QTemporaryFile Class

      // Within a function/method...

      QTemporaryFile file;
      if (file.open()) {
          // file.fileName() returns the unique file name
      }

      // The QTemporaryFile destructor removes the temporary file
      // as it goes out of scope.

成员函数

QTemporaryFile::QTemporaryFile()

Constructs a QTemporaryFile using as file template the application name returned by QCoreApplication::applicationName() (otherwise qt_temp) followed by ".XXXXXX". The file is stored in the system's temporary directory, QDir::tempPath().

参见 setFileTemplate() and QDir::tempPath().

QTemporaryFile::QTemporaryFile(const QString &templateName)

Constructs a QTemporaryFile with a template filename of templateName. Upon opening the temporary file this will be used to create a unique filename.

If the templateName does not contain XXXXXX it will automatically be appended and used as the dynamic portion of the filename.

If templateName is a relative path, the path will be relative to the current working directory. You can use QDir::tempPath() to construct templateName if you want use the system's temporary directory.

参见 open() and fileTemplate().

QTemporaryFile::QTemporaryFile(QObject *parent)

Constructs a QTemporaryFile (with the given parent) using as file template the application name returned by QCoreApplication::applicationName() (otherwise qt_temp) followed by ".XXXXXX". The file is stored in the system's temporary directory, QDir::tempPath().

参见 setFileTemplate().

QTemporaryFile::QTemporaryFile(const QString &templateName, QObject *parent)

Constructs a QTemporaryFile with a template filename of templateName and the specified parent. Upon opening the temporary file this will be used to create a unique filename.

If the templateName does not contain XXXXXX it will automatically be appended and used as the dynamic portion of the filename.

If templateName is a relative path, the path will be relative to the current working directory. You can use QDir::tempPath() to construct templateName if you want use the system's temporary directory.

参见 open() and fileTemplate().

QTemporaryFile::~QTemporaryFile()

Destroys the temporary file object, the file is automatically closed if necessary and if in auto remove mode it will automatically delete the file.

参见 autoRemove().

bool QTemporaryFile::autoRemove() const

Returns true if the QTemporaryFile is in auto remove mode. Auto-remove mode will automatically delete the filename from disk upon destruction. This makes it very easy to create your QTemporaryFile object on the stack, fill it with data, read from it, and finally on function return it will automatically clean up after itself.

Auto-remove is on by default.

参见 setAutoRemove() and remove().

[static] QTemporaryFile *QTemporaryFile::createNativeFile(QFile &file)

If file is not already a native file, then a QTemporaryFile is created in QDir::tempPath(), the contents of file is copied into it, and a pointer to the temporary file is returned. Does nothing and returns 0 if file is already a native file.

For example:

  QFile f(":/resources/file.txt");
  QTemporaryFile::createNativeFile(f); // Returns a pointer to a temporary file

  QFile f("/users/qt/file.txt");
  QTemporaryFile::createNativeFile(f); // Returns 0

参见 QFileInfo::isNativePath().

[static] QTemporaryFile *QTemporaryFile::createNativeFile(const QString &fileName)

This is an overloaded function.

Works on the given fileName rather than an existing QFile object.

[virtual] QString QTemporaryFile::fileName() const

Reimplemented from QFileDevice::fileName().

Returns the complete unique filename backing the QTemporaryFile object. This string is null before the QTemporaryFile is opened, afterwards it will contain the fileTemplate() plus additional characters to make it unique.

参见 fileTemplate().

QString QTemporaryFile::fileTemplate() const

Returns the set file template. The default file template will be called qcoreappname.XXXXXX and be placed in QDir::tempPath().

参见 setFileTemplate().

bool QTemporaryFile::open()

A QTemporaryFile will always be opened in QIODevice::ReadWrite mode, this allows easy access to the data in the file. This function will return true upon success and will set the fileName() to the unique filename used.

参见 fileName().

[virtual protected] bool QTemporaryFile::open(OpenMode flags)

Reimplemented from QIODevice::open().

Creates a unique file name for the temporary file, and opens it. You can get the unique name later by calling fileName(). The file is guaranteed to have been created by this function (i.e., it has never existed before).

void QTemporaryFile::setAutoRemove(bool b)

Sets the QTemporaryFile into auto-remove mode if b is true.

Auto-remove is on by default.

参见 autoRemove() and remove().

void QTemporaryFile::setFileTemplate(const QString &name)

Sets the static portion of the file name to name. If the file template contains XXXXXX that will automatically be replaced with the unique part of the filename, otherwise a filename will be determined automatically based on the static portion specified.

If name contains a relative file path, the path will be relative to the current working directory. You can use QDir::tempPath() to construct name if you want use the system's temporary directory.

参见 fileTemplate().