众所周知ListView与ScrollView都具有滚动能力,对于这样的View控件,当ScrollView与ListView相互嵌套会成为一种问题:
问题一:ScrollView与ListView嵌套导致ListView显示不全面
问题二:ScrollView不能正常滑动
解决方式一:
ScrollView+LinearLayout+ListView可以换成ScrollView+LinearLayout+LinearLayout,对于开发中,ScrollView所能滚动的样式形式各异,另外的话,ScrollView所显示的内容肯定不会太多,因此这种方案是合理而且可选的
解决方式二:
同样是替换:ListView具有HeaderView与FooterView2部分,因此,在非下拉刷新,上拉加载的需求中,完全可以使用ListView来代替ScrollView,因此是合理可选的方案
解决方式三:
主动计算和设置ListView的高度,这样的结果最终得出类似解决方案一效果,具体来说缺点是大材小用,但也是合理的解决办法。
public class Utility { public static void setListViewHeightBasedOnChildren(ListView listView) { ListAdapter listAdapter = listView.getAdapter(); if (listAdapter == null) { return; } int totalHeight = 0; for (int i = 0; i < listAdapter.getCount(); i++) { View listItem = listAdapter.getView(i, null, listView); listItem.measure(0, 0); totalHeight += listItem.getMeasuredHeight(); } ViewGroup.LayoutParams params = listView.getLayoutParams(); params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1)); listView.setLayoutParams(params); } }
解决方式四:
复写ScrollView,从事件方向进行处理,缺点是灵活性不够好
public class ListScrollView extends ScrollView { private List list = new ArrayList(); private int scrollPaddingTop; // scrollview的顶部内边距 private int scrollPaddingLeft;// scrollview的左侧内边距 private int[] scrollLoaction = new int[2]; // scrollview在窗口中的位置 private final static int UPGLIDE = 0; private final static int DOWNGLIDE = 1; private int glideState; public ListScrollView(Context context, AttributeSet attrs) { super(context, attrs); } private int downY = 0; private int moveY = 0; @Override public boolean dispatchTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: downY = (int) ev.getY(); //System.out.println("actiondown" + ev.getY()); break; case MotionEvent.ACTION_MOVE: moveY= (int) ev.getY(); //System.out.println("move" + moveY + "down" + downY); if((moveY - downY) >= 0) { //System.out.println("‘‘‘‘‘‘‘‘‘DOWNGLIDE‘‘‘‘‘‘‘‘‘‘‘"); glideState = DOWNGLIDE; } else { //System.out.println("‘‘‘‘‘‘‘‘‘UPGLIDE‘‘‘‘‘‘‘‘‘‘‘"); glideState = UPGLIDE; } break; case MotionEvent.ACTION_UP: default: break; } return super.dispatchTouchEvent(ev); } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { // 该事件的xy是以scrollview的左上角为00点而不是以窗口为00点 int x = (int) ev.getX() + scrollLoaction[0]; int y = (int) ev.getY() + scrollLoaction[1]; for (int i = 0; i < list.size(); i++) { ListView listView = list.get(i); int[] location = new int[2]; listView.getLocationInWindow(location); int width = listView.getWidth(); int height = listView.getHeight(); // 在listview的位置之内则可以滑动 if (x >= location[0] + scrollPaddingLeft && x <= location[0] + scrollPaddingLeft + width && y >= location[1] + scrollPaddingTop && y <= location[1] + scrollPaddingTop + height) { //System.out.println(glideState); if(( (listView.getLastVisiblePosition() == (listView.getCount()-1)) && (glideState == UPGLIDE) ) ) { //System.out.println("up"); break; } if(( (listView.getFirstVisiblePosition() == 0) && (glideState == DOWNGLIDE))) { //System.out.println("down"); break; } return false; //让子控件直接处理 } } return super.onInterceptTouchEvent(ev); } @Override public boolean onTouchEvent(MotionEvent ev) { return super.onTouchEvent(ev); } private void findAllListView(View view) { if (view instanceof ViewGroup) { int count = ((ViewGroup) view).getChildCount(); for (int i = 0; i < count; i++) { if (!(view instanceof ListView)) { findAllListView(((ViewGroup) view).getChildAt(i)); } } if (view instanceof ListView) { list.add((ListView) view); } } } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); scrollPaddingTop = getTop(); scrollPaddingLeft = getLeft(); getLocationInWindow(scrollLoaction); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); if (this.getChildCount() != 1) { try { throw new ScrollException(); } catch (ScrollException e) { e.printStackTrace(); } } list.clear(); findAllListView(this.getChildAt(0)); } }
时间: 2024-12-29 16:11:47