how to make toolbar stays on top-CodePudding

i have my toolbar set as transparent background, i want it to stay on top of image. i tried use Framelayout yet still same. how do i set my toolbar always on top? But I can't make my Activity be on top and be visible at the back of my ToolBar...

my Image

my xml

`<LinearLayout 
    <androidx.appcompat.widget.Toolbar
        android:id="@ id/tool_bar"
        android:background="@android:color/transparent"
        android:backgroundTint="@android:color/transparent"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="C I N E M A"
            android:textColor="@color/white"
            android:textSize="24sp"
            android:layout_gravity="center"
            android:id="@ id/toolbar_title" />
    </androidx.appcompat.widget.Toolbar>
    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        >
        <com.denzcoskun.imageslider.ImageSlider
            android:id="@ id/image_slider"
            android:layout_width="wrap_content"
            android:layout_height="500dp"/>
    </androidx.constraintlayout.widget.ConstraintLayout>

</LinearLayout>`

CodePudding user response：

In the activity's onCreate() method, call the activity's setSupportActionBar() method, and pass the activity's toolbar. This method sets the toolbar as the app bar for the activity. For example:

For Kotlin;

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_my)
    // Note that the Toolbar defined in the layout has the id "my_toolbar"
    setSupportActionBar(findViewById(R.id.my_toolbar))
}

For Java;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);
    Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
    setSupportActionBar(myToolbar);
}

and You can use elevation.

your toolbar wrap layout : android:elevation="4dp"

sample ;

<com.google.android.material.appbar.MaterialToolbar
     app:elevation="8dp"
     android:elevation="8dp"
     android:background="@color/white"/>