Android：适配器的getView（）有时不会被调用

Question

我的应用程序有一个充满图片的网格视图（卡片记忆游戏）。触摸后，翻转卡片并显示面部图片。但有时脸部图片不会出现。如果我再用卡片翻转，它就会恢复。

点击后我拨打1/2翻转动画：

this.gridview.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
                actPosition = position;
                cardsTurned++;
                gridview.setEnabled(false); // prevents clicking on other cards when one is actually animated

                // first part of card turn animation
                ((ImageView) gridview.getChildAt(actPosition)).clearAnimation();
                ((ImageView) gridview.getChildAt(actPosition)).setAnimation(animation1);
                ((ImageView) gridview.getChildAt(actPosition)).startAnimation(animation1);
            }
        });

在动画结束后，我将位图设置到正确的位置：

    @Override
public void onAnimationEnd(Animation animation) {
    Bitmap bitmapFace = BitmapFactory.decodeFile(this.imageAdapter.getItem(actPosition).getBitmapFace());
    Bitmap bitmapBack = BitmapFactory.decodeResource(getResources(), R.drawable.card_back);

    // after animation1 should come animation2
    if (animation==animation1) {
        // now we see nothing, change picture to face/back
        if (imageAdapter.getItem(actPosition).getBackShowed())  // if we see back
            ((ImageView) gridview.getChildAt(actPosition)).setImageBitmap(bitmapFace);  // show face
        else    // if we see face
            ((ImageView) gridview.getChildAt(actPosition)).setImageBitmap(bitmapBack);  // show back 

        // complete animation with the second part and show changed picture
        ((ImageView) gridview.getChildAt(actPosition)).clearAnimation();
        ((ImageView) gridview.getChildAt(actPosition)).setAnimation(animation2);
        ((ImageView) gridview.getChildAt(actPosition)).startAnimation(animation2);
    }
    else {
        if(this.cardsTurned == 1) { // 1 card is turned now
            card1 = imageAdapter.getItem(actPosition);  // first turned card
            gridview.getChildAt(actPosition).setClickable(true);    // wait for the second card
        }
        else if(this.cardsTurned == 2) {    // 2 cards are turned now
            card2 = imageAdapter.getItem(actPosition);  // second turned card

            // if cards are a PAIR, remove them from gridview
            if(card1.getPair() == actPosition) {    // turned cards are a PAIR
                // remove cards
                gridview.getChildAt(card1.getPosition()).setAlpha(0);
                gridview.getChildAt(card1.getPosition()).setOnClickListener(null);
                gridview.getChildAt(actPosition).setAlpha(0);
                gridview.getChildAt(actPosition).setOnClickListener(null);
            }
            else {  // cards are not a PAIR
                // card2 turn back
                ((ImageView) gridview.getChildAt(actPosition)).clearAnimation();
                ((ImageView) gridview.getChildAt(actPosition)).setAnimation(animation1);
                ((ImageView) gridview.getChildAt(actPosition)).startAnimation(animation1);

                ((ImageView) gridview.getChildAt(actPosition)).setImageBitmap(bitmapBack);

                ((ImageView) gridview.getChildAt(actPosition)).clearAnimation();
                ((ImageView) gridview.getChildAt(actPosition)).setAnimation(animation2);
                ((ImageView) gridview.getChildAt(actPosition)).startAnimation(animation2);

                // card1 turn back
                ((ImageView) gridview.getChildAt(card1.getPosition())).clearAnimation();
                ((ImageView) gridview.getChildAt(card1.getPosition())).setAnimation(animation1);
                ((ImageView) gridview.getChildAt(card1.getPosition())).startAnimation(animation1);

                ((ImageView) gridview.getChildAt(card1.getPosition())).setImageBitmap(bitmapBack);

                ((ImageView) gridview.getChildAt(card1.getPosition())).clearAnimation();
                ((ImageView) gridview.getChildAt(card1.getPosition())).setAnimation(animation2);
                ((ImageView) gridview.getChildAt(card1.getPosition())).startAnimation(animation2);
                imageAdapter.getItem(card1.getPosition()).changeBackShowed();
                gridview.getChildAt(card1.getPosition()).setClickable(false);
            }

            this.cardsTurned = 0;
        }

        // unlock grid view for another clicking
        imageAdapter.getItem(actPosition).changeBackShowed();
        gridview.setEnabled(true);
    }
}

我的适配器的getCount（）总是返回20：

@Override
    public int getCount() {
        Log.d(TAG, "getCount(): " + cards.length);
        return cards.length;
    }

当图片未显示时，也不会调用适配器的getView（）。

怎么可能？是GridView还是我做错了什么？