python GUI框架pyqt5 对图片进行流式布局的方法（瀑布流flowlayout）

流式布局

流式布局，也叫做瀑布流布局，是网页中经常使用的一种页面布局方式，它的原理就是将高度固定，然后图片的宽度自适应，这样加载出来的图片看起来就像瀑布一样整齐的水流淌下来。

pyqt流式布局

那么在pyqt5中我们怎么使用流式布局呢？pyqt没有这个控件，需要我们自己去封装，下面是流式布局的封装代码。

class FlowLayout(QLayout):
 def __init__(self, parent=None, margin=0, spacing=-1):
  super(FlowLayout, self).__init__(parent)

  if parent is not None:
   self.setContentsMargins(margin, margin, margin, margin)

  self.setSpacing(spacing)

  self.itemList = []

 def __del__(self):
  item = self.takeAt(0)
  while item:
   item = self.takeAt(0)

 def addItem(self, item):
  self.itemList.append(item)

 def count(self):
  return len(self.itemList)

 def itemAt(self, index):
  if index >= 0 and index < len(self.itemList):
   return self.itemList[index]

  return None

 def takeAt(self, index):
  if index >= 0 and index < len(self.itemList):
   return self.itemList.pop(index)

  return None

 def expandingDirections(self):
  return Qt.Orientations(Qt.Orientation(0))

 def hasHeightForWidth(self):
  return True

 def heightForWidth(self, width):
  height = self.doLayout(QRect(0, 0, width, 0), True)
  return height

 def setGeometry(self, rect):
  super(FlowLayout, self).setGeometry(rect)
  self.doLayout(rect, False)

 def sizeHint(self):
  return self.minimumSize()

 def minimumSize(self):
  size = QSize()

  for item in self.itemList:
   size = size.expandedTo(item.minimumSize())

  margin, _, _, _ = self.getContentsMargins()

  size += QSize(2 * margin, 2 * margin)
  return size

 def doLayout(self, rect, testOnly):
  x = rect.x()
  y = rect.y()
  lineHeight = 0

  for item in self.itemList:
   wid = item.widget()
   spaceX = self.spacing() + wid.style().layoutSpacing(QSizePolicy.PushButton,
                QSizePolicy.PushButton, Qt.Horizontal)
   spaceY = self.spacing() + wid.style().layoutSpacing(QSizePolicy.PushButton,
                QSizePolicy.PushButton, Qt.Vertical)
   nextX = x + item.sizeHint().width() + spaceX
   if nextX - spaceX > rect.right() and lineHeight > 0:
    x = rect.x()
    y = y + lineHeight + spaceY
    nextX = x + item.sizeHint().width() + spaceX
    lineHeight = 0

   if not testOnly:
    item.setGeometry(QRect(QPoint(x, y), item.sizeHint()))

   x = nextX
   lineHeight = max(lineHeight, item.sizeHint().height())

  return y + lineHeight - rect.y()

封装好的流式布局类，我们只要传入相应的layout之后，他就会自动计算页面的元素，适应页面的宽度。

下面是我们写的一个瀑布流显示图片的代码:

from PyQt5.QtCore import QPoint, QRect, QSize, Qt
import os
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import (
  QApplication, QLayout, QPushButton, QSizePolicy, QWidget, QGridLayout)

class Window(QWidget):
  def __init__(self):
    self.imageheight = 100
    super(Window, self).__init__()
    self.resize(400, 300)

    flowLayout = FlowLayout()

    highlight_dir = "./"
    self.files_it = iter([os.path.join(highlight_dir, file)
               for file in os.listdir(highlight_dir)])

    print()
    for file in iter(self.files_it):
      layout = QGridLayout()
      pixmap = QtGui.QPixmap(file)
      if not pixmap.isNull():
        autoWidth = pixmap.width()*self.imageheight/pixmap.height()
        label = QtWidgets.QLabel(pixmap=pixmap)
        label.setScaledContents(True)
        label.setFixedHeight(self.imageheight)
        print(autoWidth)
        label.setFixedWidth(autoWidth)
        #label.setFixedSize(100, 50)
        layout.addWidget(label)

        widget = QWidget()
        widget.setLayout(layout)
        flowLayout.addWidget(widget)

    self.setLayout(flowLayout)

    self.setWindowTitle("Flow Layout")

class FlowLayout(QLayout):
  def __init__(self, parent=None, margin=0, spacing=-1):
    super(FlowLayout, self).__init__(parent)

    if parent is not None:
      self.setContentsMargins(margin, margin, margin, margin)

    self.setSpacing(spacing)

    self.itemList = []

  def __del__(self):
    item = self.takeAt(0)
    while item:
      item = self.takeAt(0)

  def addItem(self, item):
    self.itemList.append(item)

  def count(self):
    return len(self.itemList)

  def itemAt(self, index):
    if index >= 0 and index < len(self.itemList):
      return self.itemList[index]

    return None

  def takeAt(self, index):
    if index >= 0 and index < len(self.itemList):
      return self.itemList.pop(index)

    return None

  def expandingDirections(self):
    return Qt.Orientations(Qt.Orientation(0))

  def hasHeightForWidth(self):
    return True

  def heightForWidth(self, width):
    height = self.doLayout(QRect(0, 0, width, 0), True)
    return height

  def setGeometry(self, rect):
    super(FlowLayout, self).setGeometry(rect)
    self.doLayout(rect, False)

  def sizeHint(self):
    return self.minimumSize()

  def minimumSize(self):
    size = QSize()

    for item in self.itemList:
      size = size.expandedTo(item.minimumSize())

    margin, _, _, _ = self.getContentsMargins()

    size += QSize(2 * margin, 2 * margin)
    return size

  def doLayout(self, rect, testOnly):
    x = rect.x()
    y = rect.y()
    lineHeight = 0

    for item in self.itemList:
      wid = item.widget()
      spaceX = self.spacing() + wid.style().layoutSpacing(QSizePolicy.PushButton,
                                QSizePolicy.PushButton, Qt.Horizontal)
      spaceY = self.spacing() + wid.style().layoutSpacing(QSizePolicy.PushButton,
                                QSizePolicy.PushButton, Qt.Vertical)
      nextX = x + item.sizeHint().width() + spaceX
      if nextX - spaceX > rect.right() and lineHeight > 0:
        x = rect.x()
        y = y + lineHeight + spaceY
        nextX = x + item.sizeHint().width() + spaceX
        lineHeight = 0

      if not testOnly:
        item.setGeometry(QRect(QPoint(x, y), item.sizeHint()))

      x = nextX
      lineHeight = max(lineHeight, item.sizeHint().height())

    return y + lineHeight - rect.y()

if __name__ == '__main__':

  import sys

  app = QApplication(sys.argv)
  mainWin = Window()
  mainWin.show()
  sys.exit(app.exec_())

到此这篇关于python GUI框架pyqt5 对图片进行流式布局的方法（瀑布流flowlayout）的文章就介绍到这了,更多相关python pyqt5图片流式布局内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！