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私はちょうどConstraint Layoutを学び始めました。とてもクールです。私はConstraintSetをトピックにして立ち往生しました。ConstraintSetはどのくらい正確にAndroidのConstraintLayoutsで動作しますか？
私はConstraintSetの例を開発者向けドキュメントに見ましたが、私はそのアイデアを得ることができません。コードをそのまま実装していますが、実際にはわかりません。
異なるConstraintSetでの制約の働きについては、私が知りたいことばかりです。ここで
は私がやっていることです：
activity_main.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"
android:id="@+id/act_main"
tools:context="com.reversebits.constraintanimdemo.MainActivity">
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:text="Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum"
app:layout_constraintEnd_toStartOf="@+id/guideline2"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="8dp" />
<ImageView
android:id="@+id/imageView"
android:layout_width="0dp"
android:layout_height="160dp"
app:srcCompat="@mipmap/ic_launcher"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="8dp"
app:layout_constraintStart_toStartOf="@+id/guideline2"
android:layout_marginStart="8dp" />
<android.support.constraint.Guideline
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/guideline"
android:orientation="vertical"
app:layout_constraintGuide_end="364dp" />
<android.support.constraint.Guideline
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/guideline2"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.5" />
<Button
android:onClick="foo"
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"/>
</android.support.constraint.ConstraintLayout>
clone.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="com.reversebits.constraintanimdemo.MainActivity">
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum"
app:layout_constraintStart_toStartOf="parent"
android:layout_marginEnd="8dp"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginStart="8dp"
android:id="@+id/textView"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="8dp" />
<ImageView
android:id="@+id/imageView"
android:layout_width="0dp"
android:layout_height="160dp"
app:srcCompat="@mipmap/ic_launcher"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp"
app:layout_constraintStart_toStartOf="parent"
android:layout_marginStart="8dp"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
app:layout_constraintTop_toBottomOf="@+id/textView" />
<Button
android:onClick="foo"
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"/>
</android.support.constraint.ConstraintLayout>
とMainActivityはここに行く：
import android.content.Context;
import android.os.Build;
import android.support.constraint.ConstraintLayout;
import android.support.constraint.ConstraintSet;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.transition.TransitionManager;
import android.view.View;
public class MainActivity extends AppCompatActivity {
ConstraintSet mConstraintSet1 = new ConstraintSet(); // create a Constraint Set
ConstraintSet mConstraintSet2 = new ConstraintSet(); // create a Constraint Set
ConstraintLayout mConstraintLayout; // cache the ConstraintLayout
boolean mOld = true;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Context context = this;
mConstraintSet2.clone(context, R.layout.clone); // get constraints from layout
setContentView(R.layout.activity_main);
mConstraintLayout = (ConstraintLayout) findViewById(R.id.act_main);
mConstraintSet1.clone(mConstraintLayout); // get constraints from ConstraintSet
}
public void foo(View view) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
TransitionManager.beginDelayedTransition(mConstraintLayout);
}
if (mOld = !mOld) {
mConstraintSet1.applyTo(mConstraintLayout); // set new constraints
} else {
mConstraintSet2.applyTo(mConstraintLayout); // set new constraints
}
}
}