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