YouMap/lesson03/src/main/res/layout/activity_publish.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context="io.hsiao.lesson03.PublishActivity">


    <ScrollView
        android:id="@+id/scrollView2"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:fillViewport="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/publish_toolbar">

        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <EditText
                android:id="@+id/publish_txt_title"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginEnd="8dp"
                android:layout_marginStart="8dp"
                android:layout_marginTop="8dp"
                android:ems="10"
                android:hint="标题"
                android:inputType="textPersonName"
                android:minLines="@integer/publish_desc_lines"
                android:textSize="12sp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

            <EditText
                android:id="@+id/publish_txt_desc"
                android:layout_width="0dp"
                android:layout_height="100dp"
                android:layout_marginEnd="8dp"
                android:layout_marginStart="8dp"
                android:layout_marginTop="8dp"
                android:contentDescription=" "
                android:ems="10"
                android:gravity="top"
                android:hint="简述"
                android:inputType="textMultiLine"
                android:singleLine="false"
                android:textSize="12sp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/publish_txt_title" />

            <ImageButton
                android:id="@+id/publish_choose_btn"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="8dp"
                android:layout_marginTop="8dp"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/publish_txt_desc"
                app:srcCompat="@drawable/ic_action_collections" />

            <GridView
                android:id="@+id/publish_gridview"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_marginEnd="8dp"
                android:layout_marginStart="8dp"
                android:layout_marginTop="8dp"
                android:numColumns="@integer/main_grid_column_count"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@id/publish_choose_btn" />

        </android.support.constraint.ConstraintLayout>

    </ScrollView>

    <android.support.v7.widget.Toolbar
        android:id="@+id/publish_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:title="发布照片"></android.support.v7.widget.Toolbar>

</android.support.constraint.ConstraintLayout>