Question

当用户开始在列表视图中向下滚动时，我尝试添加一个relativelayout。当用户滚动到顶部并显示列表视图的第一项时，我想再次显示relativelayout。

我的代码有效，但有一点＆＃34;攀登＆＃34;当用户尝试滚动时我认为问题出在listAtTop函数上，但我不知道在哪里。

enter image description here

list.setOnDetectScrollListener(new OnDetectScrollListener() {
                @Override
                public void onUpScrolling() {
                    /* do something */
                    Log.d("INFO", "UPPPPPPPPPPP");
                    if (listIsAtTop()) {
                        RelativeLayout relative1 = (RelativeLayout) findViewById(R.id.relative1);
                        relative1.setVisibility(View.VISIBLE);
                    }
                }

                @Override
                public void onDownScrolling() {
                    /* do something */
                    Log.d("INFO", "DOWNNNNNNNN");
                    if (!listIsAtTop()) {
                        RelativeLayout relative1 = (RelativeLayout) findViewById(R.id.relative1);
                        relative1.setVisibility(View.GONE);
                    }

                }
            });


private boolean listIsAtTop()   {   
        if (list.getChildCount() == 0) {
            return true;
        }
        return list.getFirstVisiblePosition() == 0 && (list.getChildCount() == 0 || list.getChildAt(0).getTop() == 0);
    }

Answer 1

试试这种方式

 list.setOnScrollListener(new OnScrollListener() {

        @Override
        public void onScroll(AbsListView view, int firstVisibleItem,
                int visibleItemCount, int totalItemCount) {
            }
        int mPosition=0;
        int mOffset=0;

        @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {
            // TODO Auto-generated method stub
             int position = list.getFirstVisiblePosition();
               View v = list.getChildAt(0);
                int offset = (v == null) ? 0 : v.getTop();

                if (mPosition < position || (mPosition == position && mOffset < offset)){
                     // Scrolled up 
                     //search_layout.setVisibility(View.GONE);

                } else {
                     // Scrolled down
                     //search_layout.setVisibility(View.VISIBLE);

                }
        }
    });

在此代码中滚动down隐藏布局时以及向上滚动并到达top然后可见布局

Android：在列表视图上向下滚动时隐藏relativelayout

1 个答案: