qfileinfo.html

QT 下载资料仅供参考

<p>Example: <a href="fileiconview-example.html#x818">fileiconview/qfileiconview.cpp</a>.
<h3 class=fn>bool <a name="exists"></a>QFileInfo::exists () const
</h3>
Returns TRUE if the file exists; otherwise returns FALSE.

<p>Examples: <a href="biff-example.html#x1941">biff/biff.cpp</a> and <a href="i18n-example.html#x1926">i18n/main.cpp</a>.
<h3 class=fn><a href="qstring.html">QString</a> <a name="extension"></a>QFileInfo::extension ( bool&nbsp;complete = TRUE ) const
</h3>
Returns the file's extension name.
<p> If <em>complete</em> is TRUE (the default), <a href="#extension">extension</a>() returns the string
of all characters in the file name after (but not including) the
first '.'  character.
<p> If <em>complete</em> is FALSE, extension() returns the string of all
characters in the file name after (but not including) the last '.'
character.
<p> Example:
<pre>
     QFileInfo fi( "/tmp/archive.tar.gz" );
     <a href="qstring.html">QString</a> ext = fi.<a href="#extension">extension</a>();  // ext = "tar.gz"
     ext = fi.<a href="#extension">extension</a>( FALSE );   // ext = "gz"
  </pre>
 
<p> <p>See also <a href="#fileName">fileName</a>() and <a href="#baseName">baseName</a>().

<p> 
<p>Example: <a href="qdir-example.html#x1816">qdir/qdir.cpp</a>.
<h3 class=fn><a href="qstring.html">QString</a> <a name="fileName"></a>QFileInfo::fileName () const
</h3>
Returns the name of the file, the file path is not included.
<p> Example:
<pre>
     QFileInfo fi( "/tmp/archive.tar.gz" );
     <a href="qstring.html">QString</a> name = fi.<a href="#fileName">fileName</a>();              // name = "archive.tar.gz"
  </pre>
 
<p> <p>See also <a href="#isRelative">isRelative</a>(), <a href="#filePath">filePath</a>(), <a href="#baseName">baseName</a>() and <a href="#extension">extension</a>().

<p>Examples: <a href="dirview-example.html#x1715">dirview/dirview.cpp</a> and <a href="fileiconview-example.html#x819">fileiconview/qfileiconview.cpp</a>.
<h3 class=fn><a href="qstring.html">QString</a> <a name="filePath"></a>QFileInfo::filePath () const
</h3>
Returns the file name, including the path (which may be absolute or
relative).
<p> <p>See also <a href="#isRelative">isRelative</a>() and <a href="#absFilePath">absFilePath</a>().

<p>Examples: <a href="dirview-example.html#x1751">dirview/main.cpp</a> and <a href="fileiconview-example.html#x820">fileiconview/qfileiconview.cpp</a>.
<h3 class=fn><a href="qstring.html">QString</a> <a name="group"></a>QFileInfo::group () const
</h3>
Returns the group of the file. On Windows, on systems where files do
not have groups, or if an error occurs, a null string is returned. 
<p> This function can be time consuming under Unix (in the order of
milliseconds).
<p> <p>See also <a href="#groupId">groupId</a>(), <a href="#owner">owner</a>() and <a href="#ownerId">ownerId</a>().

<h3 class=fn>uint <a name="groupId"></a>QFileInfo::groupId () const
</h3>
Returns the id of the group the file belongs to.
<p> On Windows and on systems where files do not have groups this function
always returns (uint) -2.
<p> <p>See also <a href="#group">group</a>(), <a href="#owner">owner</a>() and <a href="#ownerId">ownerId</a>().

<h3 class=fn>bool <a name="isDir"></a>QFileInfo::isDir () const
</h3>
Returns TRUE if this object points to a directory or to a symbolic
link to a directory; otherwise returns FALSE.
<p>See also <a href="#isFile">isFile</a>() and <a href="#isSymLink">isSymLink</a>().

<p>Examples: <a href="dirview-example.html#x1716">dirview/dirview.cpp</a> and <a href="fileiconview-example.html#x821">fileiconview/qfileiconview.cpp</a>.
<h3 class=fn>bool <a name="isExecutable"></a>QFileInfo::isExecutable () const
</h3>
Returns TRUE if the file is executable; otherwise returns FALSE.
<p>See also <a href="#isReadable">isReadable</a>(), <a href="#isWritable">isWritable</a>() and <a href="#permission">permission</a>().

<h3 class=fn>bool <a name="isFile"></a>QFileInfo::isFile () const
</h3>
Returns TRUE if this object points to a file. Returns FALSE if the
object points to something which isn't a file, e.g. a directory or a
symlink.
<p> <p>See also <a href="#isDir">isDir</a>() and <a href="#isSymLink">isSymLink</a>().

<p>Examples: <a href="dirview-example.html#x1717">dirview/dirview.cpp</a>, <a href="fileiconview-example.html#x822">fileiconview/qfileiconview.cpp</a> and <a href="qdir-example.html#x1817">qdir/qdir.cpp</a>.
<h3 class=fn>bool <a name="isReadable"></a>QFileInfo::isReadable () const
</h3>
Returns TRUE if the file is readable; otherwise returns FALSE.
<p>See also <a href="#isWritable">isWritable</a>(), <a href="#isExecutable">isExecutable</a>() and <a href="#permission">permission</a>().

<h3 class=fn>bool <a name="isRelative"></a>QFileInfo::isRelative () const
</h3>
Returns TRUE if the file path name is relative. Returns FALSE if the
path is absolute (e.g. under Unix a path is absolute if it
begins with a "/").

<h3 class=fn>bool <a name="isSymLink"></a>QFileInfo::isSymLink () const
</h3>
Returns TRUE if this object points to a symbolic link (or to a
shortcut on Windows); otherwise returns FALSE. 
<p> <p>See also <a href="#isFile">isFile</a>(), <a href="#isDir">isDir</a>() and <a href="#readLink">readLink</a>().

<p>Examples: <a href="dirview-example.html#x1718">dirview/dirview.cpp</a> and <a href="fileiconview-example.html#x823">fileiconview/qfileiconview.cpp</a>.
<h3 class=fn>bool <a name="isWritable"></a>QFileInfo::isWritable () const
</h3>
Returns TRUE if the file is writable; otherwise returns FALSE.
<p>See also <a href="#isReadable">isReadable</a>(), <a href="#isExecutable">isExecutable</a>() and <a href="#permission">permission</a>().

<h3 class=fn><a href="qdatetime.html">QDateTime</a> <a name="lastModified"></a>QFileInfo::lastModified () const
</h3>
Returns the date and time when the file was last modified.
<p> <p>See also <a href="#created">created</a>() and <a href="#lastRead">lastRead</a>().

<p>Example: <a href="biff-example.html#x1942">biff/biff.cpp</a>.
<h3 class=fn><a href="qdatetime.html">QDateTime</a> <a name="lastRead"></a>QFileInfo::lastRead () const
</h3>
Returns the date and time when the file was last read (accessed).
<p> On platforms where this information is not available, returns the
same as <a href="#lastModified">lastModified</a>().
<p> <p>See also <a href="#created">created</a>() and <a href="#lastModified">lastModified</a>().

<p>Example: <a href="biff-example.html#x1943">biff/biff.cpp</a>.
<h3 class=fn><a href="qfileinfo.html">QFileInfo</a>&nbsp;&amp; <a name="operator-eq"></a>QFileInfo::operator= ( const&nbsp;<a href="qfileinfo.html">QFileInfo</a>&nbsp;&amp;&nbsp;fi )
</h3>
Makes a copy of <em>fi</em> and assigns it to this QFileInfo.

<h3 class=fn><a href="qstring.html">QString</a> <a name="owner"></a>QFileInfo::owner () const
</h3>
Returns the owner of the file. On Windows, on systems where files do
not have owners, or if an error occurs, a null string is returned. 
<p> This function can be time consuming under Unix (in the order of
milliseconds).
<p> <p>See also <a href="#ownerId">ownerId</a>(), <a href="#group">group</a>() and <a href="#groupId">groupId</a>().

<h3 class=fn>uint <a name="ownerId"></a>QFileInfo::ownerId () const
</h3>
Returns the id of the owner of the file.
<p> On Windows and on systems where files do not have owners this function
returns ((uint) -2).
<p> <p>See also <a href="#owner">owner</a>(), <a href="#group">group</a>() and <a href="#groupId">groupId</a>().

<h3 class=fn>bool <a name="permission"></a>QFileInfo::permission ( int&nbsp;permissionSpec ) const
</h3>

<p> Tests for file permissions.  The <em>permissionSpec</em> argument can be several
flags of type PermissionSpec OR-ed together to check for permission
combinations.
<p> On systems where files do not have permissions this function always
returns TRUE.
<p> Example:
<pre>
    QFileInfo fi( "/tmp/archive.tar.gz" );
    if ( fi.<a href="#permission">permission</a>( QFileInfo::<a href="#PermissionSpec-enum">WriteUser</a> | QFileInfo::<a href="#PermissionSpec-enum">ReadGroup</a> ) )
        <a href="qapplication.html#qWarning">qWarning</a>( "I can change the file; my group can read the file.");
    if ( fi.<a href="#permission">permission</a>( QFileInfo::<a href="#PermissionSpec-enum">WriteGroup</a> | QFileInfo::<a href="#PermissionSpec-enum">WriteOther</a> ) )
        <a href="qapplication.html#qWarning">qWarning</a>( "The group or others can change the file!" );
  </pre>
 
<p> <p>See also <a href="#isReadable">isReadable</a>(), <a href="#isWritable">isWritable</a>() and <a href="#isExecutable">isExecutable</a>().

<h3 class=fn><a href="qstring.html">QString</a> <a name="readLink"></a>QFileInfo::readLink () const
</h3>
Returns the name a symlink (or shortcut on Windows) points to, or a
null <a href="qstring.html">QString</a> if the object isn't a symbolic link.
<p> This name may not represent an existing file; it is only a string.
<a href="#exists">QFileInfo::exists</a>() returns TRUE if the symlink points to an
existing file.
<p> <p>See also <a href="#exists">exists</a>(), <a href="#isSymLink">isSymLink</a>(), <a href="#isDir">isDir</a>() and <a href="#isFile">isFile</a>().

<h3 class=fn>void <a name="refresh"></a>QFileInfo::refresh () const
</h3>
Refreshes the information about the file, i.e. reads in information
from the file system the next time a cached property is fetched.
<p> <p>See also <a href="#setCaching">setCaching</a>().

<h3 class=fn>void <a name="setCaching"></a>QFileInfo::setCaching ( bool&nbsp;enable )
</h3>
If <em>enable</em> is TRUE, enables caching of file information. If <em>enable</em> is FALSE caching is disabled.
<p> When caching is enabled, QFileInfo reads the file information from the
file system the first time it's needed, but generally not later.
<p> Caching is enabled by default.
<p> <p>See also <a href="#refresh">refresh</a>() and <a href="#caching">caching</a>().

<h3 class=fn>void <a name="setFile"></a>QFileInfo::setFile ( const&nbsp;<a href="qstring.html">QString</a>&nbsp;&amp;&nbsp;file )
</h3>
Sets the file that the QFileInfo provides information about to <em>file</em>.
<p> The string given can be an absolute or a relative file path. Absolute
paths begin with the directory separator (e.g. "/" under Unix) or a drive
specification (not applicable to Unix). Relative file names begin with a
directory name or a file name and specify a path relative to the current
directory.
<p> Example:
<pre>
    <a href="qstring.html">QString</a> absolute = "/local/bin";
    <a href="qstring.html">QString</a> relative = "local/bin";
    QFileInfo absFile( absolute );
    QFileInfo relFile( relative );

    QDir::<a href="qdir.html#setCurrent">setCurrent</a>( QDir::<a href="qdir.html#rootDirPath">rootDirPath</a>() );
    // absFile and relFile now point to the same file

    QDir::<a href="qdir.html#setCurrent">setCurrent</a>( "/tmp" );
    // absFile now points to "/local/bin",
    // while relFile points to "/tmp/local/bin"
  </pre>
 
<p> <p>See also <a href="#isRelative">isRelative</a>(), <a href="qdir.html#setCurrent">QDir::setCurrent</a>() and <a href="qdir.html#isRelativePath">QDir::isRelativePath</a>().

<p>Example: <a href="biff-example.html#x1944">biff/biff.cpp</a>.
<h3 class=fn>void <a name="setFile-2"></a>QFileInfo::setFile ( const&nbsp;<a href="qfile.html">QFile</a>&nbsp;&amp;&nbsp;file )
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Sets the file that the QFileInfo provides information about to <em>file</em>.
<p> If the file has a relative path, the QFileInfo will also have a
relative path.
<p> <p>See also <a href="#isRelative">isRelative</a>().

<h3 class=fn>void <a name="setFile-3"></a>QFileInfo::setFile ( const&nbsp;<a href="qdir.html">QDir</a>&nbsp;&amp;&nbsp;d, const&nbsp;<a href="qstring.html">QString</a>&nbsp;&amp;&nbsp;fileName )
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Sets the file that the QFileInfo provides information about to <em>fileName</em> in directory <em>d</em>.
<p> If the file has a relative path, the QFileInfo will also have a
relative path.
<p> <p>See also <a href="#isRelative">isRelative</a>().

<h3 class=fn>uint <a name="size"></a>QFileInfo::size () const
</h3>
Returns the file size in bytes, or 0 if the file does not exist or if
the size is 0 or if the size cannot be fetched.

<p>Example: <a href="qdir-example.html#x1818">qdir/qdir.cpp</a>.
<!-- eof -->
<hr><p>
This file is part of the <a href="index.html">Qt toolkit</a>.
Copyright &copy; 1995-2002
<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
<table width=100% cellspacing=0 border=0><tr>
<td>Copyright &copy; 2002 
<a href="http://www.trolltech.com">Trolltech</a><td><a href="http://www.trolltech.com/trademarks.html">Trademarks</a>
<td align=right><div align=right>Qt version 3.0.5</div>
</table></div></address></body>
</html>