以上程序报错：读取文件错误：Excel file format cannot be determined, you must specify an engine manually.

抱歉，Excel文件格式无法确定的错误可能是由于缺少适当的pandas的Excel读取引擎所致。你可以尝试使用openpyxl库来指定读取引擎。请尝试使用以下修改后的代码：

import os
import csv
import pandas as pd
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.filechooser import FileChooserListView

class MainLayout(BoxLayout):
    def __init__(self, **kwargs):
        super(MainLayout, self).__init__(**kwargs)
        self.orientation = 'vertical'

        self.file_chooser = FileChooserListView()
        self.add_widget(self.file_chooser)

        self.select_button = Button(text='选择文件', size_hint=(1, 0.1))
        self.select_button.bind(on_release=self.select_file)
        self.add_widget(self.select_button)

        self.read_button = Button(text='读取文件', size_hint=(1, 0.1))
        self.read_button.bind(on_release=self.read_files)
        self.add_widget(self.read_button)

        self.result_label = Label(text='', size_hint=(1, 0.4))
        self.add_widget(self.result_label)

        self.save_button = Button(text='保存结果', size_hint=(1, 0.1))
        self.save_button.bind(on_release=self.save_result)
        self.add_widget(self.save_button)

        self.exit_button = Button(text='退出', size_hint=(1, 0.1))
        self.exit_button.bind(on_release=self.exit_app)
        self.add_widget(self.exit_button)

    def select_file(self, instance):
        selected_file = self.file_chooser.selection and self.file_chooser.selection[0]
        if selected_file:
            self.selected_path = selected_file

    def read_files(self, instance):
        try:
            files = [f for f in os.listdir(self.selected_path) if f.startswith('Cogging_') and not f.endswith('+.xlsx')]
            result = ''
            for file in files:
                file_path = os.path.join(self.selected_path, file)
                df = pd.read_excel(file_path, engine='openpyxl')
                i17_value = df['I17'].values[0]
                i7219_value = df['I7219'].values[0]
                result += f'{file}: cogging-CW_pk_to_pk(abs): {i17_value}, cogging-CCW_pk_to_pk(abs): {i7219_value}\n'
            self.result_label.text = result
        except Exception as e:
            self.result_label.text = f'读取文件错误: {str(e)}'

    def save_result(self, instance):
        try:
            files = [f for f in os.listdir(self.selected_path) if f.startswith('Cogging_') and not f.endswith('+.xlsx')]
            csv_path = os.path.join(self.selected_path, '筛选cogging.csv')
            with open(csv_path, 'w', newline='') as csvfile:
                writer = csv.writer(csvfile)
                writer.writerow(['文件名', 'cogging-CW_pk_to_pk(abs)', 'cogging-CCW_pk_to_pk(abs)'])
                for file in files:
                    file_path = os.path.join(self.selected_path, file)
                    df = pd.read_excel(file_path, engine='openpyxl')
                    i17_value = df['I17'].values[0]
                    i7219_value = df['I7219'].values[0]
                    writer.writerow([file, i17_value, i7219_value])
            self.result_label.text = '保存成功'
        except Exception as e:
            self.result_label.text = f'保存失败: {str(e)}'

    def exit_app(self, instance):
        App.get_running_app().stop()

class MyApp(App):
    def build(self):
        return MainLayout()

if __name__ == '__main__':
    MyApp().run()

请确保在运行代码之前已安装了openpyxl库：

pip install openpyxl

希望这次能够成功读取Excel文件并解决问题。如有其他问题，请随时提问！