简而言之，我的树表可以使用浮点数，并且我想限制表中显示的小数位数，但是我不想丢失数据，因为我使用它来进行计算。我继承了ItemDelegate的子类，并覆盖了paint方法，以便可以在单元格中绘制更少的小数点而不会实际丢失数据。下面的代码是其中的代码，主要焦点在try块的最后一行。
def paint(self, painter, option, index):
value = index.model().data(index, QtCore.Qt.EditRole)
item = self.treeWidget.itemFromIndex(index)
col = index.column()
try:
if col == 0:
QtWidgets.QItemDelegate.paint(self, painter, option, index)
else:
if isinstance(item, AssignmentType):
painter.setPen(QtCore.Qt.darkGreen)
painter.setFont(typeFont)
elif isinstance(item, Assignment):
painter.setPen(QtCore.Qt.blue)
painter.setFont(assFont)
else:
painter.setPen(QtCore.Qt.darkBlue)
painter.setFont(courseFont)
text = value if "/" in value else "{:.{}f}".format(float(value)*100, self.nDecimals)
painter.drawText(option.rect, QtCore.Qt.AlignCenter, text)
except:
QtWidgets.QItemDelegate.paint(self, painter, option, index)
此方法的副作用是，受painter.drawText(option.rect, QtCore.Qt.AlignCenter, text)代码行影响的单元格在单击时不会突出显示。我试图在我的绘画方法中有条件地更改树小部件的调色板，但这似乎无济于事。我以为连接itemClicked信号会有所帮助，但我不知道该在那做什么。 python或c中的任何想法/代码将不胜感激。完整的代码和该项目的示例.grdb文件如下：
import json
from PyQt5 import QtCore, QtGui, QtWidgets
courseFont = QtGui.QFont()
courseFont.setBold(True)
courseFont.setWeight(100)
courseFont.setPointSize(18)
typeFont = QtGui.QFont()
typeFont.setUnderline(True)
typeFont.setPointSize(16)
typeFont.setWeight(50)
assFont = QtGui.QFont()
assFont.setItalic(True)
assFont.setPointSize(14)
assFont.setWeight(50)
extraCreditFont = QtGui.QFont()
extraCreditFont.setItalic(True)
extraCreditFont.setUnderline(True)
extraCreditFont.setPointSize(14)
extraCreditFont.setWeight(75)
class KeyPressedTree(QtWidgets.QTreeWidget):
keyPressed = QtCore.pyqtSignal(int)
def keyPressEvent(self, event):
super(KeyPressedTree, self).keyPressEvent(event)
self.keyPressed.emit(event.key())
class Course(QtWidgets.QTreeWidgetItem):
def __init__(self, parent, data=["New Course", "", ""], *__args):
super().__init__(parent, data)
self.setFont(0, courseFont)
self.setFlags(
QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEditable | QtCore.Qt.ItemIsDragEnabled | QtCore.Qt.ItemIsUserCheckable | QtCore.Qt.ItemIsEnabled)
class AssignmentType(QtWidgets.QTreeWidgetItem):
def __init__(self, parent, data=["New Assignment Type", "", ""], *__args):
super().__init__(parent, data)
self.setFont(0, typeFont)
self.setFlags(
QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEditable | QtCore.Qt.ItemIsDragEnabled | QtCore.Qt.ItemIsUserCheckable | QtCore.Qt.ItemIsEnabled)
self.extraCredit = False
def setExtraCredit(self,isExtra):
self.extraCredit = isExtra
def isExtraCredit(self):
return self.extraCredit
class Assignment(QtWidgets.QTreeWidgetItem):
def __init__(self, parent, data=["New Assignment", "", ""], *__args):
super().__init__(parent, data)
self.setFont(0, assFont)
self.extraCredit = False
self.setFlags(
QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEditable | QtCore.Qt.ItemIsDragEnabled | QtCore.Qt.ItemIsUserCheckable | QtCore.Qt.ItemIsEnabled)
def setExtraCredit(self,isExtra):
self.extraCredit = isExtra
def isExtraCredit(self):
return self.extraCredit
class ValidWeightGradeInput(QtWidgets.QItemDelegate):
def createEditor(self, parent, option, index):
line = QtWidgets.QLineEdit(parent)
reg_ex = QtCore.QRegExp(r"|0?\.\d+|\d*\.?\d+/\d*\.?\d+")
input_validator = QtGui.QRegExpValidator(reg_ex, line)
line.setValidator(input_validator)
return line
class FloatDelegate(QtWidgets.QItemDelegate):
def __init__(self, decimals, parent: KeyPressedTree):
self.treeWidget = parent
QtWidgets.QItemDelegate.__init__(self, parent=parent)
self.nDecimals = decimals
def createEditor(self, parent, option, index):
# if any of the below conditions are met, then the cell is editable.
# basically, if the first index is zero, then it's editable
# if the weight column for the assignment type item is selected, then it's editable
# if the grade column for the assignment item is selected, it's editable
# in all other cases, it's not editable.
if index.column() == 0:
return QtWidgets.QItemDelegate.createEditor(self, parent, option, index)
elif (
index.column() == 1 and isinstance(self.treeWidget.itemFromIndex(index), AssignmentType)) or (
index.column() == 2 and isinstance(self.treeWidget.itemFromIndex(index), Assignment)):
return ValidWeightGradeInput.createEditor(self, parent, option, index)
else:
return None
def paint(self, painter, option, index):
value = index.model().data(index, QtCore.Qt.EditRole)
item = self.treeWidget.itemFromIndex(index)
col = index.column()
try:
if col == 0:
QtWidgets.QItemDelegate.paint(self, painter, option, index)
else:
if isinstance(item, AssignmentType):
painter.setPen(QtCore.Qt.darkGreen)
painter.setFont(typeFont)
elif isinstance(item, Assignment):
painter.setPen(QtCore.Qt.blue)
painter.setFont(assFont)
else:
painter.setPen(QtCore.Qt.darkBlue)
painter.setFont(courseFont)
text = value if "/" in value else "{:.{}f}".format(float(value)*100, self.nDecimals)
painter.drawText(option.rect, QtCore.Qt.AlignCenter, text)
except:
QtWidgets.QItemDelegate.paint(self, painter, option, index)
class Ui_MainWindow(QtWidgets.QMainWindow):
def setupUi(self):
self.setWindowTitle("Grade Manager")
self.resize(620, 600)
self.centralwidget = QtWidgets.QWidget(self)
self.verticalLayout = QtWidgets.QVBoxLayout(self.centralwidget)
self.treeWidget = KeyPressedTree(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
sizePolicy.setHeightForWidth(self.treeWidget.sizePolicy().hasHeightForWidth())
self.treeWidget.setSizePolicy(sizePolicy)
self.treeWidget.setMinimumSize(QtCore.QSize(620, 600))
font = QtGui.QFont()
font.setPointSize(20)
font.setWeight(100)
self.treeWidget.setFont(font)
self.treeWidget.setAlternatingRowColors(True)
self.treeWidget.setSelectionBehavior(QtWidgets.QAbstractItemView.SelectItems)
self.treeWidget.setAnimated(True)
self.treeWidget.setWordWrap(True)
self.treeWidget.headerItem().setText(0, "Course")
self.treeWidget.headerItem().setText(1, "Weight")
self.treeWidget.headerItem().setText(2, "Grade")
self.treeWidget.headerItem().setTextAlignment(0, QtCore.Qt.AlignCenter)
self.treeWidget.headerItem().setTextAlignment(1, QtCore.Qt.AlignCenter)
self.treeWidget.headerItem().setTextAlignment(2, QtCore.Qt.AlignCenter)
self.treeWidget.setColumnWidth(0,370)
self.treeWidget.setColumnWidth(1,130)
self.treeWidget.setColumnWidth(2,100)
# self.treeWidget.header().setDefaultSectionSize(275)
# self.treeWidget.header().setMinimumSectionSize(50)
self.treeWidget.header().setStretchLastSection(True)
self.verticalLayout.addWidget(self.treeWidget)
self.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(self)
self.menubar.setGeometry(QtCore.QRect(0, 0, 912, 35))
self.menuFile = QtWidgets.QMenu(self.menubar)
self.menuFile.setTitle("Fi&le")
self.setMenuBar(self.menubar)
self.actionOpen = QtWidgets.QAction(self, text="&Open")
self.actionOpen.setShortcut("Ctrl+O")
self.actionClose = QtWidgets.QAction(self, text="&Close")
self.actionNew = QtWidgets.QAction(self, text="&New")
self.actionSave = QtWidgets.QAction(self, text="&Save")
self.actionSave.setShortcut("Ctrl+S")
self.actionSave_as = QtWidgets.QAction(self, text="Sa&ve as...")
self.actionSave_as.setShortcut("Ctrl+Shift+S")
self.menuFile.addAction(self.actionNew)
self.menuFile.addAction(self.actionOpen)
self.menuFile.addAction(self.actionClose)
self.menuFile.addSeparator()
self.menuFile.addAction(self.actionSave)
self.menuFile.addAction(self.actionSave_as)
self.menubar.addAction(self.menuFile.menuAction())
self.courses = []
self.treeWidget.setItemDelegate(FloatDelegate(2, self.treeWidget))
self.treeWidget.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
self.treeWidget.customContextMenuRequested.connect(self.openMenu)
self.actionSave.triggered.connect(self.saveJSON)
self.actionOpen.triggered.connect(self.readJSON)
self.actionSave_as.triggered.connect(self.saveAsJSON)
self.actionNew.triggered.connect(self.clearPage)
self.actionClose.triggered.connect(self.close)
self.treeWidget.itemChanged.connect(self.itemClicked)
self.treeWidget.keyPressed.connect(self.keyPressed)
self.filename = None
self.change_made = False
def clearPage(self):
if self.change_made:
answer = QtWidgets.QMessageBox.question(self, "Close Confirmation",
"Would you like to save before exiting?",
QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No | QtWidgets.QMessageBox.Cancel)
if answer == QtWidgets.QMessageBox.Cancel:
return
elif answer == QtWidgets.QMessageBox.Yes:
self.saveJSON()
self.treeWidget.clear()
self.courses = []
self.filename = None
self.change_made = False
def addCourse(self):
course = Course(self.treeWidget)
course.setExpanded(True)
self.courses.append(course)
self.change_made = True
def addType(self, course):
t = AssignmentType(course)
t.setExpanded(True)
course.addChild(t)
self.change_made = True
def addAssignment(self, assignment_type):
ass = Assignment(assignment_type)
assignment_type.addChild(ass)
self.change_made = True
def removeItem(self, item, level):
root = self.treeWidget.invisibleRootItem()
parent = item.parent()
(parent or root).removeChild(item)
if level == 2: # if just the assignment was removed
self.updateTypeGrade(parent)
elif level == 1: # if the assignment type was just removed
self.updateCourseGrade(parent)
self.change_made = True
def openMenu(self, position):
menu = QtWidgets.QMenu(self)
indices = self.treeWidget.selectedItems()
level = 0
if not indices:
menu.addAction(self.tr("Add New Course"))
else:
i = indices[0]
while i.parent():
i = i.parent()
level += 1
choices = (("Add New Course", "Add New Assignment Type", "Remove Selected Course"),
("Add New Assignment", "Remove Selected Assignment Type"), ("Remove Assignment",
"Set As Not Extra Credit" if level == 2 and indices[0].isExtraCredit() else "Set As Extra Credit"))
[menu.addAction(self.tr(act)) for act in choices[level]]
action = menu.exec_(self.treeWidget.viewport().mapToGlobal(position))
if action:
action = action.text()
if action == "Add New Course":
self.addCourse()
elif action == "Add New Assignment Type":
self.addType(indices[0])
elif action == "Add New Assignment":
self.addAssignment(indices[0])
elif action == "Set As Extra Credit":
indices[0].setExtraCredit(True)
self.updateTypeGrade(indices[0].parent())
indices[0].setFont(0,extraCreditFont)
self.change_made = True
elif action == "Set As Not Extra Credit":
indices[0].setExtraCredit(False)
self.updateTypeGrade(indices[0].parent())
indices[0].setFont(0,assFont)
self.change_made = True
else:
self.removeItem(indices[0], level)
def saveJSON(self):
self.filename = self.save(self.filename)
def saveAsJSON(self):
self.save()
def transformInput(self, data: str):
if "/" in data:
i = data.find("/")
return float(data[:i]) / float(data[i + 1:])
return float(data)
def updateTypeGrade(self, ass_type):
type_grade = 0.0
num_assignments = ass_type.childCount()
for i in range(num_assignments):
grade = ass_type.child(i).text(2)
if not grade: # if the column is empty
num_assignments -= 1
continue
if ass_type.child(i).isExtraCredit():
num_assignments -= 1
type_grade += self.transformInput(grade)
type_grade = f"{type_grade / num_assignments}" if num_assignments > 0 else ""
ass_type.setText(2, type_grade)
def updateCourseGrade(self, course):
total_weight = 0.0
earned_weight = 0.0
for i in range(course.childCount()):
t = course.child(i)
weight = t.text(1)
grade = t.text(2)
if not weight or not grade: # if no weight is entered
continue
total_weight += self.transformInput(weight)
earned_weight += self.transformInput(weight) * self.transformInput(grade)
course_grade = str(earned_weight / total_weight) if total_weight > 0 else ""
course.setText(2, course_grade)
def itemClicked(self, item, col):
self.change_made = True
if isinstance(item, Course) or col == 0:
return
elif isinstance(item, Assignment):
item = item.parent() # changes assignment to the assignment type
self.updateTypeGrade(item)
# from this point, the item must be an assignment type.
self.updateCourseGrade(item.parent())
def keyPressed(self, key):
indices = self.treeWidget.selectedItems()
level = 0
if not indices: # if no tree item is selected
if key == QtCore.Qt.Key_Insert:
self.addCourse()
else:
i = indices[0]
while i.parent():
i = i.parent()
level += 1
i = indices[0]
if key == QtCore.Qt.Key_Delete:
self.removeItem(i, level)
else:
if level == 0:
if key == QtCore.Qt.Key_Insert:
self.addType(i)
elif level == 1:
if key == QtCore.Qt.Key_Insert:
self.addAssignment(i)
elif level == 2:
pass
def save(self, filename=None):
if not filename: # if a file hasn't been opened yet (save as or new file)
filename, _ = QtWidgets.QFileDialog.getSaveFileName(self, "Save File", "./",
"Gradebook Files (*.grdb)")
if filename:
data = {"Course": []}
for course in self.courses:
c_data = {"Name": course.text(0), "Weight": course.text(1), "Grade": course.text(2),
"Expanded": course.isExpanded(), "Types": []}
for i in range(course.childCount()):
t = course.child(i)
t_data = {"Name": t.text(0), "Weight": t.text(1), "Grade": t.text(2), "Expanded": t.isExpanded(),
"Assignments": []}
for j in range(t.childCount()):
ass = t.child(j)
t_data["Assignments"].append({"Name": ass.text(0), "Weight": ass.text(1), "Grade": ass.text(2), "Extra Credit": ass.isExtraCredit()})
c_data["Types"].append(t_data)
data["Course"].append(c_data)
with open(filename.replace(".grdb", "") + ".grdb", "w+") as f:
json.dump(data, f)
self.change_made = True
return filename
def readJSON(self):
filename, _ = QtWidgets.QFileDialog.getOpenFileName(self, "Select File", "",
"Gradebook Files (*.grdb)")
if filename:
with open(filename) as json_file:
self.clearPage()
self.filename = filename
data = json.load(json_file)
for course_dict in data["Course"]:
course = Course(self.treeWidget, [course_dict["Name"], course_dict["Weight"], course_dict["Grade"]])
course.setExpanded(course_dict["Expanded"])
for type_dict in course_dict["Types"]:
t = AssignmentType(course, [type_dict["Name"], type_dict["Weight"], type_dict["Grade"]])
t.setExpanded(type_dict["Expanded"])
for assignment in type_dict["Assignments"]:
ass = Assignment(t, [assignment["Name"], assignment["Weight"], assignment["Grade"]])
if assignment["Extra Credit"]:
ass.setExtraCredit(True)
ass.setFont(0,extraCreditFont)
t.addChild(ass)
course.addChild(t)
self.courses.append(course)
self.change_made = False
def closeEvent(self, event):
if self.change_made:
event.ignore()
answer = QtWidgets.QMessageBox.question(self, "Close Confirmation",
"Would you like to save before exiting?",
QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No | QtWidgets.QMessageBox.Cancel)
if answer == QtWidgets.QMessageBox.Cancel:
return
elif answer == QtWidgets.QMessageBox.Yes:
self.saveJSON()
event.accept()
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
ui = Ui_MainWindow()
ui.setupUi()
ui.show()
sys.exit(app.exec_())
{"Course": [{"Name": "A Course", "Weight": "", "Grade": "0.9099999999999999", "Expanded": true, "Types": [{"Name": "Exams", "Weight": ".7", "Grade": "0.925", "Expanded": true, "Assignments": [{"Name": "Exam 1", "Weight": "", "Grade": "95/100", "Extra Credit": false}, {"Name": "Exam 2", "Weight": "", "Grade": ".9", "Extra Credit": false}]}, {"Name": "Quizzes", "Weight": "3/10", "Grade": "0.875", "Expanded": true, "Assignments": [{"Name": "Quiz 1", "Weight": "", "Grade": "8/10", "Extra Credit": false}, {"Name": "Quiz 2", "Weight": "", "Grade": ".95", "Extra Credit": false}, {"Name": "Quiz 3", "Weight": "", "Grade": "", "Extra Credit": false}]}]}]}
答案 0 :(得分：1)
与其对QPainter进行直接绘画，不如只对QStyleOptionViewItem进行修改，并且应通过覆盖drawDisplay方法来完成部分文本更改。
class FloatDelegate(QtWidgets.QItemDelegate):
def __init__(self, decimals, parent: KeyPressedTree):
self.treeWidget = parent
Qsuper(FloatDelegate, self).__init__(parent=parent)
self.nDecimals = decimals
def createEditor(self, parent, option, index):
# ...
def paint(self, painter, option, index):
item = self.treeWidget.itemFromIndex(index)
if index.column() != 0:
font = courseFont
color = QtCore.Qt.darkBlue
if isinstance(item, AssignmentType):
color = QtCore.Qt.darkGreen
font = typeFont
elif isinstance(item, Assignment):
color = QtCore.Qt.blue
font = assFont
cg = QtGui.QPalette.Normal if option.state & QtWidgets.QStyle.State_Enabled else QtGui.QPalette.Disabled
option.palette.setColor(cg, QtGui.QPalette.Text, color)
option.font = font
super(FloatDelegate, self).paint(painter, option, index)
def drawDisplay(self, painter, option, rect, text):
if "/" not in text:
try:
text = "{:.{}f}".format(float(text)*100, self.nDecimals)
except ValueError:
pass
super(FloatDelegate, self).drawDisplay(painter, option, rect, text)