Helcio Macedo Helcio Macedo - 1 year ago 368
Android Question

android - Enable and Disable MenuItem on Navigation Drawer Activity Layout

I have and app created using the Navigation Drawer

Activity
Layout.. And I need to enable/disable some items programmatically

Menu Example

Example: I want to disable the Menu Item id nav_item2

I tried to do...

MenuItem nav_item2 = (MenuItem)findViewById(R.id.nav_item2);
nav_item2.setEnabled(false);


And it return a NullPointerException to me..

Also tried...

@Override
public boolean onPrepareOptionsMenu(Menu menu) {
super.onPrepareOptionsMenu(menu);
nav_item2 = menu.findItem(R.id.nav_item2);
return true;
}


with the same NullPointerException

Someone know something to do?

nav_header_main_activity.xml (Generated with the Layout Creation)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="@dimen/nav_header_height"
android:background="@drawable/side_nav_bar"
android:gravity="bottom"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:theme="@style/ThemeOverlay.AppCompat.Dark">

<ImageView
android:id="@+id/imageView"
android:layout_width="199dp"
android:layout_height="72dp"
android:paddingTop="@dimen/nav_header_vertical_spacing"
android:src="@drawable/ciag" />

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="@dimen/nav_header_vertical_spacing"
android:text="CIAg"
android:textAppearance="@style/TextAppearance.AppCompat.Body1" />

<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="[email protected]" />

</LinearLayout>


main_activity_navigation_drawer.xml (generated on the layout creation)




<group android:checkableBehavior="single">
<item
android:id="@+id/nav_save"
android:icon="@android:drawable/ic_menu_save"
android:enabled="false"
android:title="@string/nav_save" />
<item
android:id="@+id/nav_graph"
android:icon="@drawable/chart_bar"
android:enabled="false"
android:title="@string/nav_graph" />
<item
android:id="@+id/nav_send"
android:icon="@drawable/ic_menu_send"
android:title="Enviar" />
</group>

<item android:title="ConfiguraƧƵes">
<menu>
<item
android:id="@+id/nav_manage"
android:icon="@drawable/ic_menu_manage"
android:enabled="false"
android:title="@string/nav_manage" />
<item
android:id="@+id/nav_support"
android:icon="@android:drawable/ic_menu_help"
android:title="@string/nav_support" />
</menu>
</item>



N J N J
Answer Source

You can access menu from NavigationView.getMenu()

Below is code :

NavigationView navigationView= findViewById(R.id.nav_id_in_layout)

Menu menuNav=navigationView.getMenu();
MenuItem nav_item2 = menuNav.findItem(R.id.nav_item2);
nav_item2.setEnabled(false)
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