安卓：隐藏的RelativeLayout时的ListView向下滚动 [英] Android : Hide relativelayout when scroll down on listview

问题描述

我尝试当用户开始在ListView向下滚动到添加RelativeLayout的。
我想再次显示的RelativeLayout当用户滚动到顶部并显示列表视图的第一个项目时。

我的code的作品，但有一点爬，当用户试图滚动。
我认为这个问题是位于listAtTop功能，但我不知道在哪里。

  list.setOnDetectScrollListener（新OnDetectScrollListener（）{
                @覆盖
                公共无效onUpScrolling（）{
                    /* 做一点事 */
                    Log.d（信息，UPPPPPPPPPPP）;
                    如果（listIsAtTop（））{
                        RelativeLayout的relative1 =（RelativeLayout的）findViewById（R.id.relative1）;
                        relative1.setVisibility（View.VISIBLE）;
                    }
                }                @覆盖
                公共无效onDownScrolling（）{
                    /* 做一点事 */
                    Log.d（信息，DOWNNNNNNNN）;
                    如果（！listIsAtTop（））{
                        RelativeLayout的relative1 =（RelativeLayout的）findViewById（R.id.relative1）;
                        relative1.setVisibility（View.GONE）;
                    }                }
            }）;
私人布尔listIsAtTop（）{
        如果（list.getChildCount（）== 0）{
            返回true;
        }
        返回list.getFirstVisiblePosition（）== 0安培;＆安培; （list.getChildCount（）== 0 || list.getChildAt（0）.getTop（）== 0）;
    }
 

解决方案

试试这个方法。

  list.setOnScrollListener（新OnScrollListener（）{        @覆盖
        公共无效onScroll（AbsListView观点，诠释firstVisibleItem，
                INT visibleItemCount，诠释totalItemCount）{
            }
        INT mPosition = 0;
        INT mOffset = 0;        @覆盖
        公共无效onScrollStateChanged（AbsListView观点，诠释scrollState）{
            // TODO自动生成方法存根
             INT位置= list.getFirstVisiblePosition（）;
               视图V = list.getChildAt（0）;
                偏移为int =（V == NULL）？ 0：v.getTop（）;                如果（mPosition＆LT;仓位||（mPosition ==位置和放大器;＆安培; mOffset＆LT;偏移））{
                     //滚动起来
                     //search_layout.setVisibility(View.GONE）;                }其他{
                     //向下滚动
                     //search_layout.setVisibility(View.VISIBLE）;                }
        }
    }）;
 

在当您滚动下跌隐藏布局，当你卷动起来，达到上面这个code 然后可见布局

I try to add a relativelayout when the user begin to scroll down in a listview. I would like to show the relativelayout again when the user scroll to top and when first item of the listview is displayed.

My code works but there is a little "climb" when the user try to scroll. I think that the problem is located on listAtTop function but i don't know where.

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);
    }

解决方案

Try this way

 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);

                }
        }
    }); 

In this code when you scroll down hide layout and when you scroll up and reached to top then Visible layout

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