Android Studio 使用内部存储上的文件创建 diconary

Question

我目前在 Android 的 Notes 应用程序中工作。 问题：我不知道如何保存 txt。我的应用程序的文件在我的内部存储上。我已经使用外部存储对其进行了编码。这是我的代码（MainActivity.java）

`package de.tkdevelopment.notizen;

import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Environment;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;


public class MainActivity extends AppCompatActivity {


    Button btn;
    EditText editText;
    File ordner;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);




        ordner = new File(Environment.getExternalStorageDirectory(), "NotizenApp"); //Ordnername
        if(!ordner.exists()){
            ordner.mkdirs();
        }

        editText = (EditText) findViewById(R.id.editText);
        btn = (Button) findViewById(R.id.button);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (editText.getText().length() > 0){ //Wenn Text länger als 0 dann Spiechern

                    File notizdatei = new File(ordner, "Notiz_" + System.currentTimeMillis() + ".txt");
                    try {
                        OutputStream outputStream = new FileOutputStream(notizdatei);
                        outputStream.write(editText.getText().toString().getBytes());
                        outputStream.close();
                        editText.setText(null);
                        Toast.makeText(getApplicationContext(), "Notiz gespeichert", Toast.LENGTH_LONG);
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }


                }else { //Sonst nicht Speichern
                    Toast.makeText(getApplicationContext(), "Kein Text vorhanden", Toast.LENGTH_SHORT).show();


                }
            }
        });


    }




    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_view_notes) {

            if(ordner.listFiles().length > 0){

                startActivity(new Intent(MainActivity.this, Notizen_auslesen.class));

            } else {
                Toast.makeText(getApplicationContext(), "Keine Notizen vorhanden", Toast.LENGTH_SHORT).show();
            }



            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}
`

Answer 1

将此方法添加到您的活动中：

public String storeToInternalStorage(Context context,String data) {
    ContextWrapper cw = new ContextWrapper(context);
    // path to /data/data/yourapp/app_data/PrivateFiles
    File directory = cw.getDir("PrivateFiles", Context.MODE_PRIVATE);
    File file = new File(directory, "filename.txt");
    try {

        FileOutputStream fileOutputStream = new FileOutputStream(file);
        fileOutputStream.write(data.getBytes());
        fileOutputStream.close();

    } catch (IOException e) {
        e.printStackTrace();
    }
    return file.getAbsolutePath();
}  

然后像这样使用它：

btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (editText.getText().length() > 0){
                String data = editText.getText().toString().trim();
                String fileStoredPath = storeToInternalStorage(this, data);
                Log.d("TAG","File is stored at:" + fileStoredPath);
             }
});