Load from Image from XML to ImageView

I want to load an image from an XML file tag <image> to the ImageView.

The layout file:

<LinearLayout xmlns:android="http://ift.tt/nIICcg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:clickable="false">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/projectImage" />

        <TextView xmlns:android="http://ift.tt/nIICcg"
            android:id="@+id/jobtitle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="10dip"
            android:textSize="14sp"
            android:textStyle="bold"
            android:text="jobtitle">
        </TextView>

        <TextView xmlns:android="http://ift.tt/nIICcg"
            android:id="@+id/jobinfo"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:textSize="11sp"
            android:textStyle="normal"
            android:text="jobinfo"
            android:paddingLeft="10dp">
        </TextView>

    </LinearLayout>

</LinearLayout>

At this point i look up if the file already exists, if not, then download and parse it.

File file = new File(this.getFilesDir(), "Arbeitsauftrag_Bootsbau_Meier_vom_20150216.kx_job");
        if (file.exists()) {

            XMLParser parser = new XMLParser();
            Document doc = parser.getDomElement(readFromFile("Arbeitsauftrag_Bootsbau_Meier_vom_20150216.kx_job"));

            NodeList nodeListProject = doc.getElementsByTagName(KEY_PROJECT);
            NodeList nodeListTasks = doc.getElementsByTagName(KEY_TASK);

            //Schleife für Aufgaben
            for (int i = 0; i < nodeListTasks.getLength(); i++) {
                HashMap<String, String> map = new HashMap<>();
                Element e = (Element) nodeListTasks.item(i);

                map.put(KEY_UUID_OBJ, parser.getValue(e, KEY_UUID_OBJ));
                map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
                map.put(KEY_INFO, parser.getValue(e, KEY_INFO));
                map.put(KEY_OBJECT, parser.getValue(e, KEY_OBJECT));
                map.put(KEY_LOCATION, parser.getValue(e, KEY_LOCATION));
                map.put(KEY_OBJECT_ID, parser.getValue(e, KEY_OBJECT_ID));
                map.put(KEY_OBJECT_SNR, parser.getValue(e, KEY_OBJECT_SNR));
                map.put(KEY_REGISTRATION_ID, parser.getValue(e, KEY_REGISTRATION_ID));
                map.put(KEY_TASKIMAGE, parser.getValue(e, KEY_TASKIMAGE));
                map.put(KEY_TASK_HEADLINE, parser.getValue(e, KEY_TASK_HEADLINE));
                map.put(KEY_TASK_SUBJECT, parser.getValue(e, KEY_TASK_SUBJECT));
                map.put(KEY_TASK_ACTION, parser.getValue(e, KEY_TASK_ACTION));
                map.put(KEY_TASK_PRIORITY_COLOR, parser.getValue(e, KEY_TASK_PRIORITY_COLOR));
                map.put(KEY_TASK_STATUS, parser.getValue(e, KEY_TASK_STATUS));
                map.put(KEY_TASKIMAGE, parser.getValue(e,KEY_TASKIMAGE));

                taskItems.add(map);
            }

            // Schleife für Auftragsinfos
            for (int i = 0; i < nodeListProject.getLength(); i++) {

                // Neue HashMap erstellen
                HashMap<String, String> map = new HashMap<>();
                Element e = (Element) nodeListProject.item(i);

                // Jedes Kind-Knoten zur HashMap
                map.put(KEY_UUID, parser.getValue(e, KEY_UUID));
                map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
                map.put(KEY_JOBTITLE, parser.getValue(e, KEY_JOBTITLE));
                map.put(KEY_JOBINFO, parser.getValue(e, KEY_JOBINFO));


                //Hashmap zur ArrayList hinzufügen
                projectItems.add(map);
            }

            ListAdapter adapter = new SimpleAdapter(ListViewActivity.this, projectItems,
                    R.layout.list_item_projects,
                    new String[]{KEY_JOBTITLE, KEY_JOBINFO},
                    new int[]{R.id.jobtitle, R.id.jobinfo});

            setListAdapter(adapter);
            //file.delete();


        } else {
            DownloadXMLFiles dlxmlf = new DownloadXMLFiles();
            dlxmlf.execute();
        }

This method is for decoding the base64 string:

 public static Bitmap decodeBase64(String input) {
        byte[] decodedByte = Base64.decode(input, Base64.DEFAULT);
        return BitmapFactory.decodeByteArray(decodedByte, 0, decodedByte.length);
    }

My ImageView is not at the MainActivity.

I'm looking how i can put the image from Base64 to Bitmap and set it as Image on my ImageView?

P.S. my ImageView isn't in the same Layout as my setContentView.