我正在开发 WiFi Direct 应用程序。事实证明，当我打开 WiFi Direct 并启动程序时，该应用程序崩溃了。这是我的代码
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public class MainActivity extends Activity {
//For WiFi Direct
private WifiP2pManager mManager;
private Channel mChannel;
private IntentFilter mIntentFilter= new IntentFilter();
private boolean isWifiP2pEnabled = false;
private ArrayAdapter aa;
public void setIsWifiP2pEnabled(boolean isWifiP2pEnabled) {
isWifiP2pEnabled=isWifiP2pEnabled;
}
//End Wifi Direct
private Networking_input net;
private Networking_output net_out;
private Networking_files net_file;
private EditText inputData;
private Button sendParameters;
private Button peersSearch;
private ListView listview;
private TextView displayText;
private List<WifiP2pDevice> deviceList = new ArrayList<WifiP2pDevice>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//For Wifi Direct
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
//End Wifi Direct
inputData= (EditText) findViewById(R.id.editText1);
sendParameters=(Button) findViewById(R.id.button1);
peersSearch=(Button) findViewById(R.id.button2);
displayText=(TextView) findViewById(R.id.textView1);
listview=(ListView) findViewById(R.id.listView1);
aa=new ArrayAdapter<WifiP2pDevice>(this, android.R.layout.simple_list_item_1, deviceList);
listview.setAdapter(aa);
//Begin for WiFi Direct
mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
mChannel = mManager.initialize(this, getMainLooper(), null);
//End for WiFi Direct
peersSearch.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v)
{
discoverPeers();
}
});
listview.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int index,long arg3)
{
connectTo(deviceList.get(index));
}
});
sendParameters.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
net_out= new Networking_output();
String input=inputData.getText().toString();
net_out.execute(input);
net_file=new Networking_files();
net_file.execute();
}
});
}
BroadcastReceiver p2pStatusReceiver= new BroadcastReceiver()
{
@Override
public void onReceive(Context context, Intent intent) {
int state = intent.getIntExtra(
WifiP2pManager.EXTRA_WIFI_STATE,
WifiP2pManager.WIFI_P2P_STATE_DISABLED);
switch (state) {
case (WifiP2pManager.WIFI_P2P_STATE_ENABLED):
peersSearch.setEnabled(true);
break;
default:
peersSearch.setEnabled(false);
}
}
};
private void discoverPeers()
{
mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
@Override
public void onSuccess() {
Toast toast=Toast.makeText(MainActivity.this, "Discovery initiated", Toast.LENGTH_SHORT);
toast.show();
}
@Override
public void onFailure(int reason) {
Toast toast=Toast.makeText(MainActivity.this, "Discovery failed", Toast.LENGTH_SHORT);
toast.show();
}
});
}
BroadcastReceiver peerDiscoveryReceiver = new BroadcastReceiver()
{
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
@Override
public void onReceive(Context context, Intent intent)
{
mManager.requestPeers(mChannel, new PeerListListener() {
@Override
public void onPeersAvailable(WifiP2pDeviceList peers) {
deviceList.clear();
deviceList.addAll(peers.getDeviceList());
aa.notifyDataSetChanged();
}
});
}
};
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
private void connectTo(final WifiP2pDevice device)
{
WifiP2pConfig config=new WifiP2pConfig();
config.deviceAddress=device.deviceAddress;
mManager.connect(mChannel, config, new ActionListener() {
@Override
public void onSuccess() {
Toast toast=Toast.makeText(MainActivity.this, "Connected to " + device.deviceAddress.toString() , Toast.LENGTH_SHORT);
toast.show();
}
@Override
public void onFailure(int reason) {
Toast toast=Toast.makeText(MainActivity.this, "Connection Failed" , Toast.LENGTH_SHORT);
toast.show();
}
});
}
BroadcastReceiver connectionChangedReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent)
{
String ExtraKey=WifiP2pManager.EXTRA_NETWORK_INFO;
NetworkInfo networkinfo= (NetworkInfo)intent.getParcelableExtra(ExtraKey);
if(networkinfo.isConnected())
{
mManager.requestConnectionInfo(mChannel, new ConnectionInfoListener() {
public void onConnectionInfoAvailable(WifiP2pInfo info) {
if(info.groupFormed)
{
if(info.isGroupOwner)
{
Toast toast=Toast.makeText(MainActivity.this, "I am Group Owner" , Toast.LENGTH_SHORT);
toast.show();
}
else if(info.groupFormed)
{
Toast toast=Toast.makeText(MainActivity.this, "I am Group Client" , Toast.LENGTH_SHORT);
toast.show();
}
}
}
});
}
}
};
@Override
public void onResume()
{
super.onResume();
registerReceiver(peerDiscoveryReceiver, mIntentFilter);
registerReceiver(connectionChangedReceiver, mIntentFilter);
registerReceiver(p2pStatusReceiver, mIntentFilter);
}
@Override
public void onPause()
{
super.onPause();
unregisterReceiver(peerDiscoveryReceiver);
unregisterReceiver(connectionChangedReceiver);
unregisterReceiver(p2pStatusReceiver);
}
我从http://kurser.iha.dk/eit/itsmap/basic/MEIER/Professional%20Android%204%20All%20downloads/9781118102275%20PA4AD/Code%20Snippets/Chapter%2016/PA4AD_Ch16_WiFiDirect/src/com拿了一个代码/paad/wifidirect/WiFiDirectActivity.java
提前感谢您的帮助
UPD 清单文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.androidapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission
android:required="true"
android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission
android:required="true"
android:name="android.permission.CHANGE_WIFI_STATE"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.androidapp.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>