系统Api检查权限

2020-04-23

 /**
     * 检查权限
     *
     * @return
     */
    private boolean checkPermission() {
        //检查权限（NEED_PERMISSION）是否被授权 PackageManager.PERMISSION_GRANTED表示同意授权
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            //用户已经拒绝过一次，再次弹出权限申请对话框需要给用户一个解释
            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                Toast.makeText(this, "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
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
            return false;
        } else {
            Toast.makeText(this, "已经授权 存储权限！", Toast.LENGTH_SHORT).show();
            Log.e("", "checkPermission: 已经授权！");
            return true;
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        boolean flag = true; //是否全部权限都同意
        for (int i = 0; i < permissions.length; i++) {
            if (grantResults[i] == -1) { //如果有一个没同意,-1是没同意; 0是同意
                flag = false;
                break;
            }
        }

        //如果都同意了
        if (flag) {
            // TODO:  做权限同意后才能做的事

        }

    }