QDataWidgetMapper ¶

概要 ¶

详细描述 ¶

QDataWidgetMapper can be used to create data-aware widgets by mapping them to sections of an item model. A section is a column of a model if the orientation is horizontal (the default), otherwise a row.

Every time the current index changes, each widget is updated with data from the model via the property specified when its mapping was made. If the user edits the contents of a widget, the changes are read using the same property and written back to the model. By default, each widget’s user 特性 is used to transfer data between the model and the widget. Since Qt 4.3, an additional addMapping() function enables a named property to be used instead of the default user property.

It is possible to set an item delegate to support custom widgets. By default, a QItemDelegate is used to synchronize the model with the widgets.

Let us assume that we have an item model named model with the following contents:

1	Qt Norway	Oslo
2	Qt Australia	Brisbane
3	Qt USA	Palo Alto
4	Qt China	Beijing
5	Qt Germany	Berlin

The following code will map the columns of the model to widgets called mySpinBox , myLineEdit and myCountryChooser :

mapper = QDataWidgetMapper
mapper.setModel(model)
mapper.addMapping(mySpinBox, 0)
mapper.addMapping(myLineEdit, 1)
mapper.addMapping(myCountryChooser, 2)
mapper.toFirst()
											

After the call to toFirst() , mySpinBox displays the value 1 , myLineEdit displays Qt Norway and myCountryChooser displays Oslo . The navigational functions toFirst() , toNext() , toPrevious() , toLast() and setCurrentIndex() can be used to navigate in the model and update the widgets with contents from the model.

setRootIndex() function enables a particular item in a model to be specified as the root index - children of this item will be mapped to the relevant widgets in the user interface.

QDataWidgetMapper supports two submit policies, AutoSubmit and ManualSubmit . AutoSubmit will update the model as soon as the current widget loses focus, ManualSubmit will not update the model unless submit() 被调用。 ManualSubmit is useful when displaying a dialog that lets the user cancel all modifications. Also, other views that display the model won’t update until the user finishes all their modifications and submits.

注意： QDataWidgetMapper keeps track of external modifications. If the contents of the model are updated in another module of the application, the widgets are updated as well.

另请参阅

QAbstractItemModel QAbstractItemDelegate

class QDataWidgetMapper ( [ parent=None ] ) ¶

param parent

QObject

构造新 QDataWidgetMapper with parent object parent . By default, the orientation is horizontal and the submit policy is AutoSubmit .

另请参阅

setOrientation() setSubmitPolicy()

PySide2.QtWidgets.QDataWidgetMapper. SubmitPolicy ¶

This enum describes the possible submit policies a QDataWidgetMapper 支持。

常量	描述
QDataWidgetMapper.AutoSubmit	Whenever a widget loses focus, the widget’s current value is set to the item model.
QDataWidgetMapper.ManualSubmit	The model is not updated until submit() 被调用。

PySide2.QtWidgets.QDataWidgetMapper. addMapping ( widget , section ) ¶

参数

• widget – QWidget

• section – int

Adds a mapping between a widget 和 section from the model. The section is a column in the model if the orientation is horizontal (the default), otherwise a row.

For the following example, we assume a model myModel that has two columns: the first one contains the names of people in a group, and the second column contains their ages. The first column is mapped to the QLineEdit nameLineEdit , and the second is mapped to the QSpinBox ageSpinBox :

mapper = QDataWidgetMapper()
mapper.setModel(myModel)
mapper.addMapping(nameLineEdit, 0)
mapper.addMapping(ageSpinBox, 1)
											

注意事项：

• 若 widget is already mapped to a section, the old mapping will be replaced by the new one.

• Only one-to-one mappings between sections and widgets are allowed. It is not possible to map a single section to multiple widgets, or to map a single widget to multiple sections.

另请参阅

removeMapping() mappedSection() clearMapping()

PySide2.QtWidgets.QDataWidgetMapper. addMapping ( widget , section , propertyName ) ¶

参数

• widget – QWidget

• section – int

• propertyName – QByteArray

Essentially the same as addMapping() , but adds the possibility to specify the property to use specifying propertyName .

另请参阅

addMapping()

PySide2.QtWidgets.QDataWidgetMapper. clearMapping ( ) ¶

Clears all mappings.

另请参阅

addMapping() removeMapping()

PySide2.QtWidgets.QDataWidgetMapper. currentIndex ( ) ¶

返回类型

int

另请参阅

setCurrentIndex()

PySide2.QtWidgets.QDataWidgetMapper. currentIndexChanged ( index ) ¶

参数

index – int

PySide2.QtWidgets.QDataWidgetMapper. itemDelegate ( ) ¶

返回类型

QAbstractItemDelegate

Returns the current item delegate.

另请参阅

setItemDelegate()

PySide2.QtWidgets.QDataWidgetMapper. mappedPropertyName ( widget ) ¶

参数

widget – QWidget

返回类型

QByteArray

Returns the name of the property that is used when mapping data to the given widget .

另请参阅

mappedSection() addMapping() removeMapping()

PySide2.QtWidgets.QDataWidgetMapper. mappedSection ( widget ) ¶

参数

widget – QWidget

返回类型

int

Returns the section the widget is mapped to or -1 if the widget is not mapped.

另请参阅

addMapping() removeMapping()

PySide2.QtWidgets.QDataWidgetMapper. mappedWidgetAt ( section ) ¶

参数

section – int

返回类型

QWidget

Returns the widget that is mapped at section , or 0 if no widget is mapped at that section.

另请参阅

addMapping() removeMapping()

PySide2.QtWidgets.QDataWidgetMapper. model ( ) ¶

返回类型

QAbstractItemModel

Returns the current model.

另请参阅

setModel()

PySide2.QtWidgets.QDataWidgetMapper. orientation ( ) ¶

返回类型

取向

另请参阅

setOrientation()

PySide2.QtWidgets.QDataWidgetMapper. removeMapping ( widget ) ¶

参数

widget – QWidget

Removes the mapping for the given widget .

另请参阅

addMapping() clearMapping()

PySide2.QtWidgets.QDataWidgetMapper. revert ( ) ¶

Repopulates all widgets with the current data of the model. All unsubmitted changes will be lost.

另请参阅

submit() setSubmitPolicy()

PySide2.QtWidgets.QDataWidgetMapper. rootIndex ( ) ¶

返回类型

QModelIndex

Returns the current root index.

另请参阅

setRootIndex()

PySide2.QtWidgets.QDataWidgetMapper. setCurrentIndex ( index ) ¶

参数

index – int

另请参阅

currentIndex()

PySide2.QtWidgets.QDataWidgetMapper. setCurrentModelIndex ( index ) ¶

参数

index – QModelIndex

Sets the current index to the row of the index if the orientation is horizontal (the default), otherwise to the column of the index .

调用 setCurrentIndex() internally. This convenience slot can be connected to the signal currentRowChanged() or currentColumnChanged() of another view’s selection model .

The following example illustrates how to update all widgets with new data whenever the selection of a QTableView named myTableView changes:

mapper = QDataWidgetMapper()
connect(myTableView.selectionModel(), SIGNAL("currentRowChanged(QModelIndex,QModelIndex)"),
        mapper, SLOT(setCurrentModelIndex(QModelIndex)))
											

另请参阅

currentIndex()

PySide2.QtWidgets.QDataWidgetMapper. setItemDelegate ( delegate ) ¶

参数

delegate – QAbstractItemDelegate

Sets the item delegate to delegate . The delegate will be used to write data from the model into the widget and from the widget to the model, using setEditorData() and setModelData() .

The delegate also decides when to apply data and when to change the editor, using commitData() and closeEditor() .

警告

You should not share the same instance of a delegate between widget mappers or views. Doing so can cause incorrect or unintuitive editing behavior since each view connected to a given delegate may receive the closeEditor() signal, and attempt to access, modify or close an editor that has already been closed.

另请参阅

itemDelegate()

PySide2.QtWidgets.QDataWidgetMapper. setModel ( model ) ¶

参数

model – QAbstractItemModel

Sets the current model to model . If another model was set, all mappings to that old model are cleared.

另请参阅

model()

PySide2.QtWidgets.QDataWidgetMapper. setOrientation ( aOrientation ) ¶

参数

aOrientation – 取向

另请参阅

orientation()

PySide2.QtWidgets.QDataWidgetMapper. setRootIndex ( index ) ¶

参数

index – QModelIndex

Sets the root item to index . This can be used to display a branch of a tree. Pass an invalid model index to display the top-most branch.

另请参阅

rootIndex()

PySide2.QtWidgets.QDataWidgetMapper. setSubmitPolicy ( policy ) ¶

参数

policy – SubmitPolicy

另请参阅

submitPolicy()

PySide2.QtWidgets.QDataWidgetMapper. submit ( ) ¶

返回类型

bool

Submits all changes from the mapped widgets to the model.

For every mapped section, the item delegate reads the current value from the widget and sets it in the model. Finally, the model’s submit() method is invoked.

返回 true if all the values were submitted, otherwise false.

Note: For database models, lastError() can be used to retrieve the last error.

另请参阅

revert() setSubmitPolicy()

PySide2.QtWidgets.QDataWidgetMapper. submitPolicy ( ) ¶

返回类型

SubmitPolicy

另请参阅

setSubmitPolicy()

PySide2.QtWidgets.QDataWidgetMapper. toFirst ( ) ¶

Populates the widgets with data from the first row of the model if the orientation is horizontal (the default), otherwise with data from the first column.

这相当于调用 setCurrentIndex(0) .

另请参阅

toLast() setCurrentIndex()

PySide2.QtWidgets.QDataWidgetMapper. toLast ( ) ¶

Populates the widgets with data from the last row of the model if the orientation is horizontal (the default), otherwise with data from the last column.

调用 setCurrentIndex() internally.

另请参阅

toFirst() setCurrentIndex()

PySide2.QtWidgets.QDataWidgetMapper. toNext ( ) ¶

Populates the widgets with data from the next row of the model if the orientation is horizontal (the default), otherwise with data from the next column.

调用 setCurrentIndex() internally. Does nothing if there is no next row in the model.

另请参阅

toPrevious() setCurrentIndex()

PySide2.QtWidgets.QDataWidgetMapper. toPrevious ( ) ¶

Populates the widgets with data from the previous row of the model if the orientation is horizontal (the default), otherwise with data from the previous column.

调用 setCurrentIndex() internally. Does nothing if there is no previous row in the model.

另请参阅

toNext() setCurrentIndex()