The information is only retrieved by views that can display header information.
In this section, we create a simple read-only model to explore the basic principles of the model/view architecture.
The separation of content and presentation is achieved by the use of a standard model interface provided by QAbstractItemModel, a standard view interface provided by QAbstractItemView, and the use of model indexes that represent items of data in a general way.To take advantage of QAbstractItemModel 's default implementation for the built-in mime type, new models must provide reimplementations of the following functions: insertRows These functions enable the model to automatically insert new data using the existing implementation provided.Exec An icon is shown in the upper left corner of the window.In this case, we only have a single top-level list of strings, so we just insert empty strings into that list.You can't invoke an external program directly from QML so we have to write it in C (which is the whole point of this example application).The signals and slots used by the model/view framework ensure that each view is updated appropriately no matter how many proxy models are placed between itself and the source model.However, note that the SpinBox we see is not properly located.When requesting an index for a model item, we must provide some information about the item's parent.QPushButton *quitBtn new QPushButton Quit this quitBtn- setGeometry(50, 40, 75, 30 We create a new QPushButton.H" #include QGridLayout PlusMinus:PlusMinus(QWidget *parent) : QWidget(parent) QPushButton *plsBtn new QPushButton this QPushButton *minBtn new QPushButton - this lbl new QLabel 0 this QGridLayout *grid new QGridLayout(this grid- addWidget(plsBtn, 0, 0 grid- addWidget(minBtn, 0, 1 grid- addWidget(lbl, 1, 1 setLayout(grid speltips holland casino reclame connect(plsBtn, signal(clicked this, slot(OnPlus connect(minBtn.The QTableView class provides a default model/view implementation of a table view.For example, if a model of two million rows needs to have all odd numbered rows removed, that is 1 million discountiguous ranges of 1 element each.We convert estimated import fees deposit nedir a number to the string texas holdem duk value.You can download the full source code for the example from here.This returns an unsorted list of model indexes that we can iterate over as long as we know which model they are for: QModelIndexList indexes QModelIndex index; foreach(index, indexes) QString text QString 1,2.arg(g(lumn model- setData(index, text The above code uses Qt's convenient foreach keyword.The problem that I'm having with C is that any error handling that's done has to be thought of before hand (think try/catch or massive conditionals).Typically, items contain data for a number of different roles, and the standard roles are defined by Qt:ItemDataRole.QTreeView displays items from a model as a hierarchy of lists, allowing deeply nested structures to be represented in a compact way.
Models that inherit from QAbstractListModel and QAbstractTableModel can take advantage of the default implementations of functions provided by those classes.