qdict.3qt

linux下GUI编程工具qt的在线连接帮助手册

            styleAccel = "&" + styleAccel;
.br
            letterDict.insert(styleAccel.left(1), (const int *)1);
.br
        }
.br
        (void) new QAction( styleName, QIconSet(), styleAccel, parent );
.br
    }
.br
.fi
In the example we are using the dictionary to provide fast random access to the keys, and we don't care what the values are. The example is used to generate a menu of QStyles, each with a unique accelerator key (or no accelerator if there are no unused letters left).
.PP
We first obtain the list of available styles, then sort them so that the menu items will be ordered alphabetically. Next we create a dictionary of int pointers. The keys in the dictionary are each one character long, representing letters that have been used for accelerators. We iterate through our list of style names. If the first letter of the style name is in the dictionary, i.e. has been used, we iterate over all the characters in the style name to see if we can find a letter that hasn't been used. If we find an unused letter we put the accelerator ampersand (&) in front of it and add that letter to the dictionary. If we can't find an unused letter the style will simply have no accelerator. If the first letter of the style name is not in the dictionary we use it for the accelerator and add it to the dictionary. Finally we create a QAction for each style.
.PP
See also QDictIterator, QAsciiDict, QIntDict, QPtrDict, Collection Classes and Non-GUI Classes.
.SH MEMBER FUNCTION DOCUMENTATION
.SH "QDict::QDict ( int size = 17, bool caseSensitive = TRUE )"
Constructs a dictionary optimized for less than \fIsize\fR entries.
.PP
We recommend setting \fIsize\fR to a suitably large prime number (e.g. a prime that's slightly larger than the expected number of entries). This makes the hash distribution better which will lead to faster lookup.
.PP
If \fIcaseSensitive\fR is TRUE (the default), keys which differ only in case are considered different.
.SH "QDict::QDict ( const QDict<type> & dict )"
Constructs a copy of \fIdict\fR.
.PP
Each item in \fIdict\fR is inserted into this dictionary. Only the pointers are copied (shallow copy).
.SH "QDict::~QDict ()"
Removes all items from the dictionary and destroys it. If setAutoDelete() is TRUE each value is deleted. All iterators that access this dictionary will be reset.
.PP
See also setAutoDelete().
.SH "bool QPtrCollection::autoDelete () const"
Returns the setting of the auto-delete option. The default is FALSE.
.PP
See also setAutoDelete().
.SH "void QDict::clear ()\fC [virtual]\fR"
Removes all items from the dictionary.
.PP
The removed items are deleted if auto-deletion is enabled.
.PP
All dictionary iterators that operate on the dictionary are reset.
.PP
See also remove(), take() and setAutoDelete().
.PP
Reimplemented from QPtrCollection.
.SH "uint QDict::count () const\fC [virtual]\fR"
Returns the number of items in the dictionary.
.PP
See also isEmpty().
.PP
Reimplemented from QPtrCollection.
.SH "type * QDict::find ( const QString & key ) const"
Returns the item with key \fIkey\fR, or null if the key does not exist in the dictionary.
.PP
If there are two or more items with equal keys, then the last item that was inserted will be found.
.PP
Equivalent to the [] operator.
.PP
See also operator[]().
.SH "void QDict::insert ( const QString & key, const type * item )"
Inserts the key \fIkey\fR with value \fIitem\fR into the dictionary.
.PP
The key does not have to be unique. If multiple items are inserted with the same key, only the last item will be visible.
.PP
Null items are not allowed.
.PP
See also replace().
.SH "bool QDict::isEmpty () const"
Returns TRUE if the dictionary is empty, i.e. count() == 0; otherwise returns FALSE.
.PP
See also count().
.SH "QDict<type> & QDict::operator= ( const QDict<type> & dict )"
Assigns \fIdict\fR to this dictionary and returns a reference to this dictionary.
.PP
This dictionary is first cleared, then each item in \fIdict\fR is inserted into this dictionary. Only the pointers are copied (shallow copy), unless newItem() has been reimplemented().
.SH "type * QDict::operator[] ( const QString & key ) const"
Returns the item with key \fIkey\fR, or null if the key does not exist in the dictionary.
.PP
If there are two or more items with equal keys, then the last item that was inserted will be found.
.PP
Equivalent to the find() function.
.PP
See also find().
.SH "QDataStream & QDict::read ( QDataStream & s, QPtrCollection::Item & item )\fC [virtual protected]\fR"
Reads a dictionary item from the stream \fIs\fR and returns a reference to the stream.
.PP
The default implementation sets \fIitem\fR to 0.
.PP
See also write().
.SH "bool QDict::remove ( const QString & key )"
Removes the item with \fIkey\fR from the dictionary. Returns TRUE if successful, or FALSE if the key does not exist in the dictionary.
.PP
If there are two or more items with equal keys, then the last item that was inserted will be removed.
.PP
The removed item is deleted if auto-deletion is enabled.
.PP
All dictionary iterators that refer to the removed item will be set to point to the next item in the dictionary traversing order.
.PP
See also take(), clear() and setAutoDelete().
.SH "void QDict::replace ( const QString & key, const type * item )"
Replaces the value of the key, \fIkey\fR with \fIitem\fR.
.PP
If the item does not already exist, it will be inserted.
.PP
Null items are not allowed.
.PP
Equivalent to:
.PP
.nf
.br
    QDict<char> dict;
.br
        ...
.br
    if ( dict.find( key ) )
.br
        dict.remove( key );
.br
    dict.insert( key, item );
.br
.fi
.PP
If there are two or more items with equal keys, then the last item that was inserted will be replaced.
.PP
See also insert().
.SH "void QDict::resize ( uint newsize )"
Changes the size of the hashtable the \fInewsize\fR. The contents of the dictionary are preserved, but all iterators on the dictionary become invalid.
.SH "void QPtrCollection::setAutoDelete ( bool enable )"
Sets the collection to auto-delete its contents if \fIenable\fR is TRUE and to never delete them if \fIenable\fR is FALSE.
.PP
If auto-deleting is turned on, all the items in a collection are deleted when the collection itself is deleted. This is convenient if the collection has the only pointer to the items.
.PP
The default setting is FALSE, for safety. If you turn it on, be careful about copying the collection - you might find yourself with two collections deleting the same items.
.PP
Note that the auto-delete setting may also affect other functions in subclasses. For example, a subclass that has a remove() function will remove the item from its data structure, and if auto-delete is enabled, will also delete the item.
.PP
See also autoDelete().
.PP
Examples:
.)l grapher/grapher.cpp, scribble/scribble.cpp and table/bigtable/main.cpp.
.SH "uint QDict::size () const"
Returns the size of the internal hash array (as specified in the constructor).
.PP
See also count().
.SH "void QDict::statistics () const"
Debugging-only function that prints out the dictionary distribution using qDebug().
.SH "type * QDict::take ( const QString & key )"
Takes the item with \fIkey\fR out of the dictionary without deleting it (even if auto-deletion is enabled).
.PP
If there are two or more items with equal keys, then the last item that was inserted will be taken.
.PP
Returns a pointer to the item taken out, or null if the key does not exist in the dictionary.
.PP
All dictionary iterators that refer to the taken item will be set to point to the next item in the dictionary traversal order.
.PP
See also remove(), clear() and setAutoDelete().
.SH "QDataStream & QDict::write ( QDataStream & s, QPtrCollection::Item ) const\fC [virtual protected]\fR"
Writes a dictionary item to the stream \fIs\fR and returns a reference to the stream.
.PP
See also read().

.SH "SEE ALSO"
.BR http://doc.trolltech.com/qdict.html
.BR http://www.trolltech.com/faq/tech.html
.SH COPYRIGHT
Copyright 1992-2001 Trolltech AS, http://www.trolltech.com.  See the
license file included in the distribution for a complete license
statement.
.SH AUTHOR
Generated automatically from the source code.
.SH BUGS
If you find a bug in Qt, please report it as described in
.BR http://doc.trolltech.com/bughowto.html .
Good bug reports help us to help you. Thank you.
.P
The definitive Qt documentation is provided in HTML format; it is
located at $QTDIR/doc/html and can be read using Qt Assistant or with
a web browser. This man page is provided as a convenience for those
users who prefer man pages, although this format is not officially
supported by Trolltech. 
.P
If you find errors in this manual page, please report them to
.BR [e-mail] .
Please include the name of the manual page (qdict.3qt) and the Qt
version (3.0.0).