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QIntDictIterator Class

发布于 2019-10-04 15:00:51 字数 4223 浏览 1006 评论 0 收藏 0

The QIntDictIterator class provides an iterator for QIntDict collections. More...

#include <qintdict.h>

List of all member functions.

Public Members

  • QIntDictIterator ( constQIntDict<type>&dict )
  • ~QIntDictIterator ()
  • uint count () const
  • bool isEmpty () const
  • type * toFirst ()
  • operator type * () const
  • type * current () const
  • long currentKey () const
  • type * operator() ()
  • type * operator++ ()
  • type * operator+= ( uintjump )

Detailed Description

The QIntDictIterator class provides an iterator for QIntDict collections.

QIntDictIterator is implemented as a template class. Define a template instance QIntDictIterator<X> to create a dictionary iterator that operates on QIntDict<X> (dictionary of X*).

Example:

    QIntDict<QLineEdit> fields;
    for ( int i = 0; i < 3; i++ )
        fields.insert( i, new QLineEdit( this ) );

    fields[0]->setText( "Homer" );
    fields[1]->setText( "Simpson" );
    fields[2]->setText( "45" );

    QIntDictIterator<char> it( fields ); 
    for ( ; it.current(); ++it )
        cout << it.currentKey() << ": " << it.current()->text() << endl;

    // Output (random order):
    //  0: Homer
    //  1: Simpson
    //  2: 45
  

Note that the traversal order is arbitrary; you are not guaranteed the order above.

Multiple iterators may independently traverse the same dictionary. A QIntDict knows about all the iterators that are operating on the dictionary. When an item is removed from the dictionary, QIntDict updates all iterators that refer the removed item to point to the next item in the traversing order.

See also QIntDict, Collection Classes and Non-GUI Classes.


Member Function Documentation

QIntDictIterator::QIntDictIterator ( constQIntDict<type>&dict )

Constructs an iterator for dict. The current iterator item is set to point to the 'first' item in the dict. The first item refers to the first item in the dictionary's arbitrary internal ordering.

QIntDictIterator::~QIntDictIterator ()

Destroys the iterator.

uint QIntDictIterator::count () const

Returns the number of items in the dictionary this iterator operates over.

See also isEmpty().

type * QIntDictIterator::current () const

Returns a pointer to the current iterator item.

long QIntDictIterator::currentKey () const

Returns the key for the current iterator item.

bool QIntDictIterator::isEmpty () const

Returns TRUE if the dictionary is empty; otherwise eturns FALSE.

See also count().

QIntDictIterator::operator type * () const

Cast operator. Returns a pointer to the current iterator item. Same as current().

type * QIntDictIterator::operator() ()

Makes the succeeding item current and returns the original current item.

If the current iterator item was the last item in the dictionary or if it was null, null is returned.

type * QIntDictIterator::operator++ ()

Prefix ++ makes the succeeding item current and returns the new current item.

If the current iterator item was the last item in the dictionary or if it was null, null is returned.

type * QIntDictIterator::operator+= ( uintjump )

Sets the current item to the item jump positions after the current item, and returns a pointer to that item.

If that item is beyond the last item or if the dictionary is empty, it sets the current item to null and returns null.

type * QIntDictIterator::toFirst ()

Sets the current iterator item to point to the first item in the dictionary and returns a pointer to the item. The first item refers to the first item in the dictionary's arbitrary internal ordering. If the dictionary is empty it sets the current item to null and returns null.

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