读取指定文件夹下.TXT文件并显示在ListView控件中，相关代码如下：

MainActivity

package com.example.txtlist;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import androidx.appcompat.app.AppCompatActivity;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Arrays;
import static android.content.ContentValues.TAG;


public class MainActivity extends AppCompatActivity {
    private ListView lv;
    ArrayList<String> name;

    @Override
    public  void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.e(TAG, "list. name: " + Environment.getExternalStorageDirectory());
      lv=(ListView )findViewById(R.id.lv);
        name = new ArrayList<String>();
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
          //  File path = Environment.getExternalStorageDirectory();// 获得sd卡路径
             @SuppressLint("SdCardPath") File path = new File("/data/data/com.example.txtlist/files");//读取指定路径下的txt文件
            File[] files = path.listFiles();
            getFileName(files);
        }
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_list_item_1 ,name);

        lv.setAdapter(adapter);

    }
    private void getFileName(File[] files) {
        if (files != null) {// 先判断目录是否为空，否则会报空指针
            for (File file : files) {
                if (file.isDirectory()) {
                    getFileName(file.listFiles());
                } else {
                    String fileName = file.getName();
                    if (fileName.endsWith(".txt")) {
                        name.add(fileName);//将文件名添加到ListView
                    }
                }
            }
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
       >
    </ListView>
</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.txtlist">
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
        tools:ignore="ScopedStorage" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"
        tools:ignore="ProtectedPermissions" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:requestLegacyExternalStorage="true"
        android:theme="@style/Theme.TXTLIST">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

最终的效果如下图：

文件：

代码：

try:
    file=open('food.txt',"r")     #以读模式打开文件
except FileNotFoundError:          #如果文件不存在，给提示
    print("file is not found")
else:
    contents=file.readlines()       #读取全部行
    for content in contents:       #显示一行
        print(content.split(',')[0])   #每行用逗号分隔后，取第一个元素

运行结果：

原图：

自己先处理成黑白照片

效果显示：（txt字体大小为1）

效果显示：（txt字体大小为2）

python源码

#导入cv模块
import cv2 as cv
import random
import numpy as np
# # =================================存取图像=====================================
# 60号宋体字母占用字符比较
xiangsi={
    "I":198,"V":229,"L":230,"U":235,"C":236,"Y":236,"T":245,"J":248,"A":262,"X":265,"Z":270,"N":276,"G":281,"F":284,"P":303,"O":306,"E":322,"K":339,"D":357,"W":373,"R":380,"H":384,"Q":391,"B":391,"S":292,"M":432
}

I_value=180   # I映射为不同的值表示亮度，
M_value=50   # M映射为50
x=(M_value-I_value)/(xiangsi['M']-xiangsi['I'])
b=I_value-xiangsi['I']*x
#归一化，后数组递减排列
for zimu in xiangsi:
    xiangsi[zimu]=int(x*xiangsi[zimu]+b)   # 将字母表示为对应的黑度值。

print(xiangsi)

# # 直接读取单通道灰度图
gray_img = cv.imread('hui.jpg', cv.IMREAD_GRAYSCALE)
gray_img = cv.resize(gray_img,(int(gray_img.shape[1]),int(gray_img.shape[0]/1.7)),interpolation=cv.INTER_CUBIC)
# cv.imshow('iker', gray_img)
# cv.waitKey(0)
print(gray_img.shape)   # 先是高度， 再是宽度
file = open('img.txt',mode='w')



for row in range(gray_img.shape[0]):
    for col in range(gray_img.shape[1]):
        pzimu=" "
        cansee=False
        for zimu in xiangsi:
            if (gray_img[row][col] > xiangsi[zimu]):
                file.write(pzimu)
                cansee=True
                break
            else:
                pzimu=zimu
        if(not cansee):file.write(pzimu)
    file.write('\n')
file.close()