I made a stupid mistake today.

I need to get a file path, so I use GetOpenFileName .Following is the definition:

BOOL GetOpenFileName(   LPOPENFILENAME lpofn);

According to the description in MSDN,I just need to fill the OPENFILENAME  structure.And here is my code:

char szFilePath[MAX_PATH];
OPENFILENAME  stOpenFileName;
BOOL            zRet;
RtlZeroMemory(&stOpenFileName ,sizeof(OPENFILENAME));
stOpenFileName.lStructSize = sizeof(OPENFILENAME);
stOpenFileName.lpstrFilter = “驱动(*.sys)\0\0″;
stOpenFileName.lpstrFile = szFilePath;
stOpenFileName.nMaxFile = MAX_PATH;
stOpenFileName.Flags = OFN_FILEMUSTEXIST;
zRet = GetOpenFileName(&stOpenFileName);

The code above can run successfully,but it never shows the file-choosen dialog.

Then  I search for  the usage  of  GetOpenFileName,But I got nothing.

After about an hour ,I ran the program and get the dialog with messy code. So I rechecked  my code and  read MSDN’s

description about OPENFILENAME .And I found that :

lpstrFilter

Long pointer to a buffer that contains pairs of null-terminated filter strings. The last string in the buffer must be terminated by two NULL characters.

Finally,I descovered that I’ve forgot to initialize szFilePath  .After I add :

RtlZeroMemory(szFilePath ,sizeof(char)*MAX_PATH);

The dialog appeared.

Following is the correct code:

int main()
{
char szFilePath[MAX_PATH];
OPENFILENAME  stOpenFileName;
BOOL            zRet;
RtlZeroMemory(&stOpenFileName ,sizeof(OPENFILENAME));
RtlZeroMemory(szFilePath ,sizeof(char)*MAX_PATH);
stOpenFileName.lStructSize = sizeof(OPENFILENAME);;
stOpenFileName.lpstrFilter = “驱动(*.sys)\0\0″;
stOpenFileName.lpstrFile = szFilePath;
stOpenFileName.nMaxFile = MAX_PATH;
stOpenFileName.Flags = OFN_FILEMUSTEXIST;
zRet = GetOpenFileName(&stOpenFileName);
MessageBox(NULL ,stOpenFileName.lpstrFile ,NULL ,0);
return 0;
}