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我創建了一個硬編碼的listView，現在我想改變它從SD卡上的dB填充。列表視圖和SQLite的SD幫助
我創建了一個包含底部光標的SQLHelper（從HERE借用），我修改了getExternalStorageState和getExternalStorageDirectory來設置我的dB路徑。
我讀了幾個關於這個主題的教程，但現在我迷了路，不知道如何修改我現有的類以使用SQLHelper來獲取listView來填充。任何幫助，建議，或片段將不勝感激，我希望這篇文章可以幫助任何人編碼他們自己n2角落 - 大聲笑 THNX！
SQLHelper.java我需要實現：
public class AC_SqlHelper extends SQLiteOpenHelper
{
static String extStorageDirectory;
public void sdState()
{
if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
{
extStorageDirectory = Environment.getExternalStorageDirectory().toString();
}
else
{
//TODO
}
}
public static final String DATABASE_PATH = (extStorageDirectory + "/Folder/Folder/dB/");
public static final String DATABASE_NAME = "myAppDB";
public static final String TABLE_NAME = "aTable";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_LABEL = "label";
public static final String COLUMN_TITLE = "title";
public static final String COLUMN_CAPTION = "caption";
public static final String COLUMN_URL = "url";
public SQLiteDatabase dbSqlite;
private final Context myContext;
public AC_SqlHelper(Context context)
{
super(context, DATABASE_NAME, null, 1);
this.myContext = context;
}
@Override
public void onCreate(SQLiteDatabase db)
{
// check if exists and copy database from resource
createDB();
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
Log.w("SqlHelper", "Upgrading database from version " + oldVersion
+ " to " + newVersion + ", which will destroy all old data");
onCreate(db);
}
public void createDatabase()
{
createDB();
}
private void createDB()
{
boolean dbExist = DBExists();
if (!dbExist)
{
copyDBFromResource();
}
}
private boolean DBExists()
{
SQLiteDatabase db = null;
try {
String databasePath = DATABASE_PATH + DATABASE_NAME;
db = SQLiteDatabase.openDatabase(databasePath, null,
SQLiteDatabase.OPEN_READWRITE);
db.setLocale(Locale.getDefault());
db.setLockingEnabled(true);
db.setVersion(1);
} catch (SQLiteException e)
{
Log.e("SqlHelper", "database not found");
}
if (db != null)
{
db.close();
}
return db != null ? true : false;
}
private void copyDBFromResource()
{
InputStream inputStream = null;
OutputStream outStream = null;
String dbFilePath = DATABASE_PATH + DATABASE_NAME;
try
{
inputStream = myContext.getAssets().open(DATABASE_NAME);
outStream = new FileOutputStream(dbFilePath);
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) > 0)
{
outStream.write(buffer, 0, length);
}
outStream.flush();
outStream.close();
inputStream.close();
}
catch (IOException e)
{
throw new Error("Problem copying database from resource file.");
}
}
public void openDataBase() throws SQLException
{
String myPath = DATABASE_PATH + DATABASE_NAME;
dbSqlite = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close()
{
if (dbSqlite != null)
dbSqlite.close();
super.close();
}
public Cursor getCursor()
{
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
queryBuilder.setTables(TABLE_NAME);
String[] asColumnsToReturn = new String[] { COLUMN_ID, COLUMN_LABEL,
COLUMN_TITLE, COLUMN_CAPTION, COLUMN_URL };
Cursor mCursor = queryBuilder.query(dbSqlite, asColumnsToReturn, null,
null, null, null, "title ASC");
return mCursor;
}
}
這是我目前列表活動（AC_List.java）：
public class List_AC extends Activity
{
protected TextView activityTitle;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.list_view);
activityTitle = (TextView) findViewById(R.id.titleBarTitle);
activityTitle.setText("ADVISORY CIRCULATORS");
ArrayList<SearchResult> searchResults = GetSearchResults();
final ListView lv1 = (ListView) findViewById(R.id.listItems);
lv1.setAdapter(new MyCustomBaseAdapter(this, searchResults));
lv1.setOnItemClickListener(new OnItemClickListener()
{
public void onItemClick(AdapterView<?> a, View v, int position, long id)
{
Object o = lv1.getItemAtPosition(position);
SearchResult fullObject = (SearchResult)o;
Toast.makeText(List_AC.this, "You have chosen: " + " " + fullObject.getListTitle(), Toast.LENGTH_LONG).show();
Intent i = new Intent(List_AC.this, View_ACdoc.class);
i.putExtra("url", fullObject.getURL());
startActivity(i);
}
});
private ArrayList<SearchResult> GetSearchResults()
{
ArrayList<SearchResult> results = new ArrayList<SearchResult>();
SearchResult sr1 = new SearchResult();
sr1.setLabel("A Label");
sr1.setListTitle("The Title");
sr1.setCaption("Some captions.");
sr1.setURL("http://www.mysite/index.html");
results.add(sr1);
return results;
}
}
...並在下文中我目前的支持類：
MyCustomBaseAdapter.java：
public class MyCustomBaseAdapter extends BaseAdapter {
private static ArrayList<SearchResult> searchArrayList;
private LayoutInflater mInflater;
public MyCustomBaseAdapter(Context context, ArrayList<SearchResult> results) {
searchArrayList = results;
mInflater = LayoutInflater.from(context);
}
public int getCount() {
return searchArrayList.size();
}
public Object getItem(int position) {
return searchArrayList.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
holder.txtLabel = (TextView) convertView.findViewById(R.id.label);
holder.txtListTitle = (TextView) convertView.findViewById(R.id.listTitle);
holder.txtCaption = (TextView) convertView.findViewById(R.id.caption);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.txtLabel.setText(searchArrayList.get(position).getLabel());
holder.txtListTitle.setText(searchArrayList.get(position).getListTitle());
holder.txtCaption.setText(searchArrayList.get(position).getCaption());
return convertView;
}
static class ViewHolder {
TextView txtLabel;
TextView txtListTitle;
TextView txtCaption;
}
}
SearchResult.java：
public class SearchResult
{
private String label = "";
private String listTitle = "";
private String caption = "";
private String listURL = "";
private String listActivity = "";
public void setLabel(String label) {
this.label = label;
}
public String getLabel() {
return label;
}
public void setListTitle(String listTitle) {
this.listTitle = listTitle;
}
public String getListTitle() {
return listTitle;
}
public void setCaption(String caption) {
this.caption = caption;
}
public String getCaption() {
return caption;
}
//
public void setURL(String listURL) {
this.listURL = listURL;
}
public String getURL() {
return listURL;
}
public void setActivity(String listActivity) {
this.listActivity = listActivity;
}
public String getActivity() {
return listActivity;
}
}