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SharedPreferences模式

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![image.png](https://img.haomeiwen.com/i12474760/8ab80938a1bdc110.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

// 存储的操作 
 String strName =  editTextName.getText().toString();
                String strPwd =  editTextPwd.getText().toString();
                // SharedPreferences 读取
                Log.e("strName",strName);
                Log.e("passWord",strPwd);
                if(strName.equals("admin") && strPwd.equals("123")) {
                    // 2.1  存储信息到SharedPreferences 参数1：参数名称，参数2： 参数模式
                    SharedPreferences SharedPreferences = getSharedPreferences("myName",MODE_PRIVATE);
                    // 2.2 获取editor对象
                    android.content.SharedPreferences.Editor editor = SharedPreferences.edit();
                    // 2.3.存储信息
                    editor.putString("userName",strName);
                    editor.putString("passWord",strPwd);
                    // 2.4 指定提交操作
                    editor.commit();

找到存储的数据在哪里

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    // 获取数据操作
    // 获取参数
        SharedPreferences shared = getSharedPreferences("myName",MODE_PRIVATE);
        //获取参数的默认值
        String user =  shared.getString("userName","");
        String pwd = shared.getString("passWord","");
        editTextName.setText(user);
        editTextPwd.setText(pwd);

外部存储

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// 点击按钮去写入文件和读取文件操作
    public void FnOperate(View view) {
        if(!isGrantExternalRW(this)){ // 动态授权
            return;
        }
        // Environment.getExternalStorageDirectory().getAbsolutePath() 绝对路径
        String path = Environment.getExternalStorageDirectory().getAbsolutePath()+"/pjtest.txt";
//        Environment.getExternalStorageState().equals("mounted") // 是否有内存卡
        Log.e("TAG",path+Environment.getExternalStorageState().equals("mounted"));
        switch (view.getId()){
            case R.id.save:
                File f = new File(path);
                try {
                    if (!f.exists()) {
                        f.createNewFile();
                    }

                    FileOutputStream fos = new FileOutputStream(path,true);
                    String str = infoEdt.getText().toString();
                    fos.write(str.getBytes());
                }catch (IOException ioe){
                    ioe.printStackTrace();
                }
            case R.id.read:
                // tex
                try {
                    FileInputStream fis = new FileInputStream(path);
                    byte[] b = new byte[1024];
                    int len = fis.read(b);
                    String str2 = new String(b,0,len);
                    Log.e("str2",str2);
                    tex.setText(str2);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                break;
        }
    }

动态授权操作

// 动态申请权限
   public static boolean isGrantExternalRW(Activity activity) {
       if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && activity.checkSelfPermission(
               Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
           activity.requestPermissions(new String[]{
                   Manifest.permission.READ_EXTERNAL_STORAGE,
                   Manifest.permission.WRITE_EXTERNAL_STORAGE
           }, 1);
           return false;
       }
       return true;
   }

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新版本存储地址

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内部存储

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