内部及外部SD卡存储空间存储

来源：互联网发布：知乎亦庄锋创科技园编辑：程序博客网时间：2024/05/16 10:32
package com.zdsoft.file1206;import android.content.Context;import android.os.Environment;import android.os.StatFs;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private EditText et_name, et_content;    private Button bt_write, bt_read, bt_write_sd, bt_read_sd;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        listener();    }    private void initView() {        et_name = (EditText) findViewById(R.id.et_name);        et_content = (EditText) findViewById(R.id.et_content);        bt_write = (Button) findViewById(R.id.bt_write);        bt_read = (Button) findViewById(R.id.bt_read);        bt_write_sd = (Button) findViewById(R.id.bt_write_sd);        bt_read_sd = (Button) findViewById(R.id.bt_read_sd);    }    private void listener() {        bt_write.setOnClickListener(this);        bt_read.setOnClickListener(this);        bt_write_sd.setOnClickListener(this);        bt_read_sd.setOnClickListener(this);    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.bt_write:                write();                break;            case R.id.bt_read:                read();                break;            case R.id.bt_write_sd:                writeSD();                break;            case R.id.bt_read_sd:                readSD();                break;            default:                break;        }    }    private void write() {        try {            FileOutputStream fos = openFileOutput(et_name.getText().toString(), Context.MODE_APPEND);            fos.write(et_content.getText().toString().getBytes());            fos.close();            Toast.makeText(MainActivity.this, "写入成功", Toast.LENGTH_SHORT).show();        } catch (Exception e) {            e.printStackTrace();        }    }    private void read() {        try {            FileInputStream fis = openFileInput(et_name.getText().toString());            byte[] b = new byte[1024];            int num = 0;            StringBuffer sb = new StringBuffer();            while ((num = fis.read(b)) != -1) {                sb.append(new String(b, 0, num));            }            Toast.makeText(MainActivity.this, sb.toString(), Toast.LENGTH_SHORT).show();            fis.close();        } catch (Exception e) {            e.printStackTrace();        }    }    private void writeSD() {        try {//            if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {//                Toast.makeText(MainActivity.this, "内存卡不存在", Toast.LENGTH_SHORT).show();//                return;//            }            File file = new File(Environment.getExternalStorageDirectory() + "/" + et_name.getText().toString());            FileOutputStream fos = new FileOutputStream(file);            fos.write(et_content.getText().toString().getBytes());            fos.close();            Toast.makeText(MainActivity.this, "写入成功", Toast.LENGTH_SHORT).show();        } catch (Exception e) {            e.printStackTrace();        }    }    private void readSD() {        try {            File file = new File(Environment.getExternalStorageDirectory() + "/" + et_name.getText().toString());            FileInputStream fis = new FileInputStream(file);            byte[] b = new byte[1024];            int num = 0;            StringBuffer sb = new StringBuffer();            while ((num = fis.read(b)) != -1) {                sb.append(new String(b, 0, num));            }            Toast.makeText(MainActivity.this, sb.toString(), Toast.LENGTH_SHORT).show();            fis.close();        } catch (Exception e) {            e.printStackTrace();        }    }}
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
加SD卡权限
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