一、在AndroidManifest.xml中加入android:requestLegacyExternalStorage="true" ，如下：

<?xml version="1.0" encoding="utf-8"?>                                                                                                

二，动态申请权限

private void initPermission(Activity activity){        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {            if (ContextCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED                    ||ContextCompat.checkSelfPermission(activity, Manifest.permission.READ_SMS) != PackageManager.PERMISSION_GRANTED            ) {                // 检查权限状态                if (ActivityCompat.shouldShowRequestPermissionRationale(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {                    //  用户彻底拒绝授予权限                } else {                    //  用户未彻底拒绝授予权限                    ActivityCompat.requestPermissions(activity, PermissionUtil.PERMISSIONS, PermissionUtil.REQUEST);                }            }else{                Toast.makeText(activity,"已经授权 ： "+Manifest.permission.WRITE_EXTERNAL_STORAGE,Toast.LENGTH_SHORT).show();            }        }    }    @Override    public void  onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {        super.onRequestPermissionsResult(requestCode, permissions, grantResults);        if (requestCode == 1) {            for (int i=0;i

public class PermissionUtil {    public static final int REQUEST = 1;    public static String[] PERMISSIONS = {            Manifest.permission.READ_EXTERNAL_STORAGE,            Manifest.permission.WRITE_EXTERNAL_STORAGE,            Manifest.permission.READ_SMS};}