Question

我想在我的应用程序中显示内部存储的所有视频文件名称。

Environment.getExternalStorageDirectory：我试过这个。另外首先我检查ExternalStorageState是否为null。

我的设备没有任何SD卡存在。那么如何处理？ P.S我正在使用Moto G（第2版）设备。

我试过了： -

How to display files in listView?

How to get android device with Internal Downloader folder path

Answer 1

这是我可以访问内部存储文件的尝试。

https://developer.android.com/training/permissions/requesting.html

从上面的链接中我获得了有关使用权限的重要信息 api level＆gt; 23所以存在权限问题，因为我无法访问内部存储目录。

最终代码： -

public class MainActivity extends Activity {

ListView lv;
private static final int MY_PERMISSIONS_REQUEST_READ_CONTACTS = 1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    lv = (ListView) findViewById(R.id.list);


    if (ContextCompat.checkSelfPermission(MainActivity.this,
            Manifest.permission.READ_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED) {

        // Should we show an explanation?
        if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                Manifest.permission.READ_EXTERNAL_STORAGE)) {


        } else {

            // No explanation needed, we can request the permission.

            ActivityCompat.requestPermissions(MainActivity.this,
                    new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
                    MY_PERMISSIONS_REQUEST_READ_CONTACTS);

            // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
            // app-defined int constant. The callback method gets the
            // result of the request.


        }
    } else {

        ArrayList<String> filesinfolder = GetFiles("/sdcard/");
        ArrayAdapter<String> adapter
                = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1,
                filesinfolder);

        lv.setAdapter(adapter);


    }


}


@Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                ArrayList<String> filesinfolder = GetFiles("/sdcard/");
                ArrayAdapter<String> adapter
                        = new ArrayAdapter<String>(this,
                        android.R.layout.simple_list_item_1,
                        filesinfolder);

                lv.setAdapter(adapter);

            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }

        // other 'case' lines to check for other
        // permissions this app might request
    }
}


public ArrayList<String> GetFiles(String directorypath) {
    ArrayList<String> Myfiles = new ArrayList<String>();
    File f = new File(directorypath);
    f.mkdirs();
    File[] files = f.listFiles();
    if (files.length == 0) {
        return null;
    } else {
        for (int i = 0; i < files.length; i++)
            Myfiles.add(files[i].getName());
    }
    return Myfiles;
}

}

如何在列表视图中显示内部存储文件？

1 个答案: