我在我的android studio項目中發現錯誤。我嘗試添加SQLite到我的片段。這是錯誤。參數UserFragment無法轉換爲片段
Error:(75, 25) error: method updateDisplay in class MainMenu cannot be applied to given types; required: Fragment found: UserFragment reason: actual argument UserFragment cannot be converted to Fragment by method invocation conversion
MainMenu.Java
public class MainMenu extends ActionBarActivity {
private DrawerLayout mDrawerLayout;
private NavigationView navigationView;
String address = null;
private ProgressDialog progress;
BluetoothAdapter myBluetooth = null;
BluetoothSocket btSocket = null;
private boolean isBtConnected = false;
//SPP UUID. Look for it
static final UUID myUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_menu);
Intent newint = getIntent();
address = newint.getStringExtra(DeviceList.EXTRA_ADDRESS);
new ConnectBT().execute();
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
ActionBar actionBar = getSupportActionBar();
actionBar.setHomeAsUpIndicator(R.drawable.ic_menu);
actionBar.setDisplayHomeAsUpEnabled(true);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
navigationView = (NavigationView) findViewById(R.id.navigation_view);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
menuItem.setChecked(true);
mDrawerLayout.closeDrawers();
switch (menuItem.getItemId()) {
case R.id.navigation_item_notification:
updateDisplay(new NotificationFragment());
break;
case R.id.navigation_item_user:
updateDisplay(new UserFragment());
break;
case R.id.navigation_item_log:
updateDisplay(new LogFragment());
break;
case R.id.navigation_sub_item_01:
updateDisplay(new AboutFragment());
break;
case R.id.navigation_sub_item_02:
{
if (btSocket!=null) //If the btSocket is busy
{
try
{
btSocket.close(); //close connection
}
catch (IOException e)
{ msg("Error");}
}
finish(); //return to the first layout
}
}
return true;
}
});
}
private void updateDisplay(Fragment fragment) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.frame_container, fragment).commit();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch (id) {
case android.R.id.home:
mDrawerLayout.openDrawer(GravityCompat.START);
return true;
case R.id.action_settings:
return true;
}
return super.onOptionsItemSelected(item);
}
private void Disconnect()
{
if (btSocket!=null) //If the btSocket is busy
{
try
{
btSocket.close(); //close connection
}
catch (IOException e)
{ msg("Error");}
}
finish(); //return to the first layout
}
// fast way to call Toast
private void msg(String s)
{
Toast.makeText(getApplicationContext(),s,Toast.LENGTH_LONG).show();
}
private class ConnectBT extends AsyncTask<Void, Void, Void> // UI thread
{
private boolean ConnectSuccess = true; //if it's here, it's almost connected
@Override
protected void onPreExecute()
{
progress = ProgressDialog.show(MainMenu.this, "Connecting...", "Please wait!!!"); //show a progress dialog
}
@Override
protected Void doInBackground(Void... devices) //while the progress dialog is shown, the connection is done in background
{
try
{
if (btSocket == null || !isBtConnected)
{
myBluetooth = BluetoothAdapter.getDefaultAdapter();//get the mobile bluetooth device
BluetoothDevice dispositivo = myBluetooth.getRemoteDevice(address);//connects to the device's address and checks if it's available
btSocket = dispositivo.createInsecureRfcommSocketToServiceRecord(myUUID);//create a RFCOMM (SPP) connection
BluetoothAdapter.getDefaultAdapter().cancelDiscovery();
btSocket.connect();//start connection
}
}
catch (IOException e)
{
ConnectSuccess = false;//if the try failed, you can check the exception here
}
return null;
}
@Override
protected void onPostExecute(Void result) //after the doInBackground, it checks if everything went fine
{
super.onPostExecute(result);
if (!ConnectSuccess)
{
msg("Connection Failed. Is it a SPP Bluetooth? Try again.");
finish();
}
else
{
msg("Connected.");
isBtConnected = true;
}
progress.dismiss();
}
}
UserFragment.Java
public class UserFragment extends ActionBarActivity {
private DBManager dbManager;
private ListView listView;
private SimpleCursorAdapter adapter;
final String[] from = new String[]{DatabaseHelper._ID,
DatabaseHelper.SUBJECT, DatabaseHelper.DESC};
final int[] to = new int[]{R.id.id, R.id.title, R.id.desc};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.user_fragment);
dbManager = new DBManager(this);
dbManager.open();
Cursor cursor = dbManager.fetch();
listView = (ListView) findViewById(R.id.list_view);
listView.setEmptyView(findViewById(R.id.empty));
adapter = new SimpleCursorAdapter(this, R.layout.activity_view_record, cursor, from, to, 0);
adapter.notifyDataSetChanged();
listView.setAdapter(adapter);
// OnCLickListiner For List Items
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long viewId) {
TextView idTextView = (TextView) view.findViewById(R.id.id);
TextView titleTextView = (TextView) view.findViewById(R.id.title);
TextView descTextView = (TextView) view.findViewById(R.id.desc);
String id = idTextView.getText().toString();
String title = titleTextView.getText().toString();
String desc = descTextView.getText().toString();
Intent modify_intent = new Intent(getApplicationContext(), ModifyCountryActivity.class);
modify_intent.putExtra("title", title);
modify_intent.putExtra("desc", desc);
modify_intent.putExtra("id", id);
startActivity(modify_intent);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.add_record) {
Intent add_mem = new Intent(this, AddCountryActivity.class);
startActivity(add_mem);
}
return super.onOptionsItemSelected(item);
}
如果我使用片段上UserFragment我對UserFragment了錯誤。但是,如果我在UserFragment上使用ActionBarActivity,我在MainMenu上遇到了錯誤。有人可以幫助我嗎?我的代碼有什麼問題?
請注意,有兩個'Fragment'類:'android.app.Fragment'和'android.support.v4.app.Fragment'。我看不到'import'語句,但是'required:Fragment found:UserFragment'的原因可能是您導入了一個,但使用了另一個。 – Mousa