文件存储是Android中数据存储的基本方式之一，Android提供了openFileOutput和openFileInput两个方法来提供FileOutStream和FileInputStream，文件将会存储在APP的数据目录中（一般是/data/data/APP包名)。
下面是一个简单的示例
FileStorageActivity的布局文件如下：
代码语言：html复制<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="30dp"
tools:context=".FileStorageActivity">
<EditText
android:id="@ id/fileEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="30dp" />
<Button
android:id="@ id/fileWriteButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="写入数据" />
<Button
android:id="@ id/fileReadButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="读取数据" />
</LinearLayout>FileStorageActivity
代码语言：java复制package cn.titan6.data.storage.demo
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.Button
import android.widget.EditText
import java.io.*
class FileStorageActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_file_storage)
val editText: EditText = findViewById(R.id.fileEditText)
val writeButton: Button = findViewById(R.id.fileWriteButton)
val readButton: Button = findViewById(R.id.fileReadButton)
writeButton.setOnClickListener {
saveFileData(editText.text.toString())
Log.i("FileStorageActivity", "Save data finished")
editText.setText("")
}
readButton.setOnClickListener {
val str = readFileData()
Log.i("FileStorageActivity", "Read data finished")
editText.setText(str)
}
}
private fun saveFileData(str: String) {
val openFileOutput = openFileOutput("data", MODE_PRIVATE)
val writer = BufferedWriter(OutputStreamWriter(openFileOutput))
writer.use {
it.write(str)
}
}
private fun readFileData(): String {
val content = StringBuilder()
val input = openFileInput("data")
val reader = BufferedReader(InputStreamReader(input))
reader.use {
reader.forEachLine {
content.append(it)
}
}
return content.toString()
}
}本文为本人原创文章，同步发布于Titan笔记
https://www.titan6.cn/archives/343.html
