Question

准确地说，我正在努力将视图放到列表中，当用户放下视图时，它应该以曲线路径进入listview中的列表。

PS：我看过很多动画，但是沿着x坐标，而不是沿着y坐标。感谢您的所有帮助。

我使用过ArcTranslate类 Problem to achieve curved animation 但那是沿x坐标的曲线。

弧动画的代码：

    public class ArcAnimation extends Animation {

private Point start;
private Point end;
private Point middle;
private final float mFromXValue;
private final float mToXValue;
private final float mYValue;
private final int mFromXType;
private final int mToXType;
private final int mYType;

/**
 * A translation along an arc defined by three points and a Bezier Curve
 *
 * @param duration - the time in ms it will take for the translation to complete
 * @param fromXType - One of Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or Animation.RELATIVE_TO_PARENT.
 * @param fromXValue - Change in X coordinate to apply at the start of the animation
 * @param toXType - One of Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or Animation.RELATIVE_TO_PARENT.
 * @param toXValue - Change in X coordinate to apply at the end of the animation
 * @param yType - One of Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or Animation.RELATIVE_TO_PARENT.
 * @param yValue - Change in Y coordinate to apply at the middle of the animation (the radius of the arc)
 */
public ArcAnimation(long duration, int fromXType, float fromXValue,
        int toXType, float toXValue, int yType, float yValue){
    setDuration(duration);

     mFromXValue = fromXValue;
     mToXValue = toXValue;
     mYValue = yValue;

     mFromXType = fromXType;
     mToXType = toXType;
     mYType = yType;

}

/** Calculate the position on a quadratic bezier curve given three points
 *  and the percentage of time passed.
 * from http://en.wikipedia.org/wiki/B%C3%A9zier_curve
 * @param interpolatedTime - the fraction of the duration that has passed where 0<=time<=1
 * @param p0 - a single dimension of the starting point
 * @param p1 - a single dimension of the middle point
 * @param p2 - a single dimension of the ending point
 */
private long calcBezier(float interpolatedTime, float p0, float p1, float p2){
    return Math.round((Math.pow((1 - interpolatedTime), 2) * p0)
           + (2 * (1 - interpolatedTime) * interpolatedTime * p1)
           + (Math.pow(interpolatedTime, 2) * p2));
}

@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
    float dx = calcBezier(interpolatedTime, start.x, middle.x, end.x);
    float dy = calcBezier(interpolatedTime, start.y, middle.y, end.y);

    t.getMatrix().setTranslate(dy, dx);
}

@Override
public void initialize(int width, int height, int parentWidth, int parentHeight) {
    super.initialize(width, height, parentWidth, parentHeight);
    float startX = resolveSize(mFromXType, mFromXValue, height, parentHeight);
    float endX = resolveSize(mToXType, mToXValue, height, parentHeight);
    float middleY = resolveSize(mYType, mYValue, height, parentHeight);
    float middleX = startX + ((endX-startX)/2);
    start = new Point((int)startX, 0);
    end = new Point((int)endX, 0);
    middle = new Point((int)middleX, (int)middleY);
}
}

使用以下代码，对象直接进入列表，但不是以曲线方式。如何使弧形动画工作？

谢谢！

android中沿y坐标的曲线动画

0 个答案: