Question

我无法弄清楚我写错了什么。这似乎是一个非常简单的案例，但我无法做到这一点。

1。 registerReceiver返回null，这有关系吗？ 2。接收者onReceive没有被调用 - 这是与registerReceiver相关联的给予空。

以下是我的活动中的代码

WifiManager mainWifiObj;
WifiScanReceiver wifiReceiver;

String wifis[];

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mainWifiObj = (WifiManager) getSystemService(Context.WIFI_SERVICE);
    wifiReceiver = new WifiScanReceiver();
    final Button button = (Button) findViewById(R.id.nextButton);
    button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            mainWifiObj.startScan();
        }
    });
}

protected void onStop() {
    unregisterReceiver(wifiReceiver);
    super.onStop();
}

protected void onStart() {
    registerReceiver(wifiReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
    //registerReceiver returning null
    super.onStart();
}

class WifiScanReceiver extends BroadcastReceiver {
    @SuppressLint("UseValueOf")
    public void onReceive(Context c, Intent intent) {
        List<ScanResult> wifiScanList = mainWifiObj.getScanResults();
        wifis = new String[wifiScanList.size()];
        Log.v(this.getClass().getName(), "wifiScanList.size() : "
                + wifiScanList.size());
        for (int i = 0; i < wifiScanList.size(); i++) {
            wifis[i] = ((wifiScanList.get(i)).toString());
            Log.v(this.getClass().getName(), wifiScanList.get(i).SSID);
        }
    }
}

这是我的清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.i2e1"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />


    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".FirstStateActivity"
            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>

</manifest>

我参考了http://www.tutorialspoint.com/android/android_wi_fi.htm 并尝试重现类似的代码，但它有效。

我在Android的Android模拟器中运行它。

Android：BroadcastReceiver onReceive没有被调用

0 个答案: