1.对话框属性中把:Accept Files设置为TRUE，或者ModifyStyleEx(0, WS_EX_ACCEPTFILES);
2.在对话框中添加一个ListBox控件,并关联成员变量:m_lstTest;
3.在ListBox属性中同样把:Accept Files设置为TRUE;
4.添加消息响应:
MESSAGE_HANDLER(WM_DROPFILES, OnDropFiles)
LRESULT OnDropFiles(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/);
5.实现:
LRESULT CMainDlg::OnDropFiles(UINT /*uMsg*/, WPARAM wParam, LPARAM /*lParam*/, BOOL& /*bHandled*/)
{
HDROP hDrop = (HDROP)wParam;
wchar_t buf[MAX_PATH] = {0};
int nFileCount = DragQueryFile(hDrop, 0xFFFFFFFF, buf, MAX_PATH);//经检MSDN,0xFFFFFFFF返回托拽文件个数
if(nFileCount > 0)
{
for(int i = 0; i < nFileCount; i++)
{
memset(buf, 0, MAX_PATH);
DragQueryFile(hDrop, i, buf, MAX_PATH);
RECT rtTest;
m_lstTest.GetWindowRect(&rtTest);
POINT pt;
GetCursorPos(&pt);
if(::PtInRect(&rtTest, pt))
{
m_lstTest.AddString(buf);
}
}
}
DragFinish(hDrop);
return 0;
}
在实际工作中还会遇到另一个问题,如果编译选项中UAC选择的是requireAdministrator的话(默认是:asInvoker),WIN7中托拽文件不成功,大概原因是低权限无法向高权限发消息引起的问题.
解决方案是(借用别人方法):
typedef BOOL (WINAPI *_ChangeWindowMessageFilter)( UINT , DWORD);
BOOL AllowMeesageForVista(UINT uMessageID, BOOL bAllow)//注册Vista全局消息
{
BOOL bResult = FALSE;
HMODULE hUserMod = NULL;
//vista and later
hUserMod = LoadLibrary( L"user32.dll" );
if( NULL == hUserMod )
{
return FALSE;
}
_ChangeWindowMessageFilter pChangeWindowMessageFilter = (_ChangeWindowMessageFilter)GetProcAddress( hUserMod, "ChangeWindowMessageFilter" );
if( NULL == pChangeWindowMessageFilter )
{
return FALSE;
}
bResult = pChangeWindowMessageFilter( uMessageID, bAllow ? 1 : 2 );//MSGFLT_ADD: 1, MSGFLT_REMOVE: 2
if( NULL != hUserMod )
{
FreeLibrary( hUserMod );
}
return bResult;
}
在OnInitDialog中加入三句:
LRESULT OnInitDialog(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
{
...
AllowMeesageForVista(WM_DROPFILES, TRUE);
AllowMeesageForVista(WM_COPYDATA, TRUE);
AllowMeesageForVista(0x0049, TRUE);
...
}