安卓开发——为View设置VISIBLE、GONE时，添加执行动画

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直接上代码：

1、VISIBLE动画

TranslateAnimation showAnim = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 1.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f);
showAnim.setDuration(500);
view.startAnimation(showAnim);
view.setVisibility(View.VISIBLE);

2、GONE动画

TranslateAnimation hideAnim = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0.0f,
                    Animation.RELATIVE_TO_SELF, 1.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f);
hideAnim.setDuration(500);
view.startAnimation(hideAnim);
view.setVisibility(View.GONE);

这里，最重要的是TranslateAnimation，进入这个构造函数：

/**
     * Constructor to use when building a TranslateAnimation from code
     * 
     * @param fromXType Specifies how fromXValue should be interpreted. 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. This value can either be an absolute number if fromXType
     *        is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise.
     * @param toXType Specifies how toXValue should be interpreted. 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. This value can either be an absolute number if toXType
     *        is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise.
     * @param fromYType Specifies how fromYValue should be interpreted. One of
     *        Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or
     *        Animation.RELATIVE_TO_PARENT.
     * @param fromYValue Change in Y coordinate to apply at the start of the
     *        animation. This value can either be an absolute number if fromYType
     *        is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise.
     * @param toYType Specifies how toYValue should be interpreted. One of
     *        Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or
     *        Animation.RELATIVE_TO_PARENT.
     * @param toYValue Change in Y coordinate to apply at the end of the
     *        animation. This value can either be an absolute number if toYType
     *        is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise.
     */
    public TranslateAnimation(int fromXType, float fromXValue, int toXType, float toXValue,
            int fromYType, float fromYValue, int toYType, float toYValue) {

        mFromXValue = fromXValue;
        mToXValue = toXValue;
        mFromYValue = fromYValue;
        mToYValue = toYValue;

        mFromXType = fromXType;
        mToXType = toXType;
        mFromYType = fromYType;
        mToYType = toYType;
    }

可以看到，这个构造函数主要是传入设置起始点坐标(x,y)、终点坐标(x,y)，每个坐标值对应一个类型type。

Animation.RELATIVE_TO_SELF代表着坐标以当前view为基准。

0.0f即0%，代表view初始位置坐标；

1.0f即100%，代表以view初始位置为原点，相应x坐标/y坐标增加父宽度/父高度的100%；

TranslateAnimation showAnim = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 1.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f);

表示从（1.0f,0.0f）移动到（0.0f,0.0f），即view从屏幕右侧不可见区域移动到初始位置，符合VISIBLE效果。

new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0.0f,
                    Animation.RELATIVE_TO_SELF, 1.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f,
                    Animation.RELATIVE_TO_SELF, 0.0f);

表示从（0.0f,0.0f）移动到（1.0f,0.0f），即view从初始位置移动到屏幕右侧不可见区域，符合GONE效果。