Android 實作多個元件/控件從左側依次彈出的效果

最新有需求是一個顔色選擇，然後點選顔色選擇按鈕，依次展開供選擇的顔色按鈕，話不多說，先看效果圖

 效果圖是故意增加了進場時間的效果。

實作思路：

1.點選按鈕，然後隐藏按鈕，把要展示的布局顯示出來

2.周遊父布局RadioGroup，給每個字控件RadioButton設定進場動畫效果，以及設計一個小小的延遲。

具體如下：

1.布局檔案：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".Main3Activity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text='展開'
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"

        android:id="@+id/span"
        >

    </Button>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:animateLayoutChanges="true"
        android:id="@+id/colorselect"
        android:layout_marginStart="-30dp"
        android:visibility="gone"
        >

        <RadioGroup
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"
            android:orientation="horizontal"
            android:id="@+id/radiogroup"
            >
            <RadioButton
                android:layout_width="25dp"
                android:layout_height="25dp"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                android:id="@+id/color1"
                android:background="@drawable/color1"
                android:checked="true"
                android:button="@null"

                >

            </RadioButton>

            <RadioButton
                android:layout_width="25dp"
                android:layout_height="25dp"
                app:layout_constraintLeft_toRightOf="@+id/color1"
                app:layout_constraintTop_toTopOf="parent"
                android:id="@+id/color2"
                android:button="@null"
                android:background="@drawable/color2"
                android:layout_marginLeft="10dp"
                >

            </RadioButton>

            <RadioButton
                android:layout_width="25dp"
                android:layout_height="25dp"
                app:layout_constraintLeft_toRightOf="@id/color2"
                app:layout_constraintTop_toTopOf="parent"
                android:id="@+id/color3"
                android:button="@null"
                android:background="@drawable/color3"
                android:layout_marginLeft="10dp"
                >

            </RadioButton>

            <RadioButton
                android:layout_width="25dp"
                android:layout_height="25dp"
                app:layout_constraintLeft_toRightOf="@+id/color3"
                app:layout_constraintTop_toTopOf="parent"
                android:id="@+id/color4"
                android:background="@drawable/color4"
                android:button="@null"
                android:layout_marginLeft="10dp"
                >

            </RadioButton>

        </RadioGroup>
    </androidx.constraintlayout.widget.ConstraintLayout>


</androidx.constraintlayout.widget.ConstraintLayout>
           

2.設定動畫

public class Main3Activity extends AppCompatActivity {

    private Button span;
    private ConstraintLayout sel;
    private RadioGroup radioGroup;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        span = findViewById(R.id.span);
        sel = findViewById(R.id.colorselect);
        radioGroup = findViewById(R.id.radiogroup);


        span.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                span.setVisibility(View.GONE);
                sel.setVisibility(View.VISIBLE);
                startAnimation(radioGroup);
            }
        });
    }

    private void startAnimation(ViewGroup viewGroup) {
        Handler mHandler = new Handler();
        for (int i = 0; i < viewGroup.getChildCount(); i++) {
            final View child = viewGroup.getChildAt(i);
            child.setVisibility(View.GONE);
            mHandler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    child.setVisibility(View.VISIBLE);
                    ValueAnimator anim = ObjectAnimator.ofFloat(child, "translationX", -500, 0);
                    anim.setDuration(200);
                    anim.start();
                }
            }, i * 30);
        }
    }
}
           

大概就是這麼個流程就能實作上面的效果，看看，自己修改修改。