Python+PyQt5开发一个图片尺寸修改器

# -*- coding: UTF-8 -*-
'''
@Project ：测试 
@File    ：test1.py
@IDE     ：PyCharm 
@Author  ：一晌小贪欢（278865463@qq.com）
@Date    ：2025/3/1 21:07 
'''

import sys
from PyQt5.QtWidgets import (QApplication, QWidget, QVBoxLayout, QPushButton,
                             QLabel, QLineEdit, QFileDialog, QHBoxLayout,
                             QCheckBox, QMessageBox, QSpacerItem, QSizePolicy)
from PyQt5.QtGui import QPixmap, QIntValidator, QDragEnterEvent, QDropEvent
from PyQt5.QtCore import Qt
from PIL import Image


class ResizeImageTool(QWidget):
    def __init__(self):
        super().__init__()
        self.width_connected = False
        self.height_connected = False
        self.preview_size = 400  # 预览图片的最大尺寸
        self.initUI()

    def initUI(self):
        self.setWindowTitle('图片大小调整工具')
        self.setMinimumWidth(500)

        # 设置主布局
        self.layout = QVBoxLayout()
        self.layout.setSpacing(10)

        # 添加文件选择区域
        file_layout = QHBoxLayout()
        self.selectBtn = QPushButton('选择图片', self)
        self.selectBtn.clicked.connect(self.selectImage)
        self.filePathLabel = QLabel('未选择文件', self)
        file_layout.addWidget(self.selectBtn)
        file_layout.addWidget(self.filePathLabel)
        self.layout.addLayout(file_layout)

        # 显示图片的Label
        self.imageLabel = QLabel(self)
        self.imageLabel.setAlignment(Qt.AlignCenter)
        self.imageLabel.setMinimumHeight(self.preview_size)
        self.imageLabel.setAcceptDrops(True)  # 启用拖放功能
        self.imageLabel.dragEnterEvent = self.dragEnterEvent
        self.imageLabel.dropEvent = self.dropEvent
        self.layout.addWidget(self.imageLabel)

        # 设置尺寸输入区域
        size_layout = QHBoxLayout()

        # 宽度输入
        width_layout = QVBoxLayout()
        self.widthLabel = QLabel('宽度：', self)
        self.widthInput = QLineEdit(self)
        self.widthInput.setValidator(QIntValidator(1, 9999))
        width_layout.addWidget(self.widthLabel)
        width_layout.addWidget(self.widthInput)

        # 高度输入
        height_layout = QVBoxLayout()
        self.heightLabel = QLabel('高度：', self)
        self.heightInput = QLineEdit(self)
        self.heightInput.setValidator(QIntValidator(1, 9999))
        height_layout.addWidget(self.heightLabel)
        height_layout.addWidget(self.heightInput)

        size_layout.addLayout(width_layout)
        size_layout.addLayout(height_layout)
        self.layout.addLayout(size_layout)

        # 添加锁定比例复选框
        self.lockAspectRatioCheckBox = QCheckBox('锁定比例', self)
        self.lockAspectRatioCheckBox.setChecked(True)
        self.lockAspectRatioCheckBox.stateChanged.connect(self.onLockAspectRatioChanged)
        self.layout.addWidget(self.lockAspectRatioCheckBox)

        # 添加保存按钮
        self.saveBtn = QPushButton('保存调整后的图片', self)
        self.saveBtn.clicked.connect(self.saveImage)
        self.saveBtn.setEnabled(False)
        self.layout.addWidget(self.saveBtn)

        # 添加状态标签
        self.statusLabel = QLabel('', self)
        self.statusLabel.setAlignment(Qt.AlignCenter)
        self.layout.addWidget(self.statusLabel)

        # 设置主窗口的布局
        self.setLayout(self.layout)

        # 初始化变量
        self.imagePath = None
        self.originalWidth = None
        self.originalHeight = None

        # 初始状态下启用锁定比例
        self.onLockAspectRatioChanged(Qt.Checked)

    def dragEnterEvent(self, event: QDragEnterEvent):
        if event.mimeData().hasUrls():
            event.acceptProposedAction()

    def dropEvent(self, event: QDropEvent):
        if event.mimeData().hasUrls():
            filePath = event.mimeData().urls()[0].toLocalFile()
            if filePath.lower().endswith(('.png', '.jpg', '.jpeg', '.bmp')):
                self.loadImage(filePath)

    def loadImage(self, filePath):
        try:
            self.imagePath = filePath
            self.filePathLabel.setText(filePath)

            # 使用Pillow库读取图片原始尺寸
            img = Image.open(filePath)
            self.originalWidth, self.originalHeight = img.size

            # 更新预览图片
            self.updatePreview()

            # 初始化输入框
            self.widthInput.setText(str(self.originalWidth))
            self.heightInput.setText(str(self.originalHeight))

            # 启用保存按钮
            self.saveBtn.setEnabled(True)
            self.statusLabel.setText('图片已加载')

        except Exception as e:
            QMessageBox.critical(self, '错误', f'加载图片时出错：{str(e)}')

    def selectImage(self):
        filePath, _ = QFileDialog.getOpenFileName(
            self, '选择图片', '',
            'Images (*.png *.xpm *.jpg *.jpeg *.bmp)'
        )
        if filePath:
            self.loadImage(filePath)

    def updatePreview(self):
        if not self.imagePath:
            return

        pixmap = QPixmap(self.imagePath)
        scaled_pixmap = pixmap.scaled(
            self.preview_size,
            self.preview_size,
            Qt.KeepAspectRatio,
            Qt.SmoothTransformation
        )
        self.imageLabel.setPixmap(scaled_pixmap)

    def onLockAspectRatioChanged(self, state):
        if state == Qt.Checked:
            if not self.width_connected:
                self.widthInput.textChanged.connect(self.updateHeightFromWidth)
                self.width_connected = True
            if not self.height_connected:
                self.heightInput.textChanged.connect(self.updateWidthFromHeight)
                self.height_connected = True
        else:
            if self.width_connected:
                self.widthInput.textChanged.disconnect(self.updateHeightFromWidth)
                self.width_connected = False
            if self.height_connected:
                self.heightInput.textChanged.disconnect(self.updateWidthFromHeight)
                self.height_connected = False

    def updateHeightFromWidth(self):
        if not self.originalWidth or not self.originalHeight:
            return

        try:
            if self.height_connected:
                self.heightInput.textChanged.disconnect(self.updateWidthFromHeight)

            width = int(self.widthInput.text() or 0)
            if width > 0:
                height = int((self.originalHeight / self.originalWidth) * width)
                self.heightInput.setText(str(height))

            if self.height_connected:
                self.heightInput.textChanged.connect(self.updateWidthFromHeight)
        except ValueError:
            pass

    def updateWidthFromHeight(self):
        if not self.originalWidth or not self.originalHeight:
            return

        try:
            if self.width_connected:
                self.widthInput.textChanged.disconnect(self.updateHeightFromWidth)

            height = int(self.heightInput.text() or 0)
            if height > 0:
                width = int((self.originalWidth / self.originalHeight) * height)
                self.widthInput.setText(str(width))

            if self.width_connected:
                self.widthInput.textChanged.connect(self.updateHeightFromWidth)
        except ValueError:
            pass

    def saveImage(self):
        if not self.imagePath:
            return

        try:
            width = int(self.widthInput.text())
            height = int(self.heightInput.text())

            if width <= 0 or height <= 0:
                raise ValueError("尺寸必须大于0")

            img = Image.open(self.imagePath)
            img = img.resize((width, height), Image.Resampling.LANCZOS)

            savePath, _ = QFileDialog.getSaveFileName(
                self, '保存图片', '',
                'PNG (*.png);;JPEG (*.jpg *.jpeg);;BMP (*.bmp)'
            )

            if savePath:
                img.save(savePath)
                self.statusLabel.setText(f'图片已保存到: {savePath}')
                QMessageBox.information(self, '成功', '图片保存成功！')

        except ValueError as e:
            QMessageBox.warning(self, '警告', f"输入错误：{str(e)}")
        except Exception as e:
            QMessageBox.critical(self, '错误', f"保存失败：{str(e)}")


if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = ResizeImageTool()
    window.show()
    sys.exit(app.exec_())