VC判断一个文件为目录的方法
本文实例讲述了VC判断一个文件为目录的方法,分享给大家供大家参考。具体实现方法如下:
这是一个自定义函数,用于判断一个文件是否为目录:
/**
* 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); //得到文件属性
if (dwAttr == 0xFFFFFFFF) // 文件或目录不存在
return false;
else if (dwAttr&FILE_ATTRIBUTE_DIRECTORY) // 如果是目录
return true;
else
return false;
}
以下是GetFileAttribute定义,摘自msdn:
Retrieves a set of FAT file system attributes for a specified file or directory.得到FAT文件系统的文件属性
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 "//?/" to the path. For more information, see Naming a File.文件名或目录名。最大长度为系统的文件名最大长度。如果是unicode环境,需要调用这个函数的unicode版本。
Return Value
If the function succeeds, the return value contains the attributes of the specified file or directory.
如果函数成功了,返回值会包含以下文件属性:
If the function fails, the return value is INVALID_FILE_ATTRIBUTES. To get extended error information, call GetLastError.
如果函数失败,返回值是INVALID_FILE_ATTRIBUTES. 可以通过GetLastError获取更详细的出错信息
The attributes can be one or more of the following values.
文件属性可以是下列值的一个或多个的组合。
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. 存档文件 |
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. 压缩文件 |
FILE_ATTRIBUTE_DEVICE 64 0x40 |
Reserved; do not use. |
FILE_ATTRIBUTE_DIRECTORY 16 0x10 |
The handle that identifies a directory. 目录文件 |
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. 隐藏文件 |
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. |
希望本文所述对大家的VC程序设计有所帮助。