读取SDcard Database并在Android ListView显示的处理流程

package sleek.listview; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.ListActivity; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; public class MyListViewActivity extends ListActivity { /** Called when the activity is first created. */ //定义SQLiteDatabase对象,用于处理数据库的操作 private SQLiteDatabase db = null; //定义Cursor游标,用于管理数据，比如获得数据库的每一行数据 private Cursor cursor = null; //定义一个列表储存 mData private List<Map<String, Object>> mData; //获取自定义的function function function = new function(); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //初始化数据库，创建文件夹和数据库文件 function.initDatabase(); mData = getData(); MyAdapter adapter = new MyAdapter(this); setListAdapter(adapter); } private List<Map<String, Object>> getData() { List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); //使用SQLiteDatabase的openOrCreateDatabase获取SDcard的数据库 //config.f 是在config.java里定义的文件路径变量 db = SQLiteDatabase.openOrCreateDatabase(config.f, null); Map<String, Object> map = new HashMap<String, Object>(); try { //查询test_listview数据 cursor = db.query("test_listview", new String[]{}, null, null, null, null, null); //通过强大的cursor把数据库的资料一行一行地读取出来 while(cursor.moveToNext()){ String text = cursor.getString(cursor.getColumnIndex("text")); map = new HashMap<String, Object>(); map.put("text", text); map.put("img", R.drawable.info); list.add(map); } } catch (Exception e) { // TODO: handle exception Log.i("LogDemo", e.toString()); } return list; } @Override protected void onListItemClick(ListView l, View v, int position, long id) { super.onListItemClick(l, v, position, id); function.showDialog((String)mData.get(position).get("text"), MyListViewActivity.this); //Toast.makeText(MyListViewActivity.this, (String)mData.get(position).get("text"), Toast.LENGTH_LONG).show(); } public final class ViewHolder{ public ImageView img; public TextView text; } public class MyAdapter extends BaseAdapter{ private LayoutInflater mInflater; ViewHolder holder = null; public MyAdapter(Context context){ this.mInflater = LayoutInflater.from(context); } @Override public int getCount() { // TODO Auto-generated method stub return mData.size(); } @Override public Object getItem(int arg0) { // TODO Auto-generated method stub return null; } @Override public long getItemId(int arg0) { // TODO Auto-generated method stub return 0; } @Override public View getView(int position, View convertView, ViewGroup parent) { if (convertView == null) { holder=new ViewHolder(); convertView = mInflater.inflate(R.layout.list, null); holder.img = (ImageView)convertView.findViewById(R.id.img); holder.text = (TextView)convertView.findViewById(R.id.text); convertView.setTag(holder); }else { holder = (ViewHolder)convertView.getTag(); } holder.img.setBackgroundResource((Integer)mData.get(position).get("img")); //把字符串设置在TextView上显示 holder.text.setText((String)mData.get(position).get("text")); return convertView; } } public void createDataBase() throws IOException{ File dbdir = config.path; if(!dbdir.exists()){ dbdir.mkdirs(); } if(!config.f.exists()){ config.f.createNewFile(); SQLiteDatabase.openOrCreateDatabase(config.f, null); copyDataBase(); } } private void copyDataBase() throws IOException { InputStream myInput; //复制到的目标路径 String outFileName = config.CR_URL_DBTABLE; OutputStream myOutput = new FileOutputStream(outFileName); //获取Assets文件夹中的databae.db myInput = this.getAssets().open(config.CR_DBNAME); byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer)) > 0) { myOutput.write(buffer, 0, length); } myOutput.flush(); myInput.close(); myOutput.close(); } }