[Android] How to Get ListWidget content is displayed in the list which ranges

Consult Great God , how can get to the content displayed ListWidget in which range in QListWidgetItems ;

example, now has 100 ListWidget Item, but now appears on the screen , only 10 , the other needs to show through the scrollbar .

How can we determine now displayed in the Item in QListWidgetItems which is located in the range ? such is 15-25 .

want to know how can determine this range ?
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reference to this function :
QModelIndex QAbstractItemView :: indexAt (const QPoint & point) const [pure virtual]
Returns the model index of the item at the viewport coordinates point.

viewport visible rect is able to achieve , and then calculate the uppermost and lowermost visible index is easy.

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for larger models , I suggest you use QListView and QstandardModel the modelView model . Instead ListWidget this type.
In addition to the first floor of a method , you can try the following function .
QScrollBar ::
void setMaximum (int)
void setMinimum (int)
void setPageStep (int)
idea is that you have many pictures , you set the maximum value is the number, and then set the Step number of pictures per row . Then the current value from the scrollBar read in about which the picture is displayed . Functions like : int sliderPosition () const
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did not quite understand , to say in detail under it ?
------ eference --------------------------------------- < br> can you give points eXPRESS, study a little, or not understood. .
------ eference --------------------------------------- < br> how to get QModelIndex this corresponds QListWidgetItems after the index
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final solution is : m_listwidget-> indexAt (m_listwidget-> viewport () -> contentsRect (). center ()). row ( ) ;

Thank you very much 1st and 5th floor of help. Thanks to you to provide ideas . thank you!