我已经有一个带有setText()的QTextEdit,但是我希望在用户选择“编辑文本”时清除占位符。此处显示的插图
最佳答案
placeholderText属性仅存在于Qt 5.2中,因此我为PyQt4实现了相同的逻辑:
from PyQt4 import QtCore, QtGui
class TextEdit(QtGui.QTextEdit):
@property
def placeholderText(self):
if not hasattr(self, "_placeholderText"):
self._placeholderText = ""
return self._placeholderText
@placeholderText.setter
def placeholderText(self, text):
self._placeholderText = text
self.update()
def isPreediting(self):
lay = self.textCursor().block().layout()
if lay and lay.preeditAreaText():
return True
return False
def paintEvent(self, event):
super(TextEdit, self).paintEvent(event)
if (
self.placeholderText
and self.document().isEmpty()
and not self.isPreediting()
):
painter = QtGui.QPainter(self.viewport())
col = self.palette().text().color()
col.setAlpha(128)
painter.setPen(col)
margin = int(self.document().documentMargin())
painter.drawText(
self.viewport().rect().adjusted(margin, margin, -margin, -margin),
QtCore.Qt.AlignTop | QtCore.Qt.TextWordWrap,
self.placeholderText,
)
if __name__ == "__main__":
import sys
app = QtGui.QApplication(sys.argv)
te = TextEdit()
te.placeholderText = "Stack Overflow"
w = QtGui.QWidget()
lay = QtGui.QVBoxLayout(w)
lay.addWidget(QtGui.QLineEdit())
lay.addWidget(te)
w.show()
sys.exit(app.exec_())
关于python - 如何在QTextEdit中插入和清除占位符,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/56966714/