Android 6.0以上动态申请文件读写权限

https://blog.csdn.net/qq_34330286/article/details/79660059

自Android 6.0开始，Google开始对系统权限做出严格的要求，有些权限必须用户同意才能调用相应功能，所以开发者需要调用权限申请的代码，弹出一个小窗口，向用户动态申请权限。

以下是动态申请文件读写权限的过程：

1.读与写的权限先定义到静态字符数组中：

        private static String[] PERMISSIONS_STORAGE = {
                Manifest.permission.READ_EXTERNAL_STORAGE,
                Manifest.permission.WRITE_EXTERNAL_STORAGE};

2.首先判断当前系统是否是Android6.0(对应API 23)以及以上，如果是则判断是否含有了写文件的权限，如果没有则调用动态申请权限的代码，ActivityCompat.requestPermission方法的第一个参数是目标Activity,填写this即可，第二个参数是String[]字符数组类型的权限集，第三个即请求码：

    if (Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP) {
                if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(this, PERMISSIONS_STORAGE, REQUEST_PERMISSION_CODE);
                }
            }

3.回调函数，申请权限后回调onRequestPermissionResult函数，第一个参数为请求码，第二个参数是刚刚请求的权限集，第三个参数是请求结果，0表示授权成功，-1表示授权失败：

    @Override
        public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
            if (requestCode == REQUEST_PERMISSION_CODE) {
                for (int i = 0; i < permissions.length; i++) {
                    Log.i("MainActivity", "申请的权限为：" + permissions[i] + ",申请结果：" + grantResults[i]);
                }
            }
        }

4.完整代码：

    public class MainActivity extends AppCompatActivity {
        //读写权限
        private static String[] PERMISSIONS_STORAGE = {
                Manifest.permission.READ_EXTERNAL_STORAGE,
                Manifest.permission.WRITE_EXTERNAL_STORAGE};
        //请求状态码
        private static int REQUEST_PERMISSION_CODE = 1;
     
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
     
            if (Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP) {
                if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(this, PERMISSIONS_STORAGE, REQUEST_PERMISSION_CODE);
                }
            }
        }
     
        @Override
        public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
            if (requestCode == REQUEST_PERMISSION_CODE) {
                for (int i = 0; i < permissions.length; i++) {
                    Log.i("MainActivity", "申请的权限为：" + permissions[i] + ",申请结果：" + grantResults[i]);
                }
            }
        }
    }

Android6.0以上文件读写权限
---------------------  
作者：极客开发者  
来源：CSDN  
原文：https://blog.csdn.net/qq_34330286/article/details/79660059  
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