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Android ListView与ScrollView冲突的解决方法总结

作者:lqh  发布时间:2022-09-05 21:44:03 

标签:Android,ListView,ScrollView

Android ListView与ScrollView冲突的解决方法总结

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));
}
}

感谢阅读,希望能帮助到大家,谢谢大家对本站的支持!

来源:http://blog.csdn.net/mp624183768/article/details/55004683

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