【发布时间】：2015-12-05 04:48:07
【问题描述】：
我正在使用的列表视图有问题。列表视图中的每个项目都有两个按钮，用户可以使用它们来添加或减少每位参赛者的分数。
问题是当我向列表视图中添加新项目或滚动时（在添加了至少一个项目后），代码会随机从一个或多个项目的按钮中取出文本。
谁能告诉我 A) 是什么原因造成的？ B) 如何解决？
我已经包含了我认为相关的代码。如果您认为我需要在此处添加更多内容，请告诉我。
我的适配器类：
public class ContestantListAdapter extends BaseAdapter {
private ArrayList<ContestantItem> contestantList;
private LayoutInflater layoutInflater;
public ContestantListAdapter(Context context, ArrayList<ContestantItem> contestantList){
this.contestantList = contestantList;
layoutInflater = LayoutInflater.from(context);
}
@Override
public int getCount(){
return contestantList.size();
}
public View getView(int position, View convertView, ViewGroup parentView){
ViewHolder viewHolder;
if(convertView == null){
convertView = layoutInflater.inflate(R.layout.contestant_row_layout,null);//null might need to be activity_main
viewHolder = new ViewHolder();
viewHolder.nameView = (TextView) convertView.findViewById(R.id.nameView);
viewHolder.pointsView = (TextView) convertView.findViewById(R.id.pointsView);
convertView.setTag(viewHolder);
}else{
viewHolder = (ViewHolder)convertView.getTag();
}
viewHolder.nameView.setText((contestantList.get(position).getName()));
viewHolder.pointsView.setText(Integer.toString(contestantList.get(position).getPoints()));
//get button position
Button button =(Button) convertView.findViewById(R.id.Minus);
button.setOnClickListener(minusListener);
Button buttonPlus = (Button) convertView.findViewById(R.id.Plus);
buttonPlus.setOnClickListener(addListener);
return convertView;
}
private View.OnClickListener minusListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
View parentRow = (View) v.getParent();
ListView listView = (ListView) parentRow.getParent();
final int position = listView.getPositionForView(parentRow);
ContestantItem tmpContestant = (ContestantItem) contestantList.get(position);
int tmpPoints = tmpContestant.getPoints()-1;
if(tmpPoints<0){tmpPoints=0;}
tmpContestant.setPoints(tmpPoints);
notifyDataSetChanged();
}
};
private View.OnClickListener addListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
View parentRow = (View) v.getParent();
ListView listView = (ListView) parentRow.getParent();
final int position = listView.getPositionForView(parentRow);
ContestantItem tmpContestant = (ContestantItem) contestantList.get(position);
int tmpPoints = tmpContestant.getPoints()+1;
tmpContestant.setPoints(tmpPoints);
notifyDataSetChanged();
}
};
static class ViewHolder {
TextView nameView;
TextView pointsView;
}
@Override
public Object getItem(int index){
return contestantList.get(index);
}
@Override
public long getItemId(int index){
return index;
}
//this method should add the contestent to the listView. must know what position to add it in.
public void addItem(String name, int index){
ContestantItem tempContestant = new ContestantItem();
tempContestant.setName(name);
tempContestant.setPoints(1);
contestantList.add(index,tempContestant);
notifyDataSetChanged();
}
. . .
参赛者行布局：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_weight="0.15"
android:id="@+id/Minus"
android:text="@string/minus"
/>
<TextView
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_weight="0.5"
android:id="@+id/nameView"
/>
<TextView
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_weight="0.2"
android:id="@+id/pointsView"
/>
<Button
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_weight="0.15"
android:id="@+id/Plus"
android:text="@string/plus"
/>
</LinearLayout>
主要活动：
public class MainActivity extends AppCompatActivity implements ContestantsFragment.OnFragmentInteractionListener{
ListView listView1;
ContestantListAdapter contestantAdapter;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayList<ContestantItem> rowDetails = getListData();
listView1 = (ListView) findViewById(R.id.contactsListView);
listView1.setAdapter(new ContestantListAdapter(this,rowDetails));
contestantAdapter = (ContestantListAdapter) listView1.getAdapter();
}
private ArrayList getListData(){
ArrayList<ContestantItem> contestantList = new ArrayList<ContestantItem>();
ContestantItem cItem;
for(int i=0;i<10;i++){
cItem = new ContestantItem();
cItem.setName("Danny Anderson");
cItem.setPoints(5);
contestantList.add(cItem);
}
return contestantList;
}
@Override
public void onFragmentInteraction(Uri uri) {
}
//if the name is found returns the index position in the list. If not found -99
public void findAlphabetical(View view){
//TODO implement Binary search algorithm.
hideKeyboard();
EditText tmpEditTxt = (EditText) findViewById(R.id.searchField);
String inputTxt = tmpEditTxt.getText().toString();
int findAtIndex =contestantAdapter.searchAlphabetical(inputTxt)-1;
if(findAtIndex <0){findAtIndex=0;}
listView1.smoothScrollToPosition(findAtIndex);
}
public void addInAlpabetOrder(View view){
//TODO add the name in alphabetical order
hideKeyboard();
//ListView tmpListView = (ListView) contestantsFragment.getView().findViewById(R.id.contactsListView);
EditText tmpEditTxt = (EditText) findViewById(R.id.searchField);
String inputTxt = tmpEditTxt.getText().toString();
int addAtIndex =contestantAdapter.searchAlphabetical(inputTxt);
contestantAdapter.addItem(inputTxt, addAtIndex);
listView1.smoothScrollToPosition(addAtIndex);
}
public void clearContestantList(View view){
//TODO clear out all contestants from the list
contestantAdapter.clearAllItems();
}
. . .
【问题讨论】：
-
在视图保持器内添加按钮，与 TextView 相同。
-
@SuhasBachewar，你是对的，与特定文本视图无关，因为视图持有者无法判断单击了哪个按钮。他必须在 ViewHolder 中同时拥有加号和减号按钮
-
谢谢大家，我将按钮添加到 ViewHolder 中，它仍然随机使按钮变为空白。我什至在 getView 方法中设置按钮文本，我遇到了同样的问题。我使用的是相当便宜的手机，这可能是由于主线程上发生的事情过多造成的吗？
-
那么你解决了吗？如果是的话，你能告诉我路吗？
-
具体的实现细节我太久记不住了。这个问题是由于我没有使用好的架构造成的。我制作了一个普通的旧 java 对象来保存列表中每个项目的状态，然后更新了 onBindViewHolder 中的 viewHolder
标签： android listview scroll listviewitem