_cast<LoadLibraryFunction>(
GetProcAddress(GetModuleHandle(L"kernel32.dll"), "LoadLibraryW"));
return LoadNativeLibraryHelper(library_path, load_library, NULL);
}
// static
void UnloadNativeLibrary(NativeLibrary library) {
FreeLibrary(library);
}
// static
void* GetFunctionPointerFromNativeLibrary(NativeLibrary library,
const char* name) {
return GetProcAddress(library, name);
}
// static
//string16 GetNativeLibraryName(const string16& name) {
// return name + ASCIIToUTF16(".dll");
//}
} // namespace base
请建议出现问题以及如何解决此问题
答案 0 :(得分：0)
错误不言自明。您正在传递wchar_t缓冲区/指针，其中指向char*指针。它们不兼容。请注意，所有错误消息都表明正在调用API函数的A NSI版本。
请勿使用#undef UNICODE！代码负责（un）定义UNICODE（和_UNICODE用于C RTL）。在调用编译器时，项目负责处理它。
通过手动取消定义UNICODE，您强制所有基于TCHAR的Win32 API宏（如您正在调用的那些）映射到ANSI版本而不是Unicode版本。
如果要使用ANSI字符串，请显式调用A NSI函数。如果要使用Unicode字符串，请显式调用W ide函数。停止依赖TCHAR定义。
请改为尝试：
NativeLibrary LoadNativeLibraryHelper(const std::string& library_path,
LoadLibraryFunction load_library_api,
NativeLibraryLoadError* error) {
// LoadLibrary() opens the file off disk.
//ThreadRestrictions::AssertIOAllowed();
// Switch the current directory to the library directory as the library
// may have dependencies on DLLs in this directory.
WCHAR current_directory[MAX_PATH] = {0};
bool restore_directory = false;
// THIS IS NOT THE PROPER WAY TO CONVERT A std::string TO A std::wstring!
// This only works properly for ASCII strings. You need to use
// MultiByteToWideChar() or std::wstring_convert or other equivalent
// to convert ANSI data to UNICODE data. Otherwise, library_path should
// be passed as a std::wstring to begin with...
//
std::wstring lp = std::wstring(library_path.begin(), library_path.end());
std::wstring plugin_path, plugin_value;
const wchar_t *res = wcsrchr(lp.c_str(), L'\\');
if (res)
{
plugin_path.assign(lp.c_str(), res);
plugin_value.assign(++res);
if (!plugin_path.empty())
{
GetCurrentDirectoryW(MAX_PATH, current_directory);
restore_directory = SetCurrentDirectoryW(plugin_path.c_str());
}
}
else
plugin_value = lp;
HMODULE module = (*load_library_api)(plugin_value.c_str());
if (!module && error) {
// GetLastError() needs to be called immediately after |load_library_api|.
error->code = GetLastError();
}
if (restore_directory)
SetCurrentDirectoryW(current_directory);
return module;
}
...
NativeLibrary LoadNativeLibraryDynamically(const std::string& library_path) {
LoadLibraryFunction load_library;
load_library = reinterpret_cast<LoadLibraryFunction>(
GetProcAddress(GetModuleHandleW(L"kernel32.dll"), "LoadLibraryW"));
return LoadNativeLibraryHelper(library_path, load_library, NULL);
}
话虽如此，请勿使用SetCurrentDirectory()来影响搜索依赖DLL的位置！正确的解决方案是使用SetDllDirectory()（XP SP1 +）或AddDllDirectory()（Win8 +）代替。
仅使用SetDllDirectory()：
NativeLibrary LoadNativeLibraryHelper(const std::string& library_path,
LoadLibraryFunction load_library_api,
NativeLibraryLoadError* error) {
// LoadLibrary() opens the file off disk.
//ThreadRestrictions::AssertIOAllowed();
// Include the library directory as the library may have dependencies on
// DLLs in this directory.
// THIS IS NOT THE PROPER WAY TO CONVERT A std::string TO A std::wstring!
// This only works properly for ASCII strings. You need to use
// MultiByteToWideChar() or std::wstring_convert or other equivalent
// to convert ANSI data to UNICODE data. Otherwise, library_path should
// be passed as a std::wstring to begin with...
//
std::wstring lp = std::wstring(library_path.begin(), library_path.end());
std::wstring plugin_path, plugin_value;
bool restore_old_order = false;
const wchar_t *res = wcsrchr(lp.c_str(), L'\\');
if (res)
{
plugin_path.assign(lp.c_str(), res);
plugin_value.assign(++res);
if (!plugin_path.empty())
restore_old_order = SetDllDirectoryW(plugin_path.c_str());
}
else
plugin_value = lp;
HMODULE module = (*load_library_api)(plugin_value.c_str());
if (!module && error) {
// GetLastError() needs to be called immediately after |load_library_api|.
error->code = GetLastError();
}
if (restore_old_order)
SetDllDirectoryW(NULL);
return module;
}
仅使用AddDllDirectory()：
NativeLibrary LoadNativeLibraryHelper(const std::string& library_path,
LoadLibraryFunction load_library_api,
NativeLibraryLoadError* error) {
// LoadLibrary() opens the file off disk.
//ThreadRestrictions::AssertIOAllowed();
// Include the library directory as the library may have dependencies on
// DLLs in this directory.
// THIS IS NOT THE PROPER WAY TO CONVERT A std::string TO A std::wstring!
// This only works properly for ASCII strings. You need to use
// MultiByteToWideChar() or std::wstring_convert or other equivalent
// to convert ANSI data to UNICODE data. Otherwise, library_path should
// be passed as a std::wstring to begin with...
//
std::wstring lp = std::wstring(library_path.begin(), library_path.end());
std::wstring plugin_path, plugin_value;
DLL_DIRECTORY_COOKIE cookie = 0;
const wchar_t *res = wcsrchr(lp.c_str(), L'\\');
if (res)
{
plugin_path.assign(lp.c_str(), res);
plugin_value.assign(++res);
if (!plugin_path.empty())
cookie = AddDllDirectory(plugin_path.c_str());
}
else
plugin_value = lp;
HMODULE module = (*load_library_api)(plugin_value.c_str());
if (!module && error) {
// GetLastError() needs to be called immediately after |load_library_api|.
error->code = GetLastError();
}
if (cookie)
RemoveDllDirectory(cookie);
return module;
}
使用在运行时实际可用的任何一个：
NativeLibrary LoadNativeLibraryHelper(const std::string& library_path,
LoadLibraryFunction load_library_api,
NativeLibraryLoadError* error) {
// LoadLibrary() opens the file off disk.
//ThreadRestrictions::AssertIOAllowed();
// Include the library directory as the library may have dependencies on
// DLLs in this directory.
typedef BOOL (WINAPI* SetDllDirectoryFunction)(LPCWSTR lpPathName);
typedef PVOID DLL_DIRECTORY_COOKIE;
typedef DLL_DIRECTORY_COOKIE (WINAPI* AddDllDirectoryFunction)(PCWSTR NewDirectory);
typedef BOOL(WINAPI* RemoveDllDirectoryFunction)(DLL_DIRECTORY_COOKIE Cookie);
HMODULE hKernel32 = GetModuleHandleW(L"kernel32.dll");
AddDllDirectoryFunction add_dll_directory;
add_dll_directory = reinterpret_cast<AddDllDirectoryFunction>(
GetProcAddress(hKernel32, "AddDllDirectory"));
RemoveDllDirectoryFunction remove_dll_directory;
if (add_dll_directory)
{
remove_dll_directory = reinterpret_cast<RemoveDllDirectoryFunction>(
GetProcAddress(hKernel32, "RemoveDllDirectory"));
}
else
remove_dll_directory = NULL;
SetDllDirectoryFunction set_dll_directory;
if (!(add_dll_directory && remove_dll_directory))
{
set_dll_directory = reinterpret_cast<SetDllDirectoryFunction>(
GetProcAddress(hKernel32, "SetDllDirectoryW"));
}
else
set_dll_directory = NULL;
// THIS IS NOT THE PROPER WAY TO CONVERT A std::string TO A std::wstring!
// This only works properly for ASCII strings. You need to use
// MultiByteToWideChar() or std::wstring_convert or other equivalent
// to convert ANSI data to UNICODE data. Otherwise, library_path should
// be passed as a std::wstring to begin with...
//
std::wstring lp = std::wstring(library_path.begin(), library_path.end());
DLL_DIRECTORY_COOKIE cookie = 0;
bool restore_old_order = false;
std::wstring current_directory;
std::wstring plugin_path, plugin_value;
const wchar_t *res = wcsrchr(lp.c_str(), L'\\');
if (res)
{
plugin_path.assign(lp.c_str(), res);
plugin_value.assign(++res);
if (!plugin_path.empty())
{
if (add_dll_directory && remove_dll_directory)
cookie = (*add_dll_directory)(plugin_path.c_str());
else if (set_dll_directory)
restore_old_order = (*set_dll_directory)(plugin_path.c_str());
else
{
current_directory.resize(MAX_PATH);
GetCurrentDirectoryW(MAX_PATH, ¤t_directory[0]);
if (!SetCurrentDirectoryW(plugin_path.c_str()))
current_directory.clear();
}
}
}
else
plugin_value = lp;
HMODULE module = (*load_library_api)(plugin_value.c_str());
if (!module && error) {
// GetLastError() needs to be called immediately after |load_library_api|.
error->code = GetLastError();
}
if (remove_dll_directory)
{
if (cookie)
(*remove_dll_directory)(cookie);
}
else if (set_dll_directory)
{
if (restore_old_order)
(*set_dll_directory)(NULL);
}
else if (!current_directory.empty())
SetCurrentDirectoryW(current_directory.c_str());
return module;
}