共享代码：Code:Blocks 对话框 选择文件和选择目录示例,该怎么处理

#include <windows.h>
#include "resource.h"
#include "DirDialog.h"
int   GetFilePath(HWND hWnd, char *szFile);
int   GetPath(HWND hWnd, char *pBuffer);

HINSTANCE hInst;

BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg) {
    case WM_INITDIALOG:
        /*
         * TODO: Add code to initialize the dialog.
         */
        return TRUE;

    case WM_CLOSE:
        EndDialog(hwndDlg, 0);
        return TRUE;

    case WM_COMMAND:
        switch (LOWORD(wParam)) {
            /*
             * TODO: Add more control ID's, when needed.
             */
        case IDC_BTN_QUIT:
            EndDialog(hwndDlg, 0);
            return TRUE;

        case IDC_BTN_TEST:
            MessageBox(hwndDlg, "You clicked \"Test\" button!", "Information", MB_ICONINFORMATION);
            return TRUE;

        case IDC_BTN_OPEN: {
            char szFile[260];       // buffer for file name
            if (! GetFilePath(hwndDlg, szFile))
                return  FALSE;
            MessageBox(NULL, szFile, "选择文件", 0);
            SetWindowText(GetDlgItem(hwndDlg, IDC_EDIT_FILE), szFile);
            SetWindowText(GetDlgItem(hwndDlg, IDC_TEXT), szFile);

        }
        return TRUE;

        case IDC_GETPATH: {
            char szDirPath[260];       // buffer for Dir Path
            if (! GetPath(hwndDlg, szDirPath))
                return  FALSE;

            SetWindowText(GetDlgItem(hwndDlg, IDC_EDIT_FILE), szDirPath);
            SetWindowText(GetDlgItem(hwndDlg, IDC_TEXT), szDirPath);
        }
        return TRUE;

        case IDC_DIRBROWSER: {
            CDirDialog dir;
            if (dir.DoBrowse(hwndDlg)) {

                SetWindowText(GetDlgItem(hwndDlg, IDC_EDIT_FILE), dir.GetPath());
                MessageBox(NULL, dir.GetPath(), "选择文件夹", NULL);
            }
        }
        return TRUE;


        }
    }

    return FALSE;
}


int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    hInst = hInstance;

    // The user interface is a modal dialog box
    return DialogBox(hInstance, MAKEINTRESOURCE(DLG_MAIN), NULL, (DLGPROC)DialogProc);
}



// 选择一个目录
int   GetPath(HWND hWnd, char *pBuffer)
{
    BROWSEINFO   bf;
    LPITEMIDLIST   lpitem;
    memset(&bf, 0, sizeof(BROWSEINFO));
    bf.hwndOwner = hWnd;
    bf.lpszTitle = "选择路径 ";
    bf.ulFlags = BIF_RETURNONLYFSDIRS;   //属性你可自己选择
    lpitem = SHBrowseForFolder(&bf);
    if (lpitem == NULL)  //如果没有选择路径则返回   0
        return   0;

    //如果选择了路径则复制路径,返回路径长度

    SHGetPathFromIDList(lpitem, pBuffer);
    return   lstrlen(pBuffer);
}


// 选择一个文件
int   GetFilePath(HWND hWnd, char *szFile)
{

    OPENFILENAME ofn;       // common dialog box structure
    // Initialize OPENFILENAME
    ZeroMemory(&ofn, sizeof(ofn));
    ofn.lStructSize = sizeof(ofn);
    ofn.hwndOwner = hWnd;
    ofn.lpstrFile = szFile;
    // Set lpstrFile[0] to '\0' so that GetOpenFileName does not
    // use the contents of szFile to initialize itself.
    ofn.lpstrFile[0] = '\0';
    ofn.nMaxFile = 260; // 本来sizeof(szFile);
    ofn.lpstrFilter = "All\0*.*\0Text\0*.TXT\0";
    ofn.nFilterIndex = 1;
    ofn.lpstrFileTitle = NULL;
    ofn.nMaxFileTitle = 0;
    ofn.lpstrInitialDir = NULL;
    ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;

    // Display the Open dialog box.
    GetOpenFileName(&ofn);
    return   lstrlen(szFile);
}

/////////////////////////////////////////////////
// DirDialog.h文件

#ifndef __DIRDIALOG_H_
#define __DIRDIALOG_H_

#include <shlobj.h>

class CDirDialog
{
public:
    CDirDialog();
    // 显示对话框
    BOOL DoBrowse(HWND hWndParent, LPCTSTR pszTitle = NULL);
    // 取得用户选择的目录名称
    LPCTSTR GetPath() { return m_szPath; }

protected:
    BROWSEINFOA m_bi; 

    // 用来接受用户选择目录的缓冲区
    char m_szDisplay[MAX_PATH];
    char m_szPath[MAX_PATH];
};

CDirDialog::CDirDialog()
{
    memset(&m_bi, 0, sizeof(m_bi));

    m_bi.hwndOwner = NULL;     
    m_bi.pidlRoot = NULL;             
    m_bi.pszDisplayName = m_szDisplay; 
    m_bi.lpszTitle = NULL;             
    m_bi.ulFlags = BIF_RETURNONLYFSDIRS;
    
    m_szPath[0] = '\0';
}

BOOL CDirDialog::DoBrowse(HWND hWndParent, LPCTSTR pszTitle)
{
    if(pszTitle == NULL)
        m_bi.lpszTitle = "选择目标文件夹";
    else
        m_bi.lpszTitle = pszTitle;

    m_bi.hwndOwner = hWndParent;
    LPITEMIDLIST pItem = ::SHBrowseForFolder(&m_bi);
    if(pItem != 0)
    {
        ::SHGetPathFromIDList(pItem, m_szPath);
        return TRUE;
    }

    return FALSE;
}

#endif //__DIRDIALOG_H_