1.在AndroidManifest.xml中配置请求权限

 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

2.在onCreate(Bundle savedInstanceState)方法中请求权限

//授权请求
        if (Build.VERSION.SDK_INT >= 24) {
            System.out.println("版本正确");
            checkPermission();
        }else {
            System.out.println("版本过低");
        }

权限检测实现代码

private static final int REQUEST_CODE = 1;
    private static String[] PERMISSIONS_STORAGE = {
            "android.permission.READ_EXTERNAL_STORAGE",
            "android.permission.WRITE_EXTERNAL_STORAGE"};
    //授权检测
    private void checkPermission() {
        //权限是否已经赋予
        if (m_activity.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED) {
            //未赋予权限，申请权限
            if (m_activity.shouldShowRequestPermissionRationale(Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                //选择不开启权限的时候，提示用户
                Toast.makeText(m_activity.getApplicationContext() , "请开通相关权限，否则无法正常使用本应用！", Toast.LENGTH_SHORT).show();
            }
            //申请权限
            m_activity.requestPermissions( PERMISSIONS_STORAGE, REQUEST_CODE);

        } else {
            //权限已赋予
            Toast.makeText(m_activity.getApplicationContext(), "已授权成功！", Toast.LENGTH_SHORT).show();
        }
    }

权限请求结果代码

 public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            //权限的申请结果返回
            case REQUEST_CODE: {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    //已授权
                    Toast.makeText(m_activity.getApplicationContext(), "授权成功！", Toast.LENGTH_SHORT).show();
                } else {
                    //未授权
                    Toast.makeText(m_activity.getApplicationContext(), "授权被拒绝！", Toast.LENGTH_SHORT).show();
                }
            }
        }
    }