垂直与抛物线

绘制

public class CustomView extends View {
public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

public CustomView(Context context, AttributeSet attrs) {
    super(context, attrs);
}

public CustomView(Context context) {
    super(context);
}
//测量

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
//重写OnDraw绘制基本图形

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    //先创建画笔
    Paint paint = new Paint();
    //设置画笔颜色
    paint.setColor(Color.BLUE);
    // 设置抗锯齿
    paint.setAntiAlias(true);
    // 三种样式
    paint.setStyle(Paint.Style.FILL_AND_STROKE);
    //设置边的宽度
    paint.setStrokeWidth(5);

    // 阴影
    paint.setShadowLayer(10, 0, 0, Color.CYAN);

    //绘制圆
    canvas.drawCircle(30, 30, 15, paint);
}

}

布局

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout… 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:id="@+id/id_container"
android:layout_width=“match_parent”
android:layout_height=“match_parent”
tools:context=".activity.MainActivity">

<com.bwie.yuan.activity.CustomView
    android:id="@+id/ball"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:orientation="horizontal">

    <Button
        android:id="@+id/button01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="垂直"
        android:textSize="20sp" />

    <Button
        android:id="@+id/button02"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="抛物线"
        android:textSize="20sp" />

    <Button
        android:id="@+id/button03"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="跳转"
        android:textSize="20sp" />
</LinearLayout>

</RelativeLayout…>

主页

import com.bwie.yuan.R;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

private CustomView ball;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //找控件
    ball = findViewById(R.id.ball);

    Button button1 = findViewById(R.id.button01);
    Button button2 = findViewById(R.id.button02);


    button1.setOnClickListener(this);
    button2.setOnClickListener(this);
    findViewById(R.id.button03).setOnClickListener(this);

}

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.button01:

            ValueAnimator va1 = new ValueAnimator();
            va1.setDuration(3000);
            va1.setObjectValues(new PointF(0, 0));
            va1.setInterpolator(new LinearInterpolator());
            va1.setEvaluator(new TypeEvaluator<PointF>() {
                @Override
                public PointF evaluate(float fraction, PointF startValue, PointF endValue) {
                    PointF point = new PointF();
                    point.x = 0;
                    point.y = 0.5f * 200 * (fraction * 3) * (fraction * 3);

                    return point;
                }
            });
            va1.start();
            va1.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                @Override
                public void onAnimationUpdate(ValueAnimator animation) {
                    PointF point = (PointF) animation.getAnimatedValue();
                    ball.setX(point.x);
                    ball.setY(point.y);
                }
            });
            break;
        case R.id.button02:
            ValueAnimator va = new ValueAnimator();
            va.setDuration(3000);
            va.setObjectValues(new PointF(0, 0));
            va.setInterpolator(new LinearInterpolator());
            va.setEvaluator(new TypeEvaluator<PointF>() {
                @Override
                public PointF evaluate(float fraction, PointF startValue, PointF endValue) {
                    PointF point = new PointF();
                    point.x = 200 * fraction * 3;
                    point.y = 0.5f * 200 * (fraction * 3) * (fraction * 3);

                    return point;
                }
            });
            va.start();
            va.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                @Override
                public void onAnimationUpdate(ValueAnimator animation) {
                    PointF point = (PointF) animation.getAnimatedValue();
                    ball.setX(point.x);
                    ball.setY(point.y);
                }
            });

            break;
        case R.id.button03:
            startActivity(new Intent(MainActivity.this, ShowActivity.class));
            finish();
            break;
    }
}

}