Question

我试图在RecyclerView的底部添加ProgressBar，但问题是检测到RecyclerView的底部。

我的 getItemViewType 总是返回1，因为即使我滚动到RecyclerView的底部，list.get（position）也始终不为null，这里是我的代码

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.bewerbung);

    final View thumb1View = findViewById(R.id.thumb_button_1);
    thumb1View.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            zoomImageFromThumb(thumb1View, R.drawable.anschreiben1);
        }
    });

    final View thumb2View = findViewById(R.id.thumb_button_2);
    thumb2View.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            zoomImageFromThumb(thumb2View, R.drawable.anschreiben2);
        }
    });

    mShortAnimationDuration = getResources().getInteger(
            android.R.integer.config_shortAnimTime);
}

private void zoomImageFromThumb(final View thumbView, int imageResId) {

    if (mCurrentAnimator != null) {
        mCurrentAnimator.cancel();
    }
    final ImageView expandedImageView = (ImageView) findViewById(
            R.id.expanded_image);
    expandedImageView.setImageResource(imageResId);

    final Rect startBounds = new Rect();
    final Rect finalBounds = new Rect();
    final Point globalOffset = new Point();

    thumbView.getGlobalVisibleRect(startBounds);
    findViewById(R.id.container)
            .getGlobalVisibleRect(finalBounds, globalOffset);
    startBounds.offset(-globalOffset.x, -globalOffset.y);
    finalBounds.offset(-globalOffset.x, -globalOffset.y);

    float startScale;
    if ((float) finalBounds.width() / finalBounds.height()
            > (float) startBounds.width() / startBounds.height()) {

        startScale = (float) startBounds.height() / finalBounds.height();
        float startWidth = startScale * finalBounds.width();
        float deltaWidth = (startWidth - startBounds.width()) / 2;
        startBounds.left -= deltaWidth;
        startBounds.right += deltaWidth;
    } else {

        startScale = (float) startBounds.width() / finalBounds.width();
        float startHeight = startScale * finalBounds.height();
        float deltaHeight = (startHeight - startBounds.height()) / 2;
        startBounds.top -= deltaHeight;
        startBounds.bottom += deltaHeight;
    }


    thumbView.setAlpha(0f);
    expandedImageView.setVisibility(View.VISIBLE);


    expandedImageView.setPivotX(0f);
    expandedImageView.setPivotY(0f);



    AnimatorSet set = new AnimatorSet();
    set
            .play(ObjectAnimator.ofFloat(expandedImageView, View.X,
                    startBounds.left, finalBounds.left))
            .with(ObjectAnimator.ofFloat(expandedImageView, View.Y,
                    startBounds.top, finalBounds.top))
            .with(ObjectAnimator.ofFloat(expandedImageView, View.SCALE_X,
                    startScale, 1f)).with(ObjectAnimator.ofFloat(expandedImageView,
            View.SCALE_Y, startScale, 1f));
    set.setDuration(mShortAnimationDuration);
    set.setInterpolator(new DecelerateInterpolator());
    set.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
            mCurrentAnimator = null;
        }

        @Override
        public void onAnimationCancel(Animator animation) {
            mCurrentAnimator = null;
        }
    });
    set.start();
    mCurrentAnimator = set;


    final float startScaleFinal = startScale;
    expandedImageView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (mCurrentAnimator != null) {
                mCurrentAnimator.cancel();
            }


            AnimatorSet set = new AnimatorSet();
            set.play(ObjectAnimator
                    .ofFloat(expandedImageView, View.X, startBounds.left))
                    .with(ObjectAnimator
                            .ofFloat(expandedImageView,
                                    View.Y, startBounds.top))
                    .with(ObjectAnimator
                            .ofFloat(expandedImageView,
                                    View.SCALE_X, startScaleFinal))
                    .with(ObjectAnimator
                            .ofFloat(expandedImageView,
                                    View.SCALE_Y, startScaleFinal));
            set.setDuration(mShortAnimationDuration);
            set.setInterpolator(new DecelerateInterpolator());
            set.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    thumbView.setAlpha(1f);
                    expandedImageView.setVisibility(View.GONE);
                    mCurrentAnimator = null;
                }

                @Override
                public void onAnimationCancel(Animator animation) {
                    thumbView.setAlpha(1f);
                    expandedImageView.setVisibility(View.GONE);
                    mCurrentAnimator = null;
                }
            });
            set.start();
            mCurrentAnimator = set;
        }
    });
}

任何人都可以在这里指出问题吗？

Answer 1

您使用

调整覆盖getItemCount方法

Private Sub Ctl1_Auditory_Perception_NotInList (NewData As String, Response As Integer)
    Dim strSql     As String
    If MsgBox(NewData & " not in list, add?", vbYesNo + vbQuestion) = vbYes Then
        strSql = "insert into tblEOY assessments(1 Auditory Perception) values(" & NewData & ")"
        CurrentDb.Execute strSql
        Response = acDataErrAdded

并替换

return list.size() + 1;

带

return list.get(position) != null ? 1 : 0;

然后你应该在 onCreateViewHolder 方法中检查viewType（0是你的单元格，1是加载一个）并使用正确的ViewHolder（例如，参考this link）。

还有一种更好的方法可以使用布尔值来跟踪是否有其他数据可用于防止在最后一页数据上传时显示加载单元格：

return (list.size() == position) ? 1 : 0;

Android：RecyclerView添加底部ProgressBar

1 个答案: