安卓View設置VISIBLE、GONE時，添加執行動畫

我們在開發中經常要實現view的可見性的設置，但是如果view面積較大時可見性如果變化，在視覺效果上會比較生硬，因此我們需要加上動畫，在可見不可見之間增加一個過渡

直接上代碼：

if (view.getVisibility() == View.VISIBLE) {
    TranslateAnimation hideAnim = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0.0f,
            Animation.RELATIVE_TO_SELF, 0.0f, Animation.RELATIVE_TO_SELF, 0.0f, Animation.RELATIVE_TO_SELF, 1.0f);
    hideAnim.setDuration(500);
    view.startAnimation(hideAnim);
    hideAnim.setAnimationListener(new Animation.AnimationListener() {
        @Override
        public void onAnimationStart(Animation animation) {

        }

        @Override
        public void onAnimationEnd(Animation animation) {
            llShiftClass.setVisibility(View.GONE);
        }

        @Override
        public void onAnimationRepeat(Animation animation) {

        }
    });
} else {
    TranslateAnimation showAnim = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0.0f,
            Animation.RELATIVE_TO_SELF, 0.0f, Animation.RELATIVE_TO_SELF, 1.0f, Animation.RELATIVE_TO_SELF, 0.0f);
    showAnim.setDuration(500);
    view.startAnimation(showAnim);
    view.setVisibility(View.VISIBLE);
}
這裏，最重要的是TranslateAnimation，進入這個構造函數：

 

/**
     * 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，這個構造函數主要是傳入設置起始點座標(x,y)、終點座標(x,y)，每個座標值對應一個類型type。

Animation.RELATIVE_TO_SELF代表着座標以當前view爲基準。

0.0f即0%，代表view初始位置座標；

1.0f即100%，代表以view初始位置爲原點，相應x座標/y座標增加父寬度/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);

表示從（1.0f,0.0f）移動到（0.0f,0.0f），即view從屏幕右側不可見區域移動到初始位置，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);
 

表示從（0.0f,0.0f）移動到（1.0f,0.0f），即view從初始位置移動到屏幕右側不可見區域，符合GONE效果。