Custom Fonts with Support Library is not working on a real device

Question

I have used custom font with Support Library API 26. I have created font-family using style and add style to my text view. I found that font is going to set in Preview during design, but not working in android real devices. Below is my code and I have also attached screenshot. Thanks in advance.

TextView:

<TextView     android:id="@+id/card_number_text"     android:layout_width="0dp"     android:layout_height="wrap_content"     android:text="111 5235 5563 8845"     android:gravity="left"     android:layout_marginRight="8dp"     app:layout_constraintRight_toRightOf="parent"     android:layout_marginTop="8dp"     style="@style/creditCardText"     app:layout_constraintTop_toBottomOf="@+id/payableLayout"     app:layout_constraintLeft_toLeftOf="@+id/payableLayout"     app:layout_constraintHorizontal_bias="0.0" /> 

Style.xml:

<style name="creditCardText">     <item name="android:textSize">@dimen/textSizeLarge</item>     <item name="android:fontFamily">@font/font_roboto_medium</item>     <item name="android:textColor">@color/color_card_number</item> </style> 

Font Family:

<font-family xmlns:android="http://schemas.android.com/apk/res/android"> <font     android:fontStyle="normal"     android:fontWeight="400"     android:font="@font/roboto_medium" /> 

build.gradle:

apply plugin: 'com.android.application' buildscript {     repositories {     }     dependencies {    } }  android {     signingConfigs {     }    compileSdkVersion 26    defaultConfig {         applicationId "org.saifintex.skypaytrans"         minSdkVersion 18         targetSdkVersion 26         vectorDrawables.useSupportLibrary = true         versionCode 7         multiDexEnabled true         versionName "1.6"         testInstrumentationRunner          "android.support.test.runner.AndroidJUnitRunner"         externalNativeBuild {             cmake {                 cppFlags ""             }         }    }  lintOptions {     abortOnError false        // true by default     checkAllWarnings false     checkReleaseBuilds false     ignoreWarnings true       // false by default     quiet true                // false by default }  repositories {     maven { url "https://jitpack.io" } } dexOptions {     javaMaxHeapSize "4g" } buildTypes {     release {         minifyEnabled false         proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'     }     debug {         minifyEnabled false         proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'      } } externalNativeBuild {     cmake {         path "CMakeLists.txt"     } } packagingOptions {     exclude 'META-INF/DEPENDENCIES'     exclude 'META-INF/NOTICE'     exclude 'META-INF/LICENSE'     exclude 'META-INF/LICENSE.txt'     exclude 'META-INF/NOTICE.txt' } productFlavors { } sourceSets {     main {         assets.srcDirs = ['src/main/assets', 'src/main/assets/']         java.srcDirs = ['src/main/java', 'src/main/java/fonts']     }   } }  dependencies { compile fileTree(include: ['*.jar'], dir: 'libs')  androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2',  {     exclude group: 'com.android.support', module: 'support-annotations' }) compile "com.android.support:appcompat-v7:26.1.0" compile "com.android.support:design:26.1.0" compile "com.android.support:recyclerview-v7:26.1.0" compile project(':tooltip') compile project(':mylibrary') compile fileTree(include: ['*.jar'], dir: 'libs') compile "com.j256.ormlite:ormlite- android:${rootProject.ormliteAndroidVersion}" compile "com.j256.ormlite:ormlite-core:${rootProject.ormliteCoreVersion}" testCompile 'junit:junit:4.12' compile 'com.afollestad.material-dialogs:core:0.9.4.2' compile 'com.fasterxml.jackson.core:jackson-core:2.7.2' compile 'com.fasterxml.jackson.core:jackson-annotations:2.7.2' compile 'com.fasterxml.jackson.core:jackson-databind:2.7.2' compile 'com.soundcloud.android:android-crop:1.0.1@aar' compile 'com.jakewharton:butterknife:7.0.1' compile 'com.android.volley:volley:1.0.0' compile 'commons-codec:commons-codec:1.10' compile 'com.android.support:design:26.1.0' compile 'com.squareup.picasso:picasso:2.4.0' compile 'com.google.firebase:firebase-messaging:11.0.1' compile 'com.google.firebase:firebase-core:11.0.1' compile 'com.android.support:cardview-v7:26.1.0' compile 'com.android.support:support-v4:26.1.0' compile 'com.wang.avi:library:2.1.3' compile 'com.github.ayalma:ExpandableRecyclerView:0.2.0' compile 'com.github.deano2390:MaterialShowcaseView:1.1.0' compile 'com.android.support.constraint:constraint-layout:1.0.2' compile 'com.google.firebase:firebase-crash:11.0.1' compile 'com.google.firebase:firebase-auth:11.0.1' compile 'com.google.android.gms:play-services-analytics:11.0.1' compile 'com.alimuzaffar.lib:pinentryedittext:1.3.1' androidTestImplementation 'com.android.support.test:runner:1.0.1' androidTestImplementation 'com.android.support.test.espresso:espresso- core:3.0.1' testCompile 'junit:junit:4.12' }  configurations.all { resolutionStrategy.eachDependency { DependencyResolveDetails details ->     def requested = details.requested     if (requested.group == 'com.android.support') {         if (!requested.name.startsWith("multidex") &&          !requested.name.startsWith("crash")) {             details.useVersion '25.3.1'         }     } } }  apply plugin: 'com.google.gms.google-services' 

Font resource dir:

Design preview: Here font is working

Android Device Screenshot: Here font is not working

Answer 1

Change your TextView to an android.support.v7.widget.AppCompatTextView.

See https://stackoverflow.com/a/45208134/332798