我正在使用BluetoothChat示例创建一个Android应用程序。
我需要将de bluetooth配置活动与聊天活动分开，因此，我有一个主要活动，其中包含用于启用/可发现蓝牙的按钮，以及另一个用于转到聊天活动的按钮。
这些功能与示例相同，但我将它们划分为2个活动。
问题是我需要从主活动调用SetupChat（）函数，在启用蓝牙时调用此函数。但是我在聊天活动中有这个功能，因为此活动中还有其他变量依赖于它。
那么，如何从主要活动中调用此函数？
我已经介绍了一些方法。如果函数是静态的，我可以毫无问题地调用它，但它是一个公共空白。我不能把这个函数放在一个简单的类中，因为它调用了“findviewbyid”函数，它需要在一个活动中。
那么，我怎么称它为？
我在这里举办了展位活动：
这是MainActivity：
public class BTActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final Button button1 = (Button) findViewById(R.id.boton1);
final Button button2 = (Button) findViewById(R.id.boton2);
final Button button4 = (Button) findViewById(R.id.boton4);
final Button button5 = (Button) findViewById(R.id.boton5);
button5.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
lanzarComunicacion (null);
}
});
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
Toast.makeText(this, "Bluetooth is not available", Toast.LENGTH_LONG).show();
finish();
return;
}
button2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
LanzarBusqueda(null);
}
});
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!mBluetoothAdapter.isDiscovering()) {
Context context = getApplicationContext();
CharSequence text = "MAKING YOUR DEVICE DISCOVERABLE";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
}
}
});
button4.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mBluetoothAdapter.disable();
//out.append("TURN_OFF BLUETOOTH");
Context context = getApplicationContext();
CharSequence text = "TURNING_OFF BLUETOOTH";
int duration = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(context, text, 15);
toast.show();
}
});
}
@Override
public void onStart() {
super.onStart();
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
else {
//HERE IS THE FIRST PLACE WHERE IT IS CALLED
if (mTransmission == null) BTCommunication.setupChat();
}
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case REQUEST_CONNECT_DEVICE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
connectDevice(data);
}
case REQUEST_ENABLE_BT:
// When the request to enable Bluetooth returns
if (resultCode == Activity.RESULT_OK) {
// Bluetooth is now enabled, so set up a chat session
//HERE IS CALLED
//BTCommunication.setupChat();
} else {
// User did not enable Bluetooth or an error occurred
Toast.makeText(this, R.string.bt_not_enabled_leaving, Toast.LENGTH_SHORT).show();
finish();
}
break;
}
}
private void connectDevice(Intent data) {
Toast.makeText(getApplicationContext(), "LLEGA", Toast.LENGTH_SHORT).show();
// Get the device MAC address
String address = data.getExtras().getString(DeviceListDialog.EXTRA_DEVICE_ADDRESS);
// Get the BluetoothDevice object
BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
// Attempt to connect to the device
mTransmission.connect(device);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.bt, menu);
return true;
}
/** Intent de llamada a activity de comunicacion*/
public void lanzarComunicacion (View view) {
Intent i = new Intent(this, BTCommunication.class);
startActivity(i);
}
/** Intent de llamada a dialogo de busqueda de dispositivos*/
public void LanzarBusqueda (View view) {
Intent serverintent = new Intent(this, DeviceListDialog.class);
startActivityForResult(serverintent, REQUEST_CONNECT_DEVICE);
}
}
/这是聊天活动：
public class BTCommunication extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.chat);
// Performing this check in onResume() covers the case in which BT was
// not enabled during onStart(), so we were paused to enable it...
// onResume() will be called when ACTION_REQUEST_ENABLE activity returns.
if (mTransmission != null) {
// Only if the state is STATE_NONE, do we know that we haven't started already
if (mTransmission.getState() == Transmission.STATE_NONE) {
// Start the Bluetooth chat services
mTransmission.start();
}
}
}
public void setupChat() {
// Initialize the array adapter for the conversation thread
mConversationArrayAdapter = new ArrayAdapter<String>(this, R.layout.message);
mConversationView = (ListView) findViewById(R.id.in);
mConversationView.setAdapter(mConversationArrayAdapter);
// Initialize the compose field with a listener for the return key
mOutEditText = (EditText) findViewById(R.id.edit_text_out);
mOutEditText.setOnEditorActionListener(mWriteListener);
// Initialize the send button with a listener that for click events
mSendButton = (Button) findViewById(R.id.button_send);
mSendButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// Send a message using content of the edit text widget
TextView view = (TextView) findViewById(R.id.edit_text_out);
String message = view.getText().toString();
sendMessage(message);
}
});
// Initialize the Transmission to perform bluetooth connections
mTransmission = new Transmission(this, mHandler);
// Initialize the buffer for outgoing messages
mOutStringBuffer = new StringBuffer("");
}
@Override
public void onDestroy() {
super.onDestroy();
// Stop the Bluetooth chat services
if (mTransmission != null) mTransmission.stop();
}
/**
* Sends a message.
* @param message A string of text to send.
*/
public void sendMessage(String message) {
// Check that we're actually connected before trying anything
if (mTransmission.getState() != Transmission.STATE_CONNECTED) {
Toast.makeText(this, R.string.not_connected, Toast.LENGTH_SHORT).show();
return;
}
// Check that there's actually something to send
if (message.length() > 0) {
// Get the message bytes and tell the BluetoothChatService to write
byte[] send = message.getBytes();
mTransmission.write(send);
// Reset out string buffer to zero and clear the edit text field
mOutStringBuffer.setLength(0);
mOutEditText.setText(mOutStringBuffer);
}
}
// The action listener for the EditText widget, to listen for the return key
private final TextView.OnEditorActionListener mWriteListener = new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView view, int actionId, KeyEvent event) {
// If the action is a key-up event on the return key, send the message
if (actionId == EditorInfo.IME_NULL && event.getAction() == KeyEvent.ACTION_UP) {
String message = view.getText().toString();
sendMessage(message);
}
return true;
}
};
private final void setStatus(int resId) {
final ActionBar actionBar = getActionBar();
actionBar.setSubtitle(resId);
}
private final void setStatus(CharSequence subTitle) {
final ActionBar actionBar = getActionBar();
actionBar.setSubtitle(subTitle);
}
// The Handler that gets information back from the Transmission
private final Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MESSAGE_STATE_CHANGE:
switch (msg.arg1) {
case Transmission.STATE_CONNECTED:
setStatus(getString(R.string.title_connected_to, mConnectedDeviceName));
mConversationArrayAdapter.clear();
break;
case Transmission.STATE_CONNECTING:
setStatus(R.string.title_connecting);
break;
case Transmission.STATE_LISTEN:
case Transmission.STATE_NONE:
setStatus(R.string.title_not_connected);
break;
}
break;
case MESSAGE_WRITE:
byte[] writeBuf = (byte[]) msg.obj;
// construct a string from the buffer
String writeMessage = new String(writeBuf);
mConversationArrayAdapter.add("Me: " + writeMessage);
break;
case MESSAGE_READ:
byte[] readBuf = (byte[]) msg.obj;
// construct a string from the valid bytes in the buffer
String readMessage = new String(readBuf, 0, msg.arg1);
mConversationArrayAdapter.add(mConnectedDeviceName+": " + readMessage);
break;
case MESSAGE_DEVICE_NAME:
// save the connected device's name
mConnectedDeviceName = msg.getData().getString(DEVICE_NAME);
Toast.makeText(getApplicationContext(), "Connected to " + mConnectedDeviceName, Toast.LENGTH_SHORT).show();
break;
case MESSAGE_TOAST:
Toast.makeText(getApplicationContext(), msg.getData().getString(TOAST), Toast.LENGTH_SHORT).show();
break;
}
}
};
}
答案 0 :(得分：0)
通常情况下，我有两种方法可以解决这个问题。
mainacvitity提供公共静态实例
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