Android 5.1.1删除USB U盘文件

Question

一直获取不到写的权限，只有读的权限。
代码如下：

File f=new File(homedir,file);    
        f.setExecutable(true, false);
        f.setReadable(true, false);
        f.setWritable(true, false);
        if(f.canWrite())
            Log.i("rrrrrrr","file can write");
        else
            Log.i("rrrrrrr","file cannot write");
        f.delete();
        this.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(f)));

设备为Android 5.1.1电视，用es文件浏览器可以删除U盘文件，但是需要确认对话框，现尚无法查明该机制

Answer 1

Starting from Android 4.4, Google has introduced a new set of APIs, namely Storage Access Framework (SAF), a storage access framework that can be used to read and write content on the SD card.

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