手机内部存储外部存储
package com.example.lenovo.myapplication;
import android.content.SharedPreferences;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.PrintStream;
public class MainActivity extends AppCompatActivity {
EditText et1;
TextView tv1;
ImageView iv1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et1 = (EditText) findViewById(R.id.et1);
tv1 = (TextView) findViewById(R.id.tv1);
iv1 = (ImageView) findViewById(R.id.iv1);
}
public void bt_1(View v) {
//1-得到SharedPreferences
SharedPreferences sharedPreferences = getSharedPreferences("abc", MODE_PRIVATE);
//2-得到编译器
SharedPreferences.Editor editor = sharedPreferences.edit();
//3-使用Editor添加数据
editor.putString("a", "abcdfe");
editor.putLong("b", 123456);
//4-提交保存
editor.commit();
Toast.makeText(MainActivity.this, "保存成功", Toast.LENGTH_SHORT).show();
}
//读取
public void bt_2(View v) {
SharedPreferences sharedPreferences = getSharedPreferences("abc", MODE_PRIVATE);
String s = sharedPreferences.getString("b", null);
Toast.makeText(MainActivity.this, "key=b" + "value=" + s, Toast.LENGTH_SHORT).show();
}
//写内部文件
public void bt_3(View v) {
//从内存里写入文件
try {
//1-得到内部的存储文件
File file = getFilesDir();
String path = file.getAbsolutePath();
Toast.makeText(MainActivity.this, "path=" + path, Toast.LENGTH_SHORT).show();
//2-用输出流写入文件
FileOutputStream fileOutputStream = openFileOutput("text.txt", MODE_PRIVATE);
//3-写入文件内容
PrintStream printStream = new PrintStream(fileOutputStream);
String str = et1.getText().toString();
printStream.println(str);
//printStream.println("自动换行");
printStream.close();
Toast.makeText(MainActivity.this, "保存成功", Toast.LENGTH_SHORT).show();
} catch (Exception ex) {
Toast.makeText(MainActivity.this, "保存失败", Toast.LENGTH_SHORT).show();
}
}
//
public void bt_4(View v) {
try {
//输入流
FileInputStream fis = openFileInput("text.txt");
//1-定义byte[]
byte[] b = new byte[1024];
int i = 0;//读到的数据长度
String str1 = "";
//2-循环读
while ((i = fis.read(b)) > 0) {
String str = new String(b, 0, i);
str1 += str;
}
fis.close();
tv1.setText(str1);
} catch (Exception ex) {
}
}
public void bt_5(View v) {
try {
//操作assets目录的文件
//1-得到assets目录管理器Manager
AssetManager assetManager = getAssets();
//2-操作资产目录，边读边写入
//1)-先读文件到内存 inputstream
InputStream inputStream = assetManager.open("abc.jpg");
//2)-写文件到目录outputstream
FileOutputStream fileOutputStream = openFileOutput("text.jpg", MODE_PRIVATE);
//先读后写入
byte[] b = new byte[1024];
int i = 0;
while ((i = inputStream.read(b)) > 0) {
fileOutputStream.write(b, 0, i);
}
fileOutputStream.close();
inputStream.close();
Toast.makeText(MainActivity.this, "保存文件成功", Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(MainActivity.this, "保存文件出错", Toast.LENGTH_SHORT).show();
}
}
public void bt_6(View v) {
//3-得到文件路径
String path = getFilesDir().getAbsolutePath() + "/text.jpg";
Toast.makeText(MainActivity.this, "path=" + path, Toast.LENGTH_SHORT).show();
//2-从内部存储的图片得到Bitmap BitmapFactory.decodeFile("文件路径");
Bitmap bm = BitmapFactory.decodeFile(path);
//1-设置图片视图的图片数据来源
iv1.setImageBitmap(bm);
}
public void bt_7(View v) {
//1-判断SC卡是否挂载
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
//得到文本框内容
String str = et1.getText().toString();
try {
//写入
//1-构造输出流
//1）得到文件路径。得到SD卡的根目录
//String path=Environment.getExternalStorageDirectory().getCanonicalPath();
//2)得到包名对应的目录
String path = getExternalFilesDir("Musics").getCanonicalPath();
Toast.makeText(MainActivity.this, "path=" + path, Toast.LENGTH_SHORT).show();
//2）构造
FileOutputStream fos = new FileOutputStream("path");
PrintStream printStream = new PrintStream(fos);
printStream.print(str);
printStream.close();
fos.close();
Toast.makeText(MainActivity.this, "存储成功", Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(MainActivity.this, "存储失败", Toast.LENGTH_SHORT).show();
}
} else {
Toast.makeText(MainActivity.this, "SD没有", Toast.LENGTH_SHORT).show();
}
}
public void bt_8(View v) {
//1-判断SC卡是否挂载
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
try {
String path = getExternalFilesDir("Music").getCanonicalPath() + "/text.jpg";
FileInputStream fls=new FileInputStream(path);
byte[]b=new byte[1024];
int i=0;
String str="";
while ((i=fls.read(b))>0)
{
str+=new String(b,0,i);
}
fls.close();
Toast.makeText(MainActivity.this, "读取成功，文件内容："+str, Toast.LENGTH_SHORT).show();
}
catch (Exception e)
{
Toast.makeText(MainActivity.this, "读取失败", Toast.LENGTH_SHORT).show();
}
}
else
{
Toast.makeText(MainActivity.this, "SD没有", Toast.LENGTH_SHORT).show();
}
}
}
xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.lenovo.myapplication.MainActivity" android:orientation="vertical"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:id="@+id/tv1"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="sp存储" android:onClick="bt_1"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="sp读取" android:onClick="bt_2"/> <EditText android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/et1" android:hint="输入……"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="写内部文件" android:onClick="bt_3"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="读内部文件" android:onClick="bt_4"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="保存资产文件到内部存储" android:onClick="bt_5"/> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/iv1" android:src="@drawable/nnn"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="设置图片指向内部存储" android:onClick="bt_6"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="写入外部存储文件" android:onClick="bt_7"/> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="读取外部存储文件" android:onClick="bt_8"/> </LinearLayout>
