Python 如何在pyqt5上使用QPixmap实现图片缩放

我试图放大我用QPixmap实现的图片，但没有任何效果。下面是我实现这一点的方法。（self.auteur是表示高度的浮点数）

我已经把我的标签放到一个布局中，以便把它放到一个滚动小部件中

self.layout6.addWidget(self.label)

如果我想建立一种方法，通过按下按钮放大或缩小窗口中的图片，我该怎么做？我试图调整标签的大小，但没有效果

self.action5=QAction(QIcon("Icon/in"),"Zoom in",self)
    self.action5.triggered.connect(self.zoomin)

---

我会调整原始的

QPixmap

大小，并将其再次放入

label

    self.scale *= 2

    size = self.pixmap.size()

    scaled_pixmap = self.pixmap.scaled(self.scale * size)

    self.label.setPixmap(scaled_pixmap)

最低工作代码：

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *

class MyApp(QWidget):

    def __init__(self, *args):
        super().__init__(*args)

        self.layout = QVBoxLayout()
        self.setLayout(self.layout)

        self.button_zoom_in = QPushButton('Zoom IN', self)
        self.button_zoom_in.clicked.connect(self.on_zoom_in)
        self.layout.addWidget(self.button_zoom_in)

        self.button_zoom_out = QPushButton('Zoom OUT', self) 
        self.button_zoom_out.clicked.connect(self.on_zoom_out)
        self.layout.addWidget(self.button_zoom_out)

        self.pixmap = QPixmap('image.jpg')

        self.label = QLabel(self)
        self.label.setPixmap(self.pixmap)
        self.layout.addWidget(self.label)

        self.scale = 1

        self.show()

    def on_zoom_in(self, event):
        self.scale *= 2
        self.resize_image()

    def on_zoom_out(self, event):
        self.scale /= 2
        self.resize_image()

    def resize_image(self):
        size = self.pixmap.size()

        scaled_pixmap = self.pixmap.scaled(self.scale * size)

        self.label.setPixmap(scaled_pixmap)

# --- main ---

app = QApplication([])
win = MyApp()
app.exec()

---

编辑：使用

self.height+=100

而不是

self.scale*=2

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *

class MyApp(QWidget):

    def __init__(self, *args):
        super().__init__(*args)

        self.layout = QVBoxLayout()
        self.setLayout(self.layout)

        self.button_zoom_in = QPushButton('Zoom IN', self)
        self.button_zoom_in.clicked.connect(self.on_zoom_in)
        self.layout.addWidget(self.button_zoom_in)

        self.button_zoom_out = QPushButton('Zoom OUT', self) 
        self.button_zoom_out.clicked.connect(self.on_zoom_out)
        self.layout.addWidget(self.button_zoom_out)

        self.pixmap = QPixmap('image.jpg')
        self.height = self.pixmap.height()

        self.label = QLabel(self)
        self.label.setPixmap(self.pixmap)
        self.layout.addWidget(self.label)

        self.show()

    def on_zoom_in(self, event):
        self.height += 100
        self.resize_image()

    def on_zoom_out(self, event):
        self.height -= 100
        self.resize_image()

    def resize_image(self):
        scaled_pixmap = self.pixmap.scaledToHeight(self.height)
        self.label.setPixmap(scaled_pixmap)

# --- main ---

app = QApplication([])
win = MyApp()
app.exec()

---

请提供一个您提供的代码不是MRE，请阅读您尝试缩放标签的链接，但可能您必须缩放原始图像

QPixmap

，然后再次将其放入标签中（以替换以前的图像）。

 def zoomin(self):
    self.hauteur+=100
    self.label.scaledToHeight(self.hauteur)
    self.update()

    self.scale *= 2

    size = self.pixmap.size()

    scaled_pixmap = self.pixmap.scaled(self.scale * size)

    self.label.setPixmap(scaled_pixmap)

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *

class MyApp(QWidget):

    def __init__(self, *args):
        super().__init__(*args)

        self.layout = QVBoxLayout()
        self.setLayout(self.layout)

        self.button_zoom_in = QPushButton('Zoom IN', self)
        self.button_zoom_in.clicked.connect(self.on_zoom_in)
        self.layout.addWidget(self.button_zoom_in)

        self.button_zoom_out = QPushButton('Zoom OUT', self) 
        self.button_zoom_out.clicked.connect(self.on_zoom_out)
        self.layout.addWidget(self.button_zoom_out)

        self.pixmap = QPixmap('image.jpg')

        self.label = QLabel(self)
        self.label.setPixmap(self.pixmap)
        self.layout.addWidget(self.label)

        self.scale = 1

        self.show()

    def on_zoom_in(self, event):
        self.scale *= 2
        self.resize_image()

    def on_zoom_out(self, event):
        self.scale /= 2
        self.resize_image()

    def resize_image(self):
        size = self.pixmap.size()

        scaled_pixmap = self.pixmap.scaled(self.scale * size)

        self.label.setPixmap(scaled_pixmap)

# --- main ---

app = QApplication([])
win = MyApp()
app.exec()

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *

class MyApp(QWidget):

    def __init__(self, *args):
        super().__init__(*args)

        self.layout = QVBoxLayout()
        self.setLayout(self.layout)

        self.button_zoom_in = QPushButton('Zoom IN', self)
        self.button_zoom_in.clicked.connect(self.on_zoom_in)
        self.layout.addWidget(self.button_zoom_in)

        self.button_zoom_out = QPushButton('Zoom OUT', self) 
        self.button_zoom_out.clicked.connect(self.on_zoom_out)
        self.layout.addWidget(self.button_zoom_out)

        self.pixmap = QPixmap('image.jpg')
        self.height = self.pixmap.height()

        self.label = QLabel(self)
        self.label.setPixmap(self.pixmap)
        self.layout.addWidget(self.label)

        self.show()

    def on_zoom_in(self, event):
        self.height += 100
        self.resize_image()

    def on_zoom_out(self, event):
        self.height -= 100
        self.resize_image()

    def resize_image(self):
        scaled_pixmap = self.pixmap.scaledToHeight(self.height)
        self.label.setPixmap(scaled_pixmap)

# --- main ---

app = QApplication([])
win = MyApp()
app.exec()