如何从 Android Studio 表布局生成 CSV 文件

Question

I'm developing an android app which store user input in SQLite database. and displays it in TableLayout in android studio. Now I want to generate CSV file from the contents of that Table Layout.

I need a button to generate the CSV file. Thanks in advance. I'm new to StackoverFlow and coding. So forgive me If my question wasn't right.

I really need this code to complete my project. Thanks in Advance.

Answer 1

hello here is my sample simple code for creating csv from database,

codes read data by Database_helper and put fetched data inside an arrayList then put every item of arrayList inside of csvfile (csvFile.csv) and store for creating csv you need follow this format for every row of csvFile < item1;item_2;item_3;...;item_n> every column seprate by;(semicolon) and write in a file whit.csv type NOTICE: this code works in android version 6 (for android 11 need another methods for creating file in storage but main concept for creating csv is same as this code)

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.content.pm.PackageManager;
import android.database.sqlite.SQLiteException;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;

public class CsvMaker extends AppCompatActivity {
    ArrayList<NewsInformation> news = new ArrayList<>();
    private DatabaseHandler db;
    Button csv_maker;
    TextView txt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_csv_maker);

        csv_maker = (Button) findViewById(R.id.csv_maker);
        txt = (TextView) findViewById(R.id.csv_address);

        csv_maker.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                hasStoragePermission(1);
            }
        });


    }

    public void createCsv() {
        db = new DatabaseHandler(this);
        try {
            db.open();
            ArrayList<NewsInformation> news = db.getAllNews();
            db.close();
            exportTheDB();

        } catch (SQLException | IOException throwables) {
            throwables.printStackTrace();

        }
    }


    private void exportTheDB() throws IOException {
        File myFile;
        try {

            myFile = new File(Environment.getExternalStoragePublicDirectory(""), "csvFile.csv");
            myFile.createNewFile();
            FileOutputStream fOut = new FileOutputStream(myFile);
            OutputStreamWriter myOutWriter = new OutputStreamWriter(fOut);
            myOutWriter.append("News_Description;News_Image;News_link;News_Title");
            myOutWriter.append("\n");


            for (int i = 0; i < news.size(); ++i) {
                String description = news.get(i).description;
                String image = news.get(i).image;
                String link = news.get(i).link;
                String title = news.get(i).title;
                myOutWriter.append(description + ";" + image + ";" + link + ";" + title);
                myOutWriter.append("\n");
            }


            myOutWriter.close();
            fOut.close();
            txt.setText(myFile.getAbsolutePath());


        } catch (SQLiteException se) {
            Log.e(getClass().getSimpleName(), "Could not create or Open the database");
        }


    }

    private void hasStoragePermission(int requestCode) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
                //  return false;
            } else {
                createCsv();
                // return true;
            }
        } else {
            //return true;
            createCsv();
        }
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            if (requestCode == 1) {
                createCsv();
            }


        }
    }
}