由于权限被拒绝，MediaScannerConnection 在 Android 6 上失败

Question

我使用 MediaScannerConnection 来调用它的 scanFile 方法，用于将图像添加到设备库。但在 Android 6 中，当我执行它时会收到此异常：

E/DatabaseUtils: java.lang.SecurityException: Permission Denial: 阅读 com.android.providers.media.MediaProvider uri content://media/external/fs_id from pid=22984, uid=10078 需要 android.permission.READ_EXTERNAL_STORAGE，或grantUriPermission()

和

E/iu.UploadsManager：java.lang.SecurityException：权限拒绝： 阅读 com.android.providers.media.MediaProvider uri content://media/external/fs_id from pid=22984, uid=10078 需要 android.permission.READ_EXTERNAL_STORAGE，或grantUriPermission()

有什么帮助吗？

Answer 1

这是处理权限的新方法的结果。您的应用现在需要请求运行时许可并准备好被拒绝。

在您的 onCreate（或任何地方）中检查并可能请求许可：

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

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

            // Show an expanation to the user *asynchronously* -- don't block
            // this thread waiting for the user's response! After the user
            // sees the explanation, try again to request the permission.

        } else {

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

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

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

然后准备好接受这样的权限：

@Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_READ_MEDIA: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            } else {
                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }
    }
}