[移动开发]怎么解决Android 10无法随意创建文件

• 创建文件所需要权限

//可创建和删除文件权限
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS">
//存储读写权限
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

• 6.0动态授权

 ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 0); 

• 申请权限监听

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        if (!hasAllPermissionsGranted(grantResults)) {
            return;
        }
        switch (requestCode) {
            case 0:
                Toast.makeText(getApplicationContext(), "已申请权限", Toast.LENGTH_SHORT).show();
            default:
                super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }

解决方式：

1.使用Android10规定的文件夹做操作

2.将gradle中的编译环境，SDK的版本号修改到29以下

3.清单文件加入下面这句停用分区存储即可随意创建文件夹

 <application
        android:requestLegacyExternalStorage="true">
    </application>

测试 （2）和（3）在SDcard根目录成功创建文件

 /**
     * sdcard根目录路径
     *
     * @return
     */
    public static String rootSDPath(Context context){
        String rootPath = "" ;

        /**
         * 是否插入外部SDCard
         */
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
            /*文件管理根目录*/
            File rootFile = Environment.getExternalStorageDirectory();
            rootPath = rootFile.getPath();
        }else {
            /*如果没有插内存卡*/
            File cacheDir=context.getCacheDir() ;
            rootPath = cacheDir.getPath();
        }
        try {
            PackageManager packageManager = context.getPackageManager() ;
            ApplicationInfo info = packageManager.getApplicationInfo(context.getPackageName(), 0);
            File file = new File(rootPath + File.separator + info.loadLabel(packageManager));
            if (!file.exists()){
                file.mkdir();
            }
            Log.v(TAG,"[rootPath]->file="+info.loadLabel(packageManager));
            return file.getPath();
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return "";
    }