"First line" reading notes (a)

Section 3.6 recyclerView add dependencies

As used in the compile command build.gradle file is now no longer supported, the command to change implementation, as follows:

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'com.android.support:recyclerview-v7:24.2.1'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}

Accordingly, when reference recyclerView control the xml file, using androidx library, the following tags:

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

Section 4.4 Dynamic loading layout

Here you need to add a layout-large / activity_main.xml, but when the operation will be error: duplicate file names (although this is not the default activity_main.xml under the same path), which seems to be the new AS function, as shown below:

solution:
right-layout-large-> New-> layoutsoursefile to (the last step Do not point the xml), as shown below:

Finish