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Android ListView与ScrollView冲突的解决方法总结

程序员文章站 2023-01-05 21:26:43
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scro...

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)); 
 } 
} 

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