SD卡读写

来源：互联网发布：抑制性欲的药知乎编辑：程序博客网时间：2024/05/22 03:10
package com.example.menu;import android.os.Bundle;import android.os.Environment;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStreamReader;public class MainActivity extends AppCompatActivity {    package net.bwie.externalstorage;    import android.os.Bundle;    import android.os.Environment;    import android.support.v7.app.AppCompatActivity;    import android.view.View;    import android.widget.Button;    import android.widget.EditText;    import android.widget.TextView;    import android.widget.Toast;    import java.io.BufferedReader;    import java.io.File;    import java.io.FileInputStream;    import java.io.FileOutputStream;    import java.io.IOException;    import java.io.InputStreamReader;    public class MainActivity extends AppCompatActivity implements View.OnClickListener {        protected TextView mResultTv;        protected EditText mEditText;        protected Button mWriteBtn;        protected Button mReadBtn;        public static final String FILE_NAME = "1511c.txt";        @Override        protected void onCreate(Bundle savedInstanceState) {            super.onCreate(savedInstanceState);            super.setContentView(R.layout.activity_main);            initView();        }        @Override        public void onClick(View view) {            // 外部存储公共路径，例如DCIM, DOWNLOAD, MUSIC等            File publicPath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);            // 外部存储私有路径            File privatePath = this.getExternalFilesDir(null);// 代表Android/包名/files路径            // 自定义路径            File myPath = Environment.getExternalStorageDirectory();// 外部存储根目录            // 文件路径+文件名            File file = new File(publicPath, FILE_NAME);            if (view.getId() == R.id.write_btn) {// 写入数据                String content = mEditText.getText().toString();                writeFile(content, file);            } else if (view.getId() == R.id.read_btn) {// 读取数据                String result = readFile(file);                mResultTv.setText(result);            }        }        // 读取文件        private String readFile(File filePath) {            BufferedReader br = null;            try {                br = new BufferedReader(new InputStreamReader(new FileInputStream(filePath)));                String result = "";// 总数据                String line = "";// 读取的每一行数据                while ((line = br.readLine()) != null) {                    result += line;                }                return result;            } catch (Exception e) {                e.printStackTrace();            } finally {                if (br != null) {                    try {                        br.close();                    } catch (IOException e) {                        e.printStackTrace();                    }                }            }            return null;        }        // 写入数据        private void writeFile(String content, File filePath) {            // 文件名、文件路径、文件内容            FileOutputStream fos = null;            try {                fos = new FileOutputStream(filePath);                fos.write(content.getBytes());// 字符串转字节数组                Toast.makeText(this, "写入成功", Toast.LENGTH_SHORT).show();            } catch (Exception e) {                e.printStackTrace();            } finally {                if (fos != null) {                    try {                        fos.close();                    } catch (IOException e) {                        e.printStackTrace();                    }                }            }        }        private void initView() {            mResultTv = (TextView) findViewById(R.id.result_tv);            mEditText = (EditText) findViewById(R.id.edit_text);            mWriteBtn = (Button) findViewById(R.id.write_btn);            mWriteBtn.setOnClickListener(MainActivity.this);            mReadBtn = (Button) findViewById(R.id.read_btn);            mReadBtn.setOnClickListener(MainActivity.this);        }    }}
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