自定义ListView适配器中的自定义字体（unicode）不显示

Question

我想用Unicode创建自定义列表适配器。这是我的代码，它编译没有任何错误，但它的Unicode字符没有显示。请帮我纠正这个问题。谢谢你。

CustomListViewAdapter

package com.theopentutorials.android.beans;

import java.util.List;

import com.theopentutorials.android.R;
import com.theopentutorials.android.beans.RowItem;

import android.app.Activity;
import android.content.Context;
import android.graphics.Typeface;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class CustomListViewAdapter extends ArrayAdapter<RowItem> {

    Context context;

    public CustomListViewAdapter(Context context, int resourceId,
            List<RowItem> items) {
        super(context, resourceId, items);
        this.context = context;
    }

    /* private view holder class */
    private class ViewHolder {
        ImageView imageView;
        TextView txtTitle;
        TextView txtDesc;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        RowItem rowItem = getItem(position);

        LayoutInflater mInflater = (LayoutInflater) context
                .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.list_item, null);
            holder = new ViewHolder();
            holder.txtDesc = (TextView) convertView.findViewById(R.id.desc);
            holder.txtTitle = (TextView) convertView.findViewById(R.id.title);
            holder.imageView = (ImageView) convertView.findViewById(R.id.icon);
            convertView.setTag(holder);
        } else
            holder = (ViewHolder) convertView.getTag();

        holder.txtDesc.setText(rowItem.getDesc());
        holder.txtTitle.setText(rowItem.getTitle());
        holder.imageView.setImageResource(rowItem.getImageId());

        return convertView;
    }
}

ImageTextListViewActivity

    package com.theopentutorials.android.beans;

import java.util.ArrayList;
import java.util.List;

import com.theopentutorials.android.R;

import android.app.Activity;
import android.graphics.Typeface;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;

public class ImageTextListViewActivity extends Activity implements
        OnItemClickListener {

    public static final String[] titles = new String[] { "කළමනාකාරීත්වයක්",
            "පරිසරයට", "සමාගම ", "XXXXXX " };

    public static final String[] descriptions = new String[] {
            "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
            "cccccccccccccccccccccccccccccc", "dddddddddddddddddddddddddddddd" };

    public static final Integer[] images = { R.drawable.straw,
            R.drawable.banana, R.drawable.orange, R.drawable.mixed };

    ListView listView;
    List<RowItem> rowItems;
    public Typeface myTypeface;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        myTypeface = Typeface
                .createFromAsset(getAssets(), "fonts/iskpotab.ttf");

        EditText edt1 = (EditText) findViewById(R.id.editText1);
        edt1.setText("කළමනාකාරීත්වයක්");

        edt1.setTypeface(myTypeface);

        rowItems = new ArrayList<RowItem>();
        for (int i = 0; i < titles.length; i++) {
            RowItem item = new RowItem(images[i], titles[i], descriptions[i]);
            rowItems.add(item);
        }

        listView = (ListView) findViewById(R.id.list);

        CustomListViewAdapter adapter = new CustomListViewAdapter(this,
                R.layout.list_item, rowItems);

        listView.setAdapter(adapter);

        listView.setOnItemClickListener(this);
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        Toast toast = Toast.makeText(getApplicationContext(), "Item "
                + (position + 1) + ": " + rowItems.get(position),
                Toast.LENGTH_SHORT);
        toast.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0, 0);
        toast.show();
    }
}

RowItem

    package com.theopentutorials.android.beans;
public class RowItem {
    private int imageId;
    private String title;
    private String desc;

    public RowItem(int imageId, String title, String desc) {
        this.imageId = imageId;
        this.title = title;
        this.desc = desc;
    }
    public int getImageId() {
        return imageId;
    }
    public void setImageId(int imageId) {
        this.imageId = imageId;
    }
    public String getDesc() {
        return desc;
    }
    public void setDesc(String desc) {
        this.desc = desc;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    @Override
    public String toString() {
        return title + "\n" + desc;
    }   
}
    package com.theopentutorials.android.beans;

import java.util.HashMap;
import java.util.List;

import com.theopentutorials.android.R;

import android.content.Context;
import android.graphics.Typeface;
import android.view.View;
import android.view.ViewGroup;
import android.widget.SimpleAdapter;
import android.widget.TextView;

public class SpecialAdapter extends SimpleAdapter {
    public SpecialAdapter(Context context, List<HashMap<String, String>> items,
            int resource, String[] from, int[] to) {
        super(context, items, resource, from, to);
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        View view = super.getView(position, convertView, parent);

        ((TextView) view.findViewById(R.id.desc)).setTypeface(Typeface
                .createFromAsset(view.getContext().getAssets(),
                        "fonts/iskpotab.ttf"));

        ((TextView) view.findViewById(R.id.title)).setTypeface(Typeface
                .createFromAsset(view.getContext().getAssets(),
                        "fonts/iskpotab.ttf"));

        return view;
    }
}