如果有人能幫助我,我將非常高興,因爲我是對象編程的新手。我的問題是:我正在用藍牙通信寫一些應用程序。我編寫了所有方法,並在MainActivity.class中的設備之間成功連接和傳輸數據。我也有一個SearchActivity.class它顯示列表中範圍內的所有設備,所以用戶可以選擇一個。設備然後通過意圖傳遞到MainActivity,其中連接開始。但由於我的應用程序的性質,我必須創建單獨的類,僅用於藍牙通信,稱爲BluetoothService.class。我將藍牙和其他東西的所有方法移至BluetoothService.class。 現在我甚至無法編譯我的項目,因爲我在創建Intent for SearchActivity時出錯,我也收到錯誤startActivityForResult和onActivityResult方法。無法啓動intent startActivityForResult類
第一錯誤是:構造意圖(BluetoothService,類)是未定義
第二錯誤:方法startActivityForResult(意向,INT)是未定義的類型BluetoothService
public void startConnection() {
// Create an intent for SearchActivity
Intent intent = new Intent(this, SearchActivity.class);
//start SearchActivity through intent and expect for result.
//The result is based on result code, which is REQUEST_DISCOVERY
startActivityForResult(intent, REQUEST_DISCOVERY);
}
當我從MainActivity調用方法startConnection()一切正常,但現在我沒有。我認爲問題在於,我無法從非活動類創建新的活動。
下一個錯誤是在onActivityResult方法:* RESULT_OK不能被解析爲一個變量*
//on ActivityResult method is called, when other activity returns result through intent!
//when user selected device in SearchActivity, result is passed through intent with //requestCode, resultCode (intent data + requestCode + resultCode)
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode != REQUEST_DISCOVERY) {
Log.d("Debug", ">>intent REQUEST_DISCOVERY failed!");
return;
}
if (resultCode != RESULT_OK) {
Log.d("Debug", ">>intent RESULT_OK failed!");
return;
}
Log.d("Debug", ">>onActivityResult!");
final BluetoothDevice device = data.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
Log.d(device.getName(), "Name of Selected Bluetoothdevice");
new Thread() {
public void run() {
//call connect function with device argument
connect(device);
};
}.start();
}
請告訴我怎樣才能解決這個問題。如果你需要更多的信息或代碼告訴我。謝謝。
public class SearchActivity extends ListActivity
{
//name of LxDevices, that will be shown on search
private String nameOfLxDevice = "DEBUG";
private Handler handler = new Handler();
/* Get Default Adapter */
private BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
/* Storage the BT devices */
private List<BluetoothDevice> devices = new ArrayList<BluetoothDevice>();
/* Discovery is Finished */
private volatile boolean discoveryFinished;
/* Start search device */
private Runnable discoveryWorker = new Runnable() {
public void run()
{
//To start discovering devices, simply call startDiscovery(). The process is asynchronous and the method will
//immediately return with a boolean indicating whether discovery has successfully started.
mBluetoothAdapter.startDiscovery();
Log.d("debug", ">>Starting Discovery");
for (;;)
{
if (discoveryFinished)
{
Log.d("debug", ">>Finished");
break;
}
try
{
Thread.sleep(100);
}
catch (InterruptedException e){}
}
}
};
/* when discovery is finished, this will be called */
//Your application must register a BroadcastReceiver for the ACTION_FOUND Intent in order to receive information about each device discovered.
//For each device, the system will broadcast the ACTION_FOUND Intent. This Intent carries the extra fields EXTRA_DEVICE and EXTRA_CLASS,
//containing a BluetoothDevice and a BluetoothClass, respectively
private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
/* get the search results */
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
//add it on List<BluetoothDevice>
devices.add(device);
//show found LxDevice on list
showDevices();
}
}
};
private BroadcastReceiver discoveryReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent)
{
/* unRegister Receiver */
Log.d("debug", ">>unregisterReceiver");
unregisterReceiver(mBroadcastReceiver);
unregisterReceiver(this);
discoveryFinished = true;
}
};
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search);
/* BT isEnable */
if (!mBluetoothAdapter.isEnabled())
{
Log.w("debug", ">>BT is disable!");
finish();
return;
}
/* Register Receiver*/
IntentFilter discoveryFilter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(discoveryReceiver, discoveryFilter);
IntentFilter foundFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadcastReceiver, foundFilter);
/* show a dialog "Scanning..." */
SamplesUtils.indeterminate(SearchActivity.this, handler, "Scanning for LX devices..", discoveryWorker, new OnDismissListener() {
public void onDismiss(DialogInterface dialog)
{
for (; mBluetoothAdapter.isDiscovering();) {
// Discovery is resource intensive. Make sure it isn't going on when you attempt to connect and pass your message.
mBluetoothAdapter.cancelDiscovery();
}
discoveryFinished = true;
}
}, true);
}
/* Show devices list */
private void showDevices()
{
//Create a list of strings
List<String> list = new ArrayList<String>();
for (int i = 0, size = devices.size(); i < size; ++i) {
StringBuilder b = new StringBuilder();
BluetoothDevice d = devices.get(i);
b.append(d.getName());
b.append('\n');
b.append(d.getAddress());
String s = b.toString();
list.add(s);
}
Log.d("debug", ">>showDevices");
final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list);
handler.post(new Runnable() {
public void run()
{
setListAdapter(adapter);
}
});
}
/* Select device */
protected void onListItemClick(ListView l, View v, int position, long id) {
Log.d("debug", ">>Click device");
Intent result = new Intent();
result.putExtra(BluetoothDevice.EXTRA_DEVICE, devices.get(position));
setResult(RESULT_OK, result);
finish();
}
}
在MainActivity我做:
// Initialize the BluetoothChatService to perform bluetooth connections
mBluetoothService = new BluetoothService(this);
構造函數,BluetoothService是:
public BluetoothService(Context context) {
}
連接方法:
protected void connect(BluetoothDevice device) {
try {
//Create a Socket connection: need the server's UUID number of registered
BluetoothSocket socket = null;
socket = device.createRfcommSocketToServiceRecord(MY_UUID);
socket.connect();
//Create temporary input and output stream
InputStreamtmpIn=socket.getInputStream();
OutputStream tmpOut = socket.getOutputStream();
//for use purposes
mmSocket = socket;
mmOutStream = tmpOut;
mmInStream = tmpIn;
tmpOut.write("Device connected..".getBytes());
//start Thread for receiving data over bluetooth
//dataReceiveThread.start();
} catch (IOException e) {
Log.e("Colibri2BB BT", "", e);
}
}
您是否在SearchActivity中調用startDiscovery? – 2013-04-24 07:24:02
您的BluettoothService類是否擴展Service?還必須顯示RESULT_OK屬於哪個類,比如SomeClass.RESULT_OK,如果RESULT_OK是靜態的。 – wrecker 2013-04-24 07:24:30
是的,我在SearchActivity中調用startDiscovery。 – anze87 2013-04-24 07:27:45