Comunicarea cu utilizatorul¶

Showing messages. The QgsMessageBar class.¶

Using mesages boxes can be a bad idea from a user experience point of view. For showing a small info line or a warning/error messages, the QGIS message bar is usually a better option

Using the reference to the QGIS interface object, you can show a message in the message bar with the following code.

iface.messageBar().pushMessage("Error", "I'm sorry Dave, I'm afraid I can't \
  do that", level=QgsMessageBar.CRITICAL)

Bara de mesaje a QGIS

You can set a duration to show it for a limited time.

iface.messageBar().pushMessage("Error", ""Ooops, the plugin is not working as \
  it should", level=QgsMessageBar.CRITICAL, duration=3)

Bara de mesaje a QGIS, cu cronometru

The examples above show an error bar, but the level parameter can be used to creating warning messages or info messages, using the QgsMessageBar.WARNING and QgsMessageBar.INFO constants repectively.

QGIS Message bar (warning)

Bara de mesaje a QGIS (info)

Widget-urile pot fi adăugate la bara de mesaje, cum ar fi, de exemplu, un buton pentru afișarea mai multor informații

def showError():
pass

widget = iface.messageBar().createMessage("Missing Layers", "Show Me")
button = QPushButton(widget)
button.setText("Show Me")
button.pressed.connect(showError)
widget.layout().addWidget(button)
iface.messageBar().pushWidget(widget, QgsMessageBar.WARNING)

Bara de mesaje a QGIS, cu un buton

You can even use a message bar in your own dialog so you don’t have to show a message box, or if it doesn’t make sense to show it in the main QGIS window.

class MyDialog(QDialog):
    def __init__(self):
        QDialog.__init__(self)
        self.bar = QgsMessageBar()
        self.bar.setSizePolicy( QSizePolicy.Minimum, QSizePolicy.Fixed )
        self.setLayout(QGridLayout())
        self.layout().setContentsMargins(0,0,0,0)
        self.buttonbox = QDialogButtonBox(QDialogButtonBox.Ok)
        self.buttonbox.accepted.connect(self.run)
        self.layout().addWidget(self.buttonbox , 0,0,2,1)
        self.layout().addWidget(self.bar, 0,0,1,1)

    def run(self):
        self.bar.pushMessage("Hello", "World", level=QgsMessageBar.INFO)

Bara de mesaje a QGIS, într-o fereastră de dialog

Afișarea progresului¶

Barele de progres pot fi, de asemenea, incluse în bara de mesaje QGIS, din moment ce, așa cum am văzut, aceasta acceptă widget-uri. Iată un exemplu pe care îl puteți încerca în consolă.

import time
from PyQt4.QtGui import QProgressBar
from PyQt4.QtCore import *
progressMessageBar = iface.messageBar().createMessage("Doing something boring...")
progress = QProgressBar()
progress.setMaximum(10)
progress.setAlignment(Qt.AlignLeft|Qt.AlignVCenter)
progressMessageBar.layout().addWidget(progress)
iface.messageBar().pushWidget(progressMessageBar, iface.messageBar().INFO)
for i in range(10):
        time.sleep(1)
        progress.setValue(i + 1)
iface.messageBar().clearWidgets()

Also, you can use the built-in status bar to report progress, as in the next example.

::

count = layers.featureCount() for i, feature in enumerate(features):

#do something time-consuming here ... percent = i / float(count) * 100 iface.mainWindow().statusBar().showMessage(“Processed {} %”.format(int(percent)))

iface.mainWindow().statusBar().clearMessage()

Jurnalizare¶

Puteți utiliza sistemul de jurnalizare al QGIS, pentru a salva toate informațiile pe care doriți să le înregistrați, cu privire la execuția codului dvs.

QgsMessageLog.logMessage("Your plugin code has been executed correctly", \
  QgsMessageLog.INFO)
QgsMessageLog.logMessage("Your plugin code might have some problems", \
  QgsMessageLog.WARNING)
QgsMessageLog.logMessage("Your plugin code has crashed!", \
  QgsMessageLog.CRITICAL)