Question

我只是使用Baseadapter在listview上创建，但我突然得到错误 “java.lang.ClassCastException：java.lang.Integer无法强制转换为com.play.findnearplace.Md $ Holder”问题出在getView（）中，否则条件持有者得到整数vlue就像0。

public class Md extends BaseAdapter implements Filterable {
    public List<FD> itemsData;
    public List<FD> orig;
    OnClickListener onclick;
    Context context;
    int id;

    public Md(List<FD> itemsData, OnClickListener onclick, int id,MainActivity main) {
        this.itemsData = itemsData;
        this.onclick = onclick;
        this.id = id;
        this.context=main;

    }

    @Override
    public int getCount() {
        return itemsData.size();
    }

    @Override

    public Object getItem(int position) {
        return position;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }
    private class Holder
    {
        public ImageView ui;
        public TextView tt;

        public RelativeLayout rl_main_child;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        Holder holder;  
        Log.i("Second", "1");
        LayoutInflater mInflater = (LayoutInflater) 
                context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if(convertView==null)
        {

            Log.i("Second", "2");
        convertView=mInflater.inflate(R.layout.main_child, parent,false);
        holder = new Holder();
        Log.i("Second", "3");
        holder.ui = (ImageView) convertView.findViewById(R.id.imgunit);
        holder.tt = (TextView) convertView.findViewById(R.id.txttitle);

        convertView.setTag(holder);
        Log.i("Second", ""+holder);
        }else
        {
            Log.i("Second", ""+convertView.getTag());
            holder=(Holder) convertView.getTag();
        }
        Log.i("Second", "5");
        FD m=itemsData.get(position);
        holder.rl_main_child=(RelativeLayout) convertView.findViewById(R.id.rl_main_child);
        holder.rl_main_child.setTag(position);
         holder.tt.setText(m.gettitle());
        holder.rl_main_child.setOnClickListener(onclick);
        return convertView;
    }

    @Override
    public Filter getFilter() {
        // TODO Auto-generated method stub
        return new Filter() {

            @Override
            protected FilterResults performFiltering(CharSequence constraint) {
                final FilterResults oReturn = new FilterResults();
                final List<FD> results = new ArrayList<FD>();
                if (orig == null)
                    orig = itemsData;
                if (constraint != null) {
                    if (orig != null && orig.size() > 0) {
                        for (final FD g : orig) {
                            if (g.gettitle().toLowerCase()
                                    .contains(constraint.toString()))
                                results.add(g);
                        }
                    }
                    oReturn.values = results;
                }
                return oReturn;
            }

            @SuppressWarnings("unchecked")
            @Override
            protected void publishResults(CharSequence constraint,
                    FilterResults results) {
                // TODO Auto-generated method stub
                 itemsData = (ArrayList<FD>) results.values;
                notifyDataSetChanged();
            }
        };
    }
    public void notifyDataSetChanged() {
        super.notifyDataSetChanged();
    }

}

错误.....

05-18 23:43:20.434: E/AndroidRuntime(14417): FATAL EXCEPTION: main
05-18 23:43:20.434: E/AndroidRuntime(14417): Process: com.play.findnearplace, PID: 14417
05-18 23:43:20.434: E/AndroidRuntime(14417): java.lang.ClassCastException: java.lang.Integer cannot be cast to com.play.findnearplace.Md$Holder
05-18 23:43:20.434: E/AndroidRuntime(14417):    at com.play.findnearplace.Md.getView(Md.java:80)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.widget.AbsListView.obtainView(AbsListView.java:2303)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.widget.ListView.measureHeightOfChildren(ListView.java:1273)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.widget.ListView.onMeasure(ListView.java:1182)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.view.View.measure(View.java:16834)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5374)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1621)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:742)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:607)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.view.View.measure(View.java:16834)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5374)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:340)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.view.View.measure(View.java:16834)
05-18 23:43:20.434: E/AndroidRuntime(14417):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5374)
05-18 23:43:20.434: E/AndroidRuntime(14417):

我的日志.....

05-19 00:28:14.646: I/Second(17516): 1
05-19 00:28:14.646: I/Second(17516): 2
05-19 00:28:14.655: I/Second(17516): 3
05-19 00:28:14.655: I/Second(17516): com.play.findnearplace.Md$Holder@42544570
05-19 00:28:14.655: I/Second(17516): 5
05-19 00:28:14.660: I/Second(17516): 1
05-19 00:28:14.660: I/Second(17516): 0

main_child

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/rl_main_child"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" >

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="5dp"
        android:paddingTop="5dp" >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="55dp"
            android:layout_marginLeft="35dp"
            android:background="@color/white" >

            <com.play.findnearplace.T
                android:id="@+id/txttitle"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="35dp"
                android:layout_marginTop="3dp"
                android:textColor="@color/secondary"
                android:textSize="15sp"
                android:visibility="visible" />
        </LinearLayout>

        <ImageView
            android:id="@+id/imgunit"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:background="@drawable/rounded_corner"
            android:src="@drawable/ic_launcher" />
    </FrameLayout>

</RelativeLayout>

Answer 1

问题在于这两行：

  holder.rl_main_child=(RelativeLayout) convertView.findViewById(R.id.rl_main_child);
  holder.rl_main_child.setTag(position);

在第一个中，您将convertView分配给rl_main_child，第二个是您覆盖标记。因此，第二次调用getView时，您会尝试将标记转换为Holder，但由于您使用整数position覆盖它，因此会得到ClassCastException。摆脱holder.rl_main_child.setTag(position);，它将起作用

Answer 2

行FD m=itemsData.get(position);导致问题。您正在尝试将int转换为FD类型

Answer 3

试试这个：

if(convertView==null) {
    // your existing code
    holder.rl_main_child=(RelativeLayout) convertView.findViewById(R.id.rl_main_child);
    convertView.setTag(holder);
}
else {
   // your existing code
}

// no need to do below statement, hence commented
//holder.rl_main_child.setTag(position);
holder.tt.setText(m.gettitle());
holder.rl_main_child.setOnClickListener(onclick);

java.lang.ClassCastException：java.lang.Integer无法强制转换为com.play.findnearplace.Md $ Holder

3 个答案: