使用android Wi-Fi Direct API时出现问题:mChannel=mManager.initialize()
这是我的第一篇帖子,希望能做好。我正在尝试使用新的android技术Wi-Fi Direct创建一个应用程序。为此,我遵循了您可以在中找到的教程: 它真的很有用,但是当我复制代码时,出现了一些错误。与步骤3完全一致:使用android Wi-Fi Direct API时出现问题:mChannel=mManager.initialize(),android,channel,wifi-direct,Android,Channel,Wifi Direct,这是我的第一篇帖子,希望能做好。我正在尝试使用新的android技术Wi-Fi Direct创建一个应用程序。为此,我遵循了您可以在中找到的教程: 它真的很有用,但是当我复制代码时,出现了一些错误。与步骤3完全一致: WifiP2pManager mManager; Channel mChannel; BroadcastReceiver mReceiver; ... @Override protected void onCreate(Bundle savedInstanceState){
WifiP2pManager mManager;
Channel mChannel;
BroadcastReceiver mReceiver;
...
@Override
protected void onCreate(Bundle savedInstanceState){
...
mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
mChannel = mManager.initialize(this, getMainLooper(), null);
mReceiver = new WiFiDirectBroadcastReceiver(manager, channel, this);
...
}
错误在线:
mChannel = mManager.initialize(this, getMainLooper(), null);
错误消息是:
类型不匹配:无法从WifiPesManager.Channel转换到Channel
建议您制作这样的演员阵容:
mcchannel=(Channel)mManager.initialize(this,getMainLooper(),null)
但是,当我为此更改代码时,在运行应用程序时出现另一个错误:
10-25 12:08:34.845:E/AndroidRuntime(26634):java.lang.RuntimeException:无法启动活动组件信息{android.nacho.WifiDirect/android.nacho.WifiDirect.WifiDirect}:java.lang.ClassCastException:android.net.wifi.p2p.WifiP2pManager$Channel无法强制转换为java.nio.channels.channels
只需添加代码的其余部分,这正是它在教程中的显示方式,但以防我要添加活动和广播类:
package android.nacho.WifiDirect;
import java.nio.channels.Channel;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.wifi.p2p.WifiP2pManager;
import android.widget.Toast;
/**
* A BroadcastReceiver that notifies of important Wi-Fi p2p events.
*/
public class WiFiBroadcastReceiver extends BroadcastReceiver {
private WifiP2pManager manager;
private Channel channel;
private WifiDirect activity;
//For toast, add also context
private Context context;
public WiFiBroadcastReceiver(WifiP2pManager manager, Channel channel, WifiDirect activity, Context context) {
super();
this.manager = manager;
this.channel = channel;
this.activity = activity;
this.context= context;
}
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
// Check to see if Wi-Fi is enabled and notify appropriate activity
int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
Toast.makeText(context, "Wi-Fi Direct is enable", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(context, "Wi-Fi Direct is not enable", Toast.LENGTH_LONG).show();
}
} else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
// Call WifiP2pManager.requestPeers() to get a list of current peers
} else if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
// Respond to new connection or disconnections
} else if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
// Respond to this device's wifi state changing
}
}
}
1-主要活动:
package android.nacho.WifiDirect;
import java.nio.channels.Channel;
import android.net.wifi.p2p.WifiP2pManager;
import android.os.Bundle;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.IntentFilter;
import android.view.Menu;
public class WifiDirect extends Activity {
WifiP2pManager mManager;
Channel mChannel;
BroadcastReceiver mReceiver;
IntentFilter mIntentFilter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_wifi_direct);
//To register the BroadastReceiver
mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
mChannel = (Channel) mManager.initialize(this, getMainLooper(), null); //It was necessary to make a cast (Channel)
mReceiver = new WiFiBroadcastReceiver(mManager, mChannel, this, this);
//To define the filter in the BroadcastReceiver
mIntentFilter = new IntentFilter();
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);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_wifi_direct, menu);
return true;
}
//
@Override
protected void onResume() {
super.onResume();
registerReceiver(mReceiver, mIntentFilter);
}
// unregister the broadcast receiver
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(mReceiver);
}
}
2-广播类:
package android.nacho.WifiDirect;
import java.nio.channels.Channel;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.wifi.p2p.WifiP2pManager;
import android.widget.Toast;
/**
* A BroadcastReceiver that notifies of important Wi-Fi p2p events.
*/
public class WiFiBroadcastReceiver extends BroadcastReceiver {
private WifiP2pManager manager;
private Channel channel;
private WifiDirect activity;
//For toast, add also context
private Context context;
public WiFiBroadcastReceiver(WifiP2pManager manager, Channel channel, WifiDirect activity, Context context) {
super();
this.manager = manager;
this.channel = channel;
this.activity = activity;
this.context= context;
}
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
// Check to see if Wi-Fi is enabled and notify appropriate activity
int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
Toast.makeText(context, "Wi-Fi Direct is enable", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(context, "Wi-Fi Direct is not enable", Toast.LENGTH_LONG).show();
}
} else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
// Call WifiP2pManager.requestPeers() to get a list of current peers
} else if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
// Respond to new connection or disconnections
} else if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
// Respond to this device's wifi state changing
}
}
}
3安卓清单:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="android.nacho.WifiDirect"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="15" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".WifiDirect"
android:label="@string/title_activity_wifi_direct" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
非常感谢你的帮助 您使用的频道类来自错误的包 导入android.net.wifi.p2p.WifiP2pManager.Channel代码> 而不是
import java.nio.channels.Channel代码>非常感谢。这就是问题所在。真是愚蠢的错误,而且只是为了信任Eclipse的提示