我正在用pyqt5编写一个程序，并希望通过使用sqlite来存储输入来创建QlineEdit显示历史输入。当focusInEvent发生时我使用一个信号来捕捉光标并选择那时的历史记录，然后我把结果放到QCompleter中，这样它就可以在QlineEdit中弹出。现在我可以在QlineEdit对象中显示历史输入，但是当我点击任何值时，1秒后，整个程序会自动退出并显示错误，其中显示“Python已停止”。
class FocusLineEdit(QLineEdit):
ac = pyqtSignal(list)
def __init__(self, parent=None):
super(FocusLineEdit, self).__init__(parent)
self.ac.connect(self.addCompleter)
def focusInEvent(self, event):
rtl = call_history(self.objectName())
self.ac.emit(rtl)
def addCompleter(self, rtl):
self.autoCompleter = QCompleter(rtl)
self.autoCompleter.setCompletionMode(1)
self.setCompleter(self.autoCompleter)
def focusOutEvent(self, event):
pass
如果没有提供MCVE，很难分析问题所在，因此我的响应会实现您的需求，而不考虑您当前的代码，因为它必须满足以下要求：
在我的示例中，我使用以下说明创建它们：
CREATE TABLE IF NOT EXISTS objects (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL UNIQUE);
CREATE TABLE IF NOT EXISTS history (id INTEGER PRIMARY KEY AUTOINCREMENT, id_object INTEGER REFERENCES objects (id), word TEXT NOT NULL, UNIQUE (id_object, word));
另外为了测试它我创建了一个数据，如果你已经有数据，那么你必须消除if test:和里面的一切。
最后为了更好地理解我的解决方案，我展示了一个根据选择而改变的QTableView。
from PyQt5 import QtCore, QtGui, QtWidgets, QtSql
def createConnection():
db = QtSql.QSqlDatabase.addDatabase('QSQLITE')
db_path = 'test.db'
db.setDatabaseName(db_path)
if not db.open():
QMessageBox.critical(None, qApp.tr("Cannot open database"),
qApp.tr("Unable to establish a database connection.\n"
"This example needs SQLite support. Please read "
"the Qt SQL driver documentation for information "
"how to build it.\n\n"
"Click Cancel to exit."),
QMessageBox.Cancel)
return False
test = True
if test:
query = QtSql.QSqlQuery()
if not query.exec_('CREATE TABLE IF NOT EXISTS objects (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL UNIQUE);'):
return False
if not query.exec_('CREATE TABLE IF NOT EXISTS history (id INTEGER PRIMARY KEY AUTOINCREMENT, id_object INTEGER REFERENCES objects (id), word TEXT NOT NULL, UNIQUE (id_object, word));'):
return False
for i in range(3):
query.prepare('INSERT INTO objects (name) VALUES (?)')
query.addBindValue("obj{}".format(i))
if not query.exec_():
print(query.lastError().text())
import requests
import random
word_site = "http://svnweb.freebsd.org/csrg/share/dict/words?view=co&content-type=text/plain"
response = requests.get(word_site)
WORDS = response.content.decode().splitlines()
print(WORDS)
for i in range(3):
for text in random.sample(WORDS, 50):
query.prepare('INSERT INTO history (id_object, word) VALUES (?, ?)')
query.addBindValue(i+1)
query.addBindValue(text)
if not query.exec_():
print(query.lastError().text())
return True
class Completer(QtWidgets.QCompleter):
def __init__(self, parent=None):
super(Completer, self).__init__(parent)
self._last_words = []
def splitPath(self, path):
if path[-1] != ' ':
words = path.split()
self._last_words = words[:-1] if len(words) > 1 else []
return [words[-1]]
else:
QtCore.QTimer.singleShot(0, self.popup().hide)
return []
def pathFromIndex(self, index):
val = super(Completer, self).pathFromIndex(index)
return ' '.join(self._last_words + [val])
class HistoryManager(QtCore.QObject):
nameChanged = QtCore.pyqtSignal(str)
def __init__(self, parent=None):
super(HistoryManager, self).__init__(parent)
model = QtSql.QSqlRelationalTableModel(self)
model.setTable("history")
model.setRelation(1, QtSql.QSqlRelation("objects", "id", "name"))
model.select()
self._proxy = QtCore.QSortFilterProxyModel(self)
self._proxy.setSourceModel(model)
self._proxy.setFilterKeyColumn(1)
# proxy.setFilterFixedString("obj1")
self._widgets = {}
self._completer = Completer(self)
self._completer.setModel(self._proxy)
self._completer.setCompletionColumn(2)
def register_widget(self, widget, objectname):
# TODO
if callable(getattr(widget, "setCompleter")):
widget.installEventFilter(self)
self._widgets[widget] = objectname
return True
return False
def eventFilter(self, obj, event):
if obj in self._widgets:
if event.type() == QtCore.QEvent.FocusIn:
name = self._widgets[obj]
self._proxy.setFilterFixedString(name)
obj.setCompleter(self._completer)
self.nameChanged.emit(name)
elif event.type() == QtCore.QEvent.FocusOut:
obj.setCompleter(None)
self._proxy.setFilterFixedString("")
self.nameChanged.emit("")
return super(HistoryManager, self).eventFilter(obj, event)
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
self._manager = HistoryManager()
model = QtSql.QSqlRelationalTableModel(self)
model.setTable("history")
model.setRelation(1, QtSql.QSqlRelation("objects", "id", "name"))
model.select()
self._proxy = QtCore.QSortFilterProxyModel(self)
self._proxy.setSourceModel(model)
self._proxy.setFilterKeyColumn(1)
tv = QtWidgets.QTableView()
tv.setModel(self._proxy)
vlay = QtWidgets.QVBoxLayout()
for i in range(3):
le = QtWidgets.QLineEdit()
vlay.addWidget(le)
self._manager.register_widget(le, "obj{}".format(i))
vlay.addStretch()
lay = QtWidgets.QHBoxLayout(self)
lay.addWidget(tv, stretch=1)
lay.addLayout(vlay)
self._manager.nameChanged.connect(self._proxy.setFilterFixedString)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
if not createConnection():
sys.exit(-1)
manager = HistoryManager()
w = Widget()
w.resize(640, 480)
w.show()
sys.exit(app.exec_())