Change the method of Qtreeview (change the height of the delegate line, or: When the data is:d ATA, judge by Qt::sizehintrole)

A long time ago wrote an article about Qtreeview fast display more than thousands data items, if that article is about Qtreeview's internal strength, today this is about qtreeview drilling, sometimes we want to change the view of the row height of the data item, how to do? Here are two ways to change the line height here today:

1. By changing the default delegate method for Qtreeview

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2. Class Cdelegate: Public qstyleditemdelegate
4. {
6. Q_object
8. Public
10. Cdelegate (Qobject *parent): qstyleditemdelegate (parent)
12. {
16. }
18. Protected
20. Qsize sizehint (const Qstyleoptionviewitem &option,
22. Const Qmodelindex &index) Const
24. {
26. Qsize size = qstyleditemdelegate::sizehint (option, index);
28. return Qsize (Size.width (), 28);
30. }
32. };

By default, Qtreeview uses Qstyleditemdelegate as its proxy, by overloading the Qstyleditemdelegate Sizehint method, I set the row height here to 28, you can modify the corresponding row height as needed, and then, By replacing the default proxy with Qtreeview with cdelegate, I do the following:

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1. Ctreeview::ctreeview (Qwidget *parent): Qtreeview (parent)
2. {
3. Cdelegate *pdelegate = new Cdelegate (this);
4. Setitemdelegate (pdelegate);
5. Setuniformrowheights (true);
6. }

Is it easy for everyone to see?

2. Use the data method of the overloaded Qabstractitemmodel as follows:

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2. Qvariant Cmchmodel::d ata (const qmodelindex &index, int role) const
4. {
6. if (!index.isvalid ())
8. return qvariant ();
10. if (qt::sizehintrole = = role)
12. {
14. return Qsize (Ptreeview->visualrect (index). Width (), 28);
16. }
18. return qvariant ();
20. }

Where Ptreeview is the CTreeView above, the method does not add in the CTreeView constructor:

[CPP]View PlainCopy

1. Cdelegate *pdelegate = new Cdelegate (this);
2. Setitemdelegate (pdelegate);

is not also very simple.

http://blog.csdn.net/rabinsong/article/details/13161799

Change the method of Qtreeview (change the height of the delegate line, or: When the data is:d ATA, judge by Qt::sizehintrole)