Android 3D旋转动画效果

这篇文章主要介绍一下如何实现View的3D旋转效果，实现的主要原理就是围绕Y轴旋转，同时在Z轴方面上有一个深入的缩放。

演示的demo主要有以下几个重点：

1，自定义旋转动画

2，动画做完后，重置ImageView

先看一下程序的运行效果：

1，自定义动画类

这里实现了一个Rotate3dAnimation的类，它扩展了Animation类，重写applyTransformation()方法，提供指定时间的矩阵变换，我们在这个方法里，就可以利用Camera类得得到一个围绕Y轴旋转的matrix，把这个matrix设置到Transformation对象中。具体的实现代码如下：

[java] @Override
protected void applyTransformation(float interpolatedTime, Transformation t)
{
        final float fromDegrees = mFromDegrees;
        float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime);

        final float centerX = mCenterX;
        final float centerY = mCenterY;
        final Camera camera = mCamera;

        final Matrix matrix = t.getMatrix();

        camera.save();
        if (mReverse) {
            camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);
        } else {
            camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));
        }
        camera.rotateY(degrees);
        camera.getMatrix(matrix);
        camera.restore();

        matrix.preTranslate(-centerX, -centerY);
        matrix.postTranslate(centerX, centerY);
}

@Override
protected void applyTransformation(float interpolatedTime, Transformation t)
{
final float fromDegrees = mFromDegrees;
float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime);

        final float centerX = mCenterX;
        final float centerY = mCenterY;
        final Camera camera = mCamera;

final Matrix matrix = t.getMatrix();

        camera.save();
        if (mReverse) {
            camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);
        } else {
            camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));
        }
        camera.rotateY(degrees);
        camera.getMatrix(matrix);
        camera.restore();

matrix.preTranslate(-centerX, -centerY);
matrix.postTranslate(centerX, centerY);
}

2，如何使用这个动画类

在Activity中，我们有两个大小一样的ImageView，它们都放在FrameLayout中，这样他们位置是重叠的，对最上面的ImageView做动画（旋转角度从0到90），当动画做完后，再对后面的ImageView做动画（旋转角度从90到180），在这里，要控制相应的ImageView隐藏或显示。

动画的listener实现如下：

[java] private final class DisplayNextView implements Animation.AnimationListener {

        public void onAnimationStart(Animation animation) {
        }

        public void onAnimationEnd(Animation animation) {

            mContainer.post(new SwapViews());
        }

        public void onAnimationRepeat(Animation animation) {
        }
    }

private final class DisplayNextView implements Animation.AnimationListener {

public void onAnimationStart(Animation animation) {
}

public void onAnimationEnd(Animation animation) {

mContainer.post(new SwapViews());
}

        public void onAnimationRepeat(Animation animation) {
        }
    }

动画做完后，执行的代码如下：

[java] private final class SwapViews implements Runnable
    {
        @Override
        public void run()
        {
            mImageView1.setVisibility(View.GONE);
            mImageView2.setVisibility(View.GONE);

            mIndex++;
            if (0 == mIndex % 2)
            {
                mStartAnimView = mImageView1;
            }
            else
            {
                mStartAnimView = mImageView2;
            }

            mStartAnimView.setVisibility(View.VISIBLE);
            mStartAnimView.requestFocus();

            Rotate3dAnimation rotation = new Rotate3dAnimation(
                    -90,
                    0,
               &nb

补充：移动开发 , Android ,