如何从 DROP FILES 结构中提取拖放文件名

Question

我有一个 window，没有启用 WS_EX_ACCEPTFILES 的控件，当从资源管理器中拖动文件时事件成功触发。我需要做的是将文件提取到矢量中。根据我的阅读，wParam 应该包含文件在 DROPFILES 结构中的位置，但我不知道如何访问它们。

LRESULT CALLBACK StaticWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR 
uIdSubclass, DWORD_PTR dwRefData)
{
    if (uMsg == WM_DROPFILES)
    {
       // extract files here
       vector<string> files;

    }

    return DefSubclassProc(hwnd, uMsg, wParam, lParam);
}

我不需要将它们发送到任何控件，因为我的 window 用于 openGL 应用程序，我只需要将它们保留在列表中，如何实现？

Answer 1

根据 WM_DROPFILES documentation:

Parameters

hDrop

A handle to an internal structure describing the dropped files. Pass this handle to DragFinish, DragQueryFile, or DragQueryPoint() to retrieve information about the dropped files.

lParam

Must be zero.

只需将 wParam 类型转换为 HDROP 并根据需要调用拖放功能，例如：

LRESULT CALLBACK StaticWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    if (uMsg == WM_DROPFILES)
    {
       HDROP hDrop = reinterpret_cast<HDROP>(wParam);

       // extract files here
       vector<string> files;
       char filename[MAX_PATH];

       UINT count = DragQueryFileA(hDrop, -1, NULL, 0);
       for(UINT i = 0; i < count; ++i)
       {
          if (DragQueryFileA(hDrop, i, filename, MAX_PATH))
              files.push_back(filename);
       }

       DragFinish(hDrop);
       return 0;
    }

    return DefSubclassProc(hwnd, uMsg, wParam, lParam);
}

或者：

LRESULT CALLBACK StaticWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    if (uMsg == WM_DROPFILES)
    {
       HDROP hDrop = reinterpret_cast<HDROP>(wParam);

       // extract files here
       vector<string> files;
       string filename;

       UINT count = DragQueryFileA(hDrop, -1, NULL, 0);
       for(UINT i = 0; i < count; ++i)
       {
          UINT size = DragQueryFileA(hDrop, i, NULL, 0);
          if (size > 0)
          {
              filename.resize(size);
              DragQueryFileA(hDrop, i, &filename[0], size+1);
              files.push_back(filename);
          }
       }

       DragFinish(hDrop);
       return 0;
    }

    return DefSubclassProc(hwnd, uMsg, wParam, lParam);
}

如何从 DROP FILES 结构中提取拖放文件名

How do i extract dragged & dropped filenames from a DROPFILES struct

c++

winapi

drag-and-drop