如何使用winapi创建一个选择多个文件的对话框？

Question

如何创建具有多文件选择可能性的正常文件打开对话框？我正在使用 GetOpenFileName() 函数打开一个对话框。

如果我将OFN_ALLOWMULTISELECT 设置为Flags，它会给我这样的对话框：

这不是我想要的，原因有很多。

我希望它看起来像这样：

是否有任何简单/容易的解决方案，还是我必须自己重新创建整个对话框？

编辑：这是我打开对话框的代码：

OPENFILENAME ofn;
ZeroMemory(&ofn, sizeof(ofn));
ofn.lStructSize = sizeof(ofn);
ofn.hwndOwner = hWnd;
ofn.lpstrFile = "selectfile";
ofn.nMaxFile = 260;
ofn.lpstrFilter = "t1\0test1\0t2\0test2\0";
ofn.lpstrFileTitle = NULL;
ofn.nMaxFileTitle = 0;
ofn.lpstrInitialDir = NULL;
ofn.nFilterIndex = 1;
ofn.Flags = OFN_ALLOWMULTISELECT | OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
ofn.lpstrTitle = TEXT("title");
GetOpenFileName(&ofn);

Answer 1

您必须包含OFN_EXPLORER 标志以及OFN_ALLOWMULTISELECT 标志。

使用GetOpenFileName 的缺点是您必须为所选文件分配缓冲区。因此这意味着您需要在显示对话框之前决定缓冲区应该有多大。这具有限制可以选择的文件数量的效果。

在 Vista 及更高版本上，您可以使用 common item dialog 代替 GetOpenFileName。新的公共项目对话框的许多改进之一是调用者不分配缓冲区。因此可以选择的文件数量没有限制。

---

您的代码的一个相当严重的问题是您没有分配缓冲区。你写道：

ofn.lpstrFile = "selectfile";

提供只读字符串文字而不是可变缓冲区。在继续之前，您需要解决该问题。此代码显示了显示支持多选的文件对话框所需的最低限度：

OPENFILENAME ofn = { sizeof ofn };
wchar_t file[1024];
file[0] = '\0';
ofn.lpstrFile = file;
ofn.nMaxFile = 1024;
ofn.Flags = OFN_ALLOWMULTISELECT | OFN_EXPLORER;
GetOpenFileName(&ofn);

Answer 2

使用多选打开文件对话框，工作示例

#include <windows.h>
#include <stdio.h>

LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
OPENFILENAME ofn={0};
char szFile[MAX_PATH + 1] = {0};
char szDirect[MAX_PATH + 1] = {0}; 
int fCount=0;   

switch(iMsg)
    {
    case WM_CREATE:
    return 0;

    case WM_KEYDOWN:
    //(int)wParam - virtual key code, lParam - key data
    switch((int)wParam)
        {
        case VK_ESCAPE:
        PostQuitMessage(0);
        break;
        
        case VK_F1:
        ofn.lStructSize = sizeof(ofn);
        ofn.hwndOwner = hwnd;   
        ofn.lpstrFile = szDirect;
        *(ofn.lpstrFile) = 0;
        ofn.nMaxFile = MAX_PATH;
        
        //file type filter, \0 - null character (end of string)
        ofn.lpstrFilter = "All Files\0*.*\0Compressed Zip\0*.ZIP\0Text .txt\0*.TXT\0";
        
        ofn.nFilterIndex = 1;
        ofn.lpstrFileTitle = szFile;
        *(ofn.lpstrFileTitle) = 0;
        ofn.nMaxFileTitle = sizeof(szFile);
        ofn.lpstrInitialDir = NULL;
        ofn.Flags = OFN_EXPLORER | OFN_ALLOWMULTISELECT;

        //show dialog Open
        if (GetOpenFileName(&ofn)==TRUE) 
        {
        printf("files selected\n");
        char* ptr = ofn.lpstrFile;
        ptr[ofn.nFileOffset-1] = 0;
        printf("Directory path: %s\n", ptr);
        ptr += ofn.nFileOffset;
        
        while (*ptr)
            {
            fCount++;           
            printf("File: %i %s\n", fCount, ptr);
            ptr += (lstrlen(ptr)+1);
            }
            
        printf("\n");               
        printf("selected %i files\n", fCount);  
        }
        else
        {
        printf("no files selected\n");
        }
        
        break;
        case VK_F2:
        //GetSaveFileName() for example 
        break;          
        }
    break;  

    case WM_DESTROY:
    PostQuitMessage(0);
    return 0;
    }

return DefWindowProc(hwnd, iMsg, wParam, lParam);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
//class name
static char szAppName[] = "HelloWin";
HWND hwnd;
MSG msg;

//declare class variable wc 
WNDCLASS wc;
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0; wc.cbWndExtra = 0; wc.hInstance = hInstance; 
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION); 
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground =(HBRUSH)GetStockObject(WHITE_BRUSH);
wc.lpszMenuName = NULL;
wc.lpszClassName = szAppName;

//register class variable wc 
RegisterClass(&wc);

//create window
hwnd = CreateWindow
(szAppName, "Standard Window", WS_OVERLAPPEDWINDOW, 
100, 100, 600, 400, NULL, NULL, hInstance, NULL);

//show window
ShowWindow(hwnd, iCmdShow);
UpdateWindow(hwnd);

while(GetMessage(&msg, NULL, 0, 0))
  {
  TranslateMessage(&msg);
  DispatchMessage(&msg);
  }
return msg.wParam;
}