PyQt/QGraphicsView练习/ImageView.py
2018-03-24 00:03:05 +08:00

108 lines
3.5 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Created on 2018年3月23日
@author: Irony
@site: https://github.com/892768447
@email: 892768447@qq.com
@file: ImageView
@description: 图片查看
"""
from PyQt5.QtCore import QStandardPaths, Qt
from PyQt5.QtGui import QColor, QPainter, QPixmap
from PyQt5.QtOpenGL import QGLFormat
from PyQt5.QtWidgets import QGraphicsView, QGraphicsScene, QFileDialog, \
QGraphicsItem
__Author__ = 'By: Irony\nQQ: 892768447\nEmail: 892768447@qq.com'
__Copyright__ = 'Copyright (c) 2018 Irony'
__Version__ = 1.0
class GraphicsView(QGraphicsView):
# 背景区域颜色
backgroundColor = QColor(28, 31, 34)
def __init__(self, *args, **kwargs):
super(GraphicsView, self).__init__(*args, **kwargs)
self.resize(800, 600)
# 设置背景颜色
self.setBackgroundBrush(self.backgroundColor)
# 缓存背景
self.setCacheMode(self.CacheBackground)
# 设置拖拽样式
# self.setDragMode(self.ScrollHandDrag)
self.setRenderHints(
QPainter.Antialiasing | QPainter.TextAntialiasing | QPainter.SmoothPixmapTransform)
# opengl
if QGLFormat.hasOpenGL():
self.setRenderHint(QPainter.HighQualityAntialiasing)
# 尝试通过分析需要重绘的区域来找到最佳的更新模式
self.setViewportUpdateMode(self.SmartViewportUpdate)
self._scene = QGraphicsScene(-400, -300, 800, 600, self)
self.setScene(self._scene)
# 图片item
self._itemImage = None
def keyReleaseEvent(self, event):
"""按键处理事件"""
self._scaleImage(event)
super(GraphicsView, self).keyReleaseEvent(event)
def closeEvent(self, event):
"""窗口关闭时清空场景中的所有item"""
self._scene.clear()
self._itemImage = None
super(GraphicsView, self).closeEvent(event)
def _scaleImage(self, event):
"""缩放图片操作"""
if not self._itemImage:
return
scale = self._itemImage.scale()
if event.key() == Qt.Key_Plus:
# 放大
if scale >= 0.91:
return
self._itemImage.setScale(scale + 0.1)
elif event.key() == Qt.Key_Minus:
# 缩小
if scale <= 0.11:
return
self._itemImage.setScale(scale - 0.1)
def loadImage(self):
path, _ = QFileDialog.getOpenFileName(
self, '请选择图片', QStandardPaths.writableLocation(QStandardPaths.DesktopLocation), '图片文件(*.jpg *.png)')
if not path:
return
if self._itemImage:
# 删除以前的item
self._scene.removeItem(self._itemImage)
del self._itemImage
self._itemImage = self._scene.addPixmap(QPixmap(path))
self._itemImage.setFlag(QGraphicsItem.ItemIsMovable)
self._itemImage.setScale(0.1) # 默认加载比例
size = self._itemImage.pixmap().size()
# 调整图片在中间
self._itemImage.setPos(
-size.width() * self._itemImage.scale() / 2,
-size.height() * self._itemImage.scale() / 2
)
if __name__ == '__main__':
import sys
import os
print(os.getpid())
from PyQt5.QtWidgets import QApplication, QPushButton
app = QApplication(sys.argv)
w = GraphicsView()
w.show()
ww = QPushButton('选择文件', clicked=w.loadImage)
ww.show()
sys.exit(app.exec_())