How to hide ToolBar when I scrolling content up?

you have to do many changes in your both layout. first use CoordinatorLayout in activity_main.XML like below(change theme as per your requirement).

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

</android.support.design.widget.CoordinatorLayout>

in content_main.XML use android.support.v4.widget.NestedScrollView instead of ScrollView.

also use app:layout_behavior="@string/appbar_scrolling_view_behavior" inside android.support.v4.widget.NestedScrollView like below.

<android.support.v4.widget.NestedScrollView
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:android="http://schemas.android.com/apk/res/android" 
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <TextView
                android:id="@+id/textone"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:text="hello world jheds sdjhs jds sjbs skjs ksjs kksjs ksj sdd dskd js sk "
                android:textSize="25dp"
                android:textStyle="bold" />

            /// Add your other code here

            </LinearLayout>

    </android.support.v4.widget.NestedScrollView>