Question

根据https://developer.android.com/training/material/animations.html

使用ViewAnimationUtils.createCircularReveal()方法动画剪裁圆圈以显示或隐藏视图。

使用此效果显示以前不可见的视图：

// previously invisible view
View myView = findViewById(R.id.my_view);

// get the center for the clipping circle
int cx = (myView.getLeft() + myView.getRight()) / 2;
int cy = (myView.getTop() + myView.getBottom()) / 2;

// get the final radius for the clipping circle
int finalRadius = Math.max(myView.getWidth(), myView.getHeight());

// create the animator for this view (the start radius is zero)
Animator anim =
    ViewAnimationUtils.createCircularReveal(myView, cx, cy, 0, finalRadius);

// make the view visible and start the animation
myView.setVisibility(View.VISIBLE);
anim.start();

这是为了揭示一个观点。如何使用它循环显示整个活动，没有任何共享元素？

具体来说，我希望我的searchActivity从工具栏中的搜索操作按钮循环显示。

Answer 1

要反转CircularReveal动画交换startRadius和endRadius参数。此外，您还需要设置AnimatorListener，并在onAnimationEnd()回调方法中调用finishAfterTransition()。这适用于您按up navigation或点击back button。

时的情况

Answer 2

我认为您可以使用ActivityOptionsCompat.makeClipRevealAnimation。

[https://developer.android.com/reference/android/support/v4/app/ActivityOptionsCompat.html#makeClipRevealAnimation(android.view.View，int，int，int，int）]（https://developer.android.com/reference/android/support/v4/app/ActivityOptionsCompat.html#makeClipRevealAnimation(android.view.View，int，int，int，int））

Answer 3

如果要在离开活动时反转循环显示，请对onBackPressed（）使用以下修改。

@Override
public void onBackPressed() {

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        int cx = rootLayout.getWidth();
        int cy = 0;
        float finalRadius = Math.max(rootLayout.getWidth(), rootLayout.getHeight());
        Animator circularReveal = ViewAnimationUtils.createCircularReveal(rootLayout, cx, cy, finalRadius, 0);

        circularReveal.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animator) {

            }

            @Override
            public void onAnimationEnd(Animator animator) {
                rootLayout.setVisibility(View.INVISIBLE);
                finish();
            }

            @Override
            public void onAnimationCancel(Animator animator) {

            }

            @Override
            public void onAnimationRepeat(Animator animator) {

            }
        });
        circularReveal.setDuration(400);
        circularReveal.start();
    }else{
        super.onBackPressed();
    }
}

Answer 4

你必须绘制圆形视图，然后你应该为它创建一个动画。

创建圆圈视图：

public class Circle extends View {

    private static final int START_ANGLE_POINT = 90;

    private final Paint paint;
    private final RectF rect;

    private float angle;

    public Circle(Context context, AttributeSet attrs) {
        super(context, attrs);

        final int strokeWidth = 40;

        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(strokeWidth);
        //Circle color
        paint.setColor(Color.RED);

        //size 200x200 example
        rect = new RectF(strokeWidth, strokeWidth, 200 + strokeWidth, 200 + strokeWidth);

        //Initial Angle (optional, it can be zero)
        angle = 120;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawArc(rect, START_ANGLE_POINT, angle, false, paint);
    }

    public float getAngle() {
        return angle;
    }

    public void setAngle(float angle) {
        this.angle = angle;
    }
}

创建动画类以设置新角度：

public class CircleAngleAnimation extends Animation {

    private Circle circle;

    private float oldAngle;
    private float newAngle;

    public CircleAngleAnimation(Circle circle, int newAngle) {
        this.oldAngle = circle.getAngle();
        this.newAngle = newAngle;
        this.circle = circle;
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation transformation) {
        float angle = oldAngle + ((newAngle - oldAngle) * interpolatedTime);

        circle.setAngle(angle);
        circle.requestLayout();
    }
}

将圆圈放入布局：

<com.package.Circle
    android:id="@+id/circle"
    android:layout_width="300dp"
    android:layout_height="300dp" />

最后开始动画：

Circle circle = (Circle) findViewById(R.id.circle);

CircleAngleAnimation animation = new CircleAngleAnimation(circle, 240);
animation.setDuration(1000);
circle.startAnimation(animation);

通告揭示了新活动的过渡

4 个答案: