我正在尝试将数据保存在 sqlite 数据库上。我的问题是我不知道为什么 ListView 的适配器没有显示。我有一个对话框来获取值，然后单击接受，我将值发送到数据库，然后我试图在 ListView 上显示结果。
我做错了什么？
代码：
服务器SQLiteDB
public class ServersSQLiteDB extends SQLiteOpenHelper {
// Sentencia SQL para crear la tabla de Usuarios
String sqlCreate = "CREATE TABLE ServerDB (code INTEGER PRIMARY KEY AUTOINCREMENT, address TEXT, mntFolder TEXT, resorceName TEXT)";
public ServersSQLiteDB(Context context, String dbname,
CursorFactory factory, int version) {
super(context, dbname, factory, version);
}
@Override
public void onCreate(SQLiteDatabase db) {
// Se ejecuta la sentencia SQL de creación de la tabla
db.execSQL(sqlCreate);
}
@Override
public void onUpgrade(SQLiteDatabase db, int previousVersion, int newVersion) {
// Se elimina la versión anterior de la tabla
db.execSQL("DROP TABLE IF EXISTS ServerDB");
// Se crea la nueva versión de la tabla
db.execSQL(sqlCreate);
}
}
服务器
public class Server {
private int code = -1;
private String address = "";
private String mntFolder = "";
private String resourceName = "";
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getMntFolder() {
return mntFolder;
}
public void setMntFolder(String mntFolder) {
this.mntFolder = mntFolder;
}
public String getResourceName() {
return resourceName;
}
public void setResourceName(String resourceName) {
this.resourceName = resourceName;
}
}
自定义基础适配器
public class CustomBaseAdapter extends BaseAdapter {
private static ArrayList<Server> serverArrayList;
private LayoutInflater mInflater;
public CustomBaseAdapter(Context context, ArrayList<Server> results) {
serverArrayList = results;
mInflater = LayoutInflater.from(context);
}
public int getCount() {
return serverArrayList.size();
}
public Object getItem(int position) {
return serverArrayList.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.custom_row_view, null);
holder = new ViewHolder();
holder.txtAddress = (TextView) convertView.findViewById(R.id.address);
holder.txtMntFolder = (TextView) convertView
.findViewById(R.id.mntFolder);
holder.txtResourceName = (TextView) convertView.findViewById(R.id.resourceName);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.txtAddress.setText(serverArrayList.get(position).getAddress());
holder.txtMntFolder.setText(serverArrayList.get(position)
.getMntFolder());
holder.txtResourceName.setText(serverArrayList.get(position).getResourceName());
return convertView;
}
static class ViewHolder {
TextView txtAddress;
TextView txtMntFolder;
TextView txtResourceName;
}
}
最后，ServersActivity
public class ServersActivity extends Activity {
final Context context = this;
private Button btnAddServer;
private Button btnDelServer;
private EditText ed_address;
private EditText ed_mntFolder;
private EditText ed_resourceName;
private ListView lvServers;
private CustomBaseAdapter cAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_servers);
btnAddServer = (Button) findViewById(R.id.btnAdd);
btnDelServer = (Button) findViewById(R.id.btnDelete);
ArrayList<Server> serverResults = GetServerResults();
lvServers = (ListView) findViewById(R.id.lvServers);
cAdapter = new CustomBaseAdapter(this, serverResults);
lvServers.setAdapter(cAdapter);
lvServers.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> a, View v, int position,
long id) {
Object o = lvServers.getItemAtPosition(position);
Server fullObject = (Server) o;
Crouton.makeText(
ServersActivity.this,
"You have chosen: " + " "
+ fullObject.getResourceName(), Style.CONFIRM)
.show();
}
});
btnAddServer.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// get custom_dialog_layout.xml view
LayoutInflater li = LayoutInflater.from(context);
View customDialogView = li.inflate(
R.layout.custom_dialog_layout, null);
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
ServersActivity.this);
// set custom_dialog_layout.xml to alertdialog builder
alertDialogBuilder.setView(customDialogView);
ed_address = (EditText) customDialogView
.findViewById(R.id.etAddress);
ed_mntFolder = (EditText) customDialogView
.findViewById(R.id.etMntFolder);
ed_resourceName = (EditText) customDialogView
.findViewById(R.id.etResourceName);
// set the title of the Alert Dialog
alertDialogBuilder.setTitle(getResources().getString(
R.string.addDialogTitle));
// set dialog message
alertDialogBuilder
.setCancelable(false)
.setPositiveButton(
getResources().getString(R.string.accept),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int id) {
// Time to write data on SQLITE
if (isEmpty(ed_address)
&& isEmpty(ed_mntFolder)
&& isEmpty(ed_resourceName)) {
Crouton.makeText(
ServersActivity.this,
getString(R.string.emptyfields),
Style.INFO).show();
} else {
ServersSQLiteDB dbinstance = new ServersSQLiteDB(
ServersActivity.this,
"ServerDB", null, 1);
SQLiteDatabase db = dbinstance
.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("address", ed_address
.getText().toString());
values.put("mntFolder",
ed_mntFolder.getText()
.toString());
values.put("resorceName",
ed_resourceName.getText()
.toString());
db.insert("ServerDB", null, values);
db.close();
Log.i("INSERT", values.toString());
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager()
.getDefaultDisplay()
.getMetrics(metrics);
// metrics.heightPixels;
// metrics.widthPixels;
Crouton.makeText(
ServersActivity.this,
getString(R.string.insertion_ok),
Style.CONFIRM).show();
// Now we need to update the
// ListView
runOnUiThread(new Runnable() {
public void run() {
ArrayList<Server> serverResults = GetServerResults();
cAdapter = null;
cAdapter = new CustomBaseAdapter(ServersActivity.this, serverResults);
cAdapter.notifyDataSetChanged();
lvServers.setAdapter(cAdapter);
}
});
}
}
})
.setNegativeButton(
getResources().getString(R.string.cancel),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int id) {
dialog.cancel();
}
});
AlertDialog alertDialog = alertDialogBuilder.create();
alertDialog.show();
}
});
btnDelServer.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Time to delete the selected item of the listview
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.servers, menu);
return true;
}
private ArrayList<Server> GetServerResults() {
ArrayList<Server> results = new ArrayList<Server>();
ServersSQLiteDB dbinstance = new ServersSQLiteDB(ServersActivity.this,
"ServerDB", null, 1);
SQLiteDatabase db = dbinstance.getReadableDatabase();
Cursor c = db.rawQuery("SELECT * FROM ServerDB WHERE 0", null);
try {
// Nos aseguramos de que existe al menos un registro
if (c.moveToFirst()) {
// Recorremos el cursor hasta que no haya más registros
do {
int code = c.getInt(0);
String address = c.getString(1);
String mntFolder = c.getString(2);
String resourceName = c.getString(3);
Server dummy = new Server();
dummy.setCode(code);
dummy.setAddress(address);
dummy.setMntFolder(mntFolder);
dummy.setResourceName(resourceName);
Log.i("GET", dummy.toString());
results.add(dummy);
dummy = null;
} while (c.moveToNext());
}
} finally {
c.close();
db.close();
}
return results;
}
// Check if a EditText is empty
private boolean isEmpty(EditText etText) {
if (etText.getText().toString().trim().length() > 0) {
return false;
} else {
return true;
}
}
}
感谢您的所有评论。