Question: I'm looking for changing the **TextView** Sizes automatically. And I found the solution as well. Here is the official [Doc](https://developer.android.com/preview/features/autosizing-textview.html) for Auto sizing textviews. But Still I'm not able to resolve it. When i paste autoSizeTextType its showing error in xml file.

Here is the my xml code and gradle code snippets

myactivity.xml

```
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white"
    android:orientation="vertical">

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

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:autoSizeTextType="uniform"/>

</LinearLayout>

```

Gradle snippet

```
dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:support-v4:25.2.0'//Added support library
    compile 'com.android.support:appcompat-v7:25.2.0'
    compile 'com.android.support:design:25.2.0'
    testCompile 'junit:junit:4.12'
}

```

Answer: 
Use AppCompatTextView and supportLibrary 26.0.1

```
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.AppCompatTextView
       android:layout_width="match_parent"
       android:layout_height="200dp"
       app:autoSizeTextType="uniform" />

</LinearLayout>

```
This API is available only from API level 26.