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Duracell
Asked:2022-08-21 02:21:13 +0800 CST2022-08-21 02:21:13 +0800 CST

QLineGradient 平滑颜色之间的边界

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任务是绘制item's第一列中的所有内容，但不仅仅是用一种颜色，而是 40% 的宽度应该用一种颜色填充，另外 60% 用另一种颜色填充，而且还不是很大的条件，边界之间颜色应均匀，无模糊，混色效果。我尝试这样：QTreeWidgetbackgrounditem'a

self.treeWidget = QTreeWidget()
self.treeWidget.setColumnCount(3)
self.treeWidget.setHeaderLabels(['1', '2', '3'])
self.treeWidget.addTopLevelItem(QTreeWidgetItem(['item1', 'item2', 'item3']))
grad = QLinearGradient(QPointF(0, 0),QPointF(self.treeWidget.columnWidth(0), 0))                                            
grad.setStops([(0.4, QColor(255, 0, 0)),(0.41, QColor(0, 255, 0)),])
grad.setCoordinateMode(QLinearGradient.CoordinateMode.ObjectBoundingMode)
self.treeWidget.topLevelItem(0).setBackground(0, grad)

事实证明是胡说八道，如何做对呢？也许使用另一种方法会更好？哪个？

python python-3.x

2 个回答

  1. 渐变将设置渐变:) 这里需要稍微复杂一点。自己画背景，重载QTreeWidget::drawRow

    from PyQt5.QtWidgets import *
from PyQt5.QtGui import QBrush, QColor
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QGridLayout, QWidget
from PyQt5.QtCore import QSize, QRect

# Нам нужен свой "кастомный" виджет, в котором перегрузим отрисовку строки 
class MyTreeWidget(QTreeWidget):
    def drawRow(self, painter, option, index):   # Перегружаем отрисовку строки
        if index.column() == 0:   # фон меняем только для первого столбца
            rect = self.visualRect(index)   # узнаем геометрическое расположение ячейки
            corner = rect.width() * 0.6   # вычисляем ширину по которой будут разделяться цвета
            rect1 = QRect(rect.left(), rect.top(), corner, rect.height())   # прямоугольник для первого цвета
            rect2 = QRect(rect.left() + corner, rect.top(), rect.width() - corner, rect.height())   # то же самое для второго
            # отрисовываем фон
            painter.save()
            brush = QBrush(QColor(255, 0, 0))
            painter.fillRect(rect1, brush)
            brush = QBrush(QColor(0, 255, 0))
            painter.fillRect(rect2, brush)
            painter.restore()
        super(QTreeWidget, self).drawRow(painter, option, index)   # дальнейшей отрисовкой занимается оригинальный QTreeWidget::drawRow


class MainWindow(QMainWindow):

    def __init__(self):
        QMainWindow.__init__(self)
        self.setMinimumSize(QSize(400, 400))
        central_widget = QWidget(self)
        self.setCentralWidget(central_widget)
        grid_layout = QGridLayout()
        self.treeWidget = MyTreeWidget()
        self.treeWidget.setColumnCount(3)
        self.treeWidget.setHeaderLabels(['1', '2', '3'])
        self.treeWidget.addTopLevelItem(QTreeWidgetItem(['myitem11', 'item12', 'item13']))
        self.treeWidget.addTopLevelItem(QTreeWidgetItem(['item21', 'item22', 'item23']))
        central_widget.setLayout(grid_layout)
        grid_layout.addWidget(self.treeWidget, 0, 0)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    mw = MainWindow()
    mw.show()
    sys.exit(app.exec())

    应该马上指出，您当然可以使用通常的背景来绘制背景QTrwwWidgetItem::setBackground(column, brush)，但是这样的背景不会以任何方式改变单元格的大小

    • 1
  2. Best Answer

    它位于计算梯度宽度的坐标空间中，只需将其转换为逻辑模式：

    grad = QLinearGradient(QPointF(0, 0), QPointF(self.treeWidget.columnWidth(2), 0))
stop1 = round(itemListSell[i]['total'] / maxSellOrder, 2)
stop2 = stop1 + 0.01
grad.setStops([(stop1, QColor(255, 0, 0)),(stop2, QColor(0, 255, 0)),])                               grad.setCoordinateMode(QLinearGradient.CoordinateMode.LogicalMode)

    现在QLinearGradient.CoordinateMode.LogicalMode，从列宽获取坐标，以实际大小，而不是 (x1: 0, x2: 0 y1: 1, y2: 1) 是的，为了使渐变边界清晰均匀，没有模糊 -您需要使用颜色过渡之间的最小边界，我将它们放在变量中stop1并且stop2

    • 0

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