【发布时间】：2016-09-21 01:59:10
【问题描述】：
我有一个带有如下物品装饰的 recyclerView：
public class VerticalItemDecoration extends RecyclerView.ItemDecoration{
private int space;
public VerticalItemDecoration(int space){
this.space = space;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state){
outRect.top = space;
Log.e("Decor", "Parent: " + parent + " Childs: " + parent.getChildCount());
if (parent.getChildLayoutPosition(view) == 0){
outRect.top = 0;
}
}
}
每 10 秒，我将遍历此回收器视图中的数据并调用 iterator.remove()。在那之后，我通知适配器该项目已被删除。但是，在删除该项目后，getItemOffsets() 会为该回收站视图调用两次。第一次显示 1 个子视图，这是正确的，因为我删除了一个。但在那之后，它再次被调用并报告 2 个子视图。这仅在移除项目时发生。这是什么原因造成的？
我是这样迭代的：
for (Iterator<Client> iterator = AdapterClients.listClients.iterator(); iterator.hasNext();){
Client client1 = iterator.next();
if (client.getMacAddress().equals(client1.getMacAddress())){
//This client is already on the adapter
clientExists = true;
//Make sure the client is still reachable
if (ApManager.isClientReachable(client1, 3000)){
//Client is still reachable
//Update the client's information
if (client1.getHostName().equals("Unknown Host Name")){
client1.setHostName(ApManager.getHostName(client1));
notifyAdapter("itemChanged", AdapterClients.listClients.indexOf(client1));
}
}else{
//Client is no longer reachable, remove it from the adapter
int index = AdapterClients.listClients.indexOf(client1);
iterator.remove();
Log.e("Arp", "index: " + index + " objIndex: " + AdapterClients.listClients.indexOf(client1));
notifyAdapter("itemRemoved", index);
DataLogger.log("Client " + client1.getIpAddress() + " disconnected from \"" + ApManager.getActiveHotspot().getSsid() + "\"");
}
}
}
notifyAdapter() 方法如下所示：
private static void notifyAdapter(final String action, final int index){
new Handler(Looper.getMainLooper()).post(new Runnable(){
@Override
public void run(){
switch (action){
case "itemInserted":
Log.e("Arp", "itemInserted");
FragmentClients.adapterClients.notifyItemInserted(index);
break;
case "itemRemoved":
Log.e("Arp", "itemRemoved");
FragmentClients.adapterClients.notifyItemRemoved(index);
Log.e("Arp", "after itemRemoved");
break;
//Other cases...
}
FragmentClients.updateText();
//FragmentClients.adapterClients.notifyItemChanged(0);
FragmentHotspots.adapterHotspots.notifyItemChanged(AdapterHotspots.listHotspots.indexOf(ApManager.getActiveHotspot()));
}
});
}
这是 logcat 的输出：
05-23 18:58:57.143 4726-5658/com.example E/Arp: index: 0 objIndex: -1
05-23 18:58:57.154 4726-4726/com.example E/Arp: itemRemoved
05-23 18:58:57.154 4726-4726/com.example E/Arp: after itemRemoved
05-23 18:58:57.171 4726-4726/com.example E/Decor: Parent: android.support.v7.widget.RecyclerView{b0a533b VFED.... .F....I. 0,0-1080,1509 #7f0e009b app:id/recyclerViewClients} Childs: 1
05-23 18:58:57.174 4726-4726/com.example E/Decor: Parent: android.support.v7.widget.RecyclerView{b0a533b VFED.... .F....I. 0,0-1080,1509 #7f0e009b app:id/recyclerViewClients} Childs: 2
05-23 18:58:57.187 4726-4726/com.example E/Decor: Parent: android.support.v7.widget.RecyclerView{3d927634 VFED.... ......I. 0,0-1080,1509 #7f0e009d app:id/recyclerViewHotspots} Childs: 1
注意：使用notifyDataSetChanged() 代替notifyItemRemoved() 有效，但动画不显示。
【问题讨论】：
标签： java android iterator android-recyclerview