Question

QWidget* EditDelegate::createEditor(
  QWidget* parent,
  const QStyleOptionViewItem& option,
  const QModelIndex& index) const
{
  QLineEdit* editor = NULL;
  if(index.isValid())
  {
    editor->resize(50,1000);  //this can not work in win7
  }
  return editor;
}

EditDelegate is subclass of QItemDelegate
what do you guys think this question?

Answer 1

after you declare QLineEdit pointer you need to create an instance of the class

if(index->isValid()) {
  editor = new QLineEdit();
  editor->resize(50, 1000);
}