这是我的代码
<?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"
android:background="@color/nav_and_action_bar_color"
>
<ImageView
android:id="@+id/some_person"
android:layout_width="100dp"
android:layout_height="100dp"
android:src="@drawable/some_person"
app:layout_constraintBottom_toTopOf="@+id/et_username"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<EditText
android:id="@+id/et_username"
android:layout_width="@dimen/login_page_text_fields_width"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:background="@android:color/white"
android:hint="@string/email_hint"
android:padding="10dp"
app:layout_constraintBottom_toTopOf="@+id/et_password"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/some_person" />
<EditText
android:id="@+id/et_password"
android:layout_width="@dimen/login_page_text_fields_width"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:background="@android:color/white"
android:hint="@string/password_hint"
android:inputType="textPassword"
android:padding="10dp"
app:layout_constraintBottom_toTopOf="@+id/login_button"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@id/et_username" />
<Button
android:id="@+id/login_button"
android:layout_width="@dimen/login_button_width"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:background="@color/colorAccent"
android:elevation="5dp"
android:onClick="clickedOnLogin"
android:text="@string/login_button"
android:textColor="@android:color/white"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@id/et_password" />
</android.support.constraint.ConstraintLayout>
结果我似乎得到了这个
我如何将元素组合在一起?我希望他们靠得很近。