VC判斷一個文件為目錄的方法

2020-01-26 15:11:54

字體：大中小

來源：轉載

供稿：網友

本文實例講述了VC判斷一個文件為目錄的方法，分享給大家供大家參考。具體實現方法如下：

這是一個自定義函數，用于判斷一個文件是否為目錄：

/**
 * check whether a file is a directory
 @return true if is a directory, else false(if file not exists, false)
 */
__declspec(dllexport) bool IsDirectory(const char* filename)
{
 
  DWORD dwAttr = ::GetFileAttributes(filename);  //得到文件屬性
 
  if (dwAttr == 0xFFFFFFFF)    // 文件或目錄不存在
    return false;
  else if (dwAttr&FILE_ATTRIBUTE_DIRECTORY)  // 如果是目錄
    return true; 
  else
    return false;
}

以下是GetFileAttribute定義，摘自msdn：

Retrieves a set of FAT file system attributes for a specified file or directory.得到FAT文件系統的文件屬性

Parameters

lpFileName

The name of the file or directory.In the ANSI version of this function, the name is limited to MAX_PATH characters. To extend this limit to 32,767 wide characters, call the Unicode version of the function and prepend "http://?/" to the path. For more information, see Naming a File.文件名或目錄名。最大長度為系統的文件名最大長度。如果是unicode環境，需要調用這個函數的unicode版本。

Return Value

If the function succeeds, the return value contains the attributes of the specified file or directory.
如果函數成功了，返回值會包含以下文件屬性：
If the function fails, the return value is INVALID_FILE_ATTRIBUTES. To get extended error information, call GetLastError.
如果函數失敗，返回值是INVALID_FILE_ATTRIBUTES. 可以通過GetLastError獲取更詳細的出錯信息
The attributes can be one or more of the following values.
文件屬性可以是下列值的一個或多個的組合。

Return code/value	Description
FILE_ATTRIBUTE_ARCHIVE 32 0x20	A file or directory that is an archive file or directory. Applications use this attribute to mark files for backup or removal. 存檔文件
FILE_ATTRIBUTE_COMPRESSED 2048 0x800	A file or directory that is compressed. For a file, all of the data in the file is compressed. For a directory, compression is the default for newly created files and subdirectories. 壓縮文件
FILE_ATTRIBUTE_DEVICE 64 0x40	Reserved; do not use.
FILE_ATTRIBUTE_DIRECTORY 16 0x10	The handle that identifies a directory. 目錄文件
FILE_ATTRIBUTE_ENCRYPTED 16384 0x4000	A file or directory that is encrypted. For a file, all data streams in the file are encrypted. For a directory, encryption is the default for newly created files and subdirectories. 加密文件
FILE_ATTRIBUTE_HIDDEN 2 0x2	The file or directory is hidden. It is not included in an ordinary directory listing. 隱藏文件
FILE_ATTRIBUTE_NORMAL 128 0x80	A file or directory that does not have other attributes set. This attribute is valid only when used alone.
FILE_ATTRIBUTE_NOT_CONTENT_INDEXED 8192 0x2000	The file is not to be indexed by the content indexing service.
FILE_ATTRIBUTE_OFFLINE 4096 0x1000	The data of a file is not available immediately. This attribute indicates that the file data is physically moved to offline storage. This attribute is used by Remote Storage, which is the hierarchical storage management software. Applications should not arbitrarily change this attribute.
FILE_ATTRIBUTE_READONLY 1 0x1	A file or directory that is read-only. For a file, applications can read the file, but cannot write to it or delete it. For a directory, applications cannot delete it.
FILE_ATTRIBUTE_REPARSE_POINT 1024 0x400	A file or directory that has an associated reparse point, or a file that is a symbolic link.
FILE_ATTRIBUTE_SPARSE_FILE 512 0x200	A file that is a sparse file.
FILE_ATTRIBUTE_SYSTEM 4 0x4	A file or directory that the operating system uses a part of, or uses exclusively.
FILE_ATTRIBUTE_TEMPORARY 256 0x100	A file that is being used for temporary storage. File systems avoid writing data back to mass storage if sufficient cache memory is available, because typically, an application deletes a temporary file after the handle is closed. In that scenario, the system can entirely avoid writing the data. Otherwise, the data is written after the handle is closed.
FILE_ATTRIBUTE_VIRTUAL 65536 0x10000	A file is a virtual file.