该方法html_text()(来自 R Package rvest)连接节点及其所有子节点的文本。我只想提取父亲的文字。
对于下面的例子,html_text()给出HELLO GOODBYE。
我只想得到GOODBYE。我怎么才能得到它?
<div class="joke">
<div class="div_inside">
<div class="title_inside">
<a class="link" href="sompage.htm">HELLO</a>
</div>
</div>
GOODBYE
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wifi连接建立后我想做点什么。我有一个 BroadcastReceiver 可以完美地接收 NETWORK_STATE_CHANGED_ACTION 和 SCAN_RESULTS_AVAILABLE_ACTION,但不是 SUPPLICANT_CONNECTION_CHANGE_ACTION。这个更难测试:我为此关闭/打开路由器。
protected void onCreate(Bundle savedInstanceState) {
receiverWifi = new WifiReceiver();
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION);
intentFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
intentFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
registerReceiver(receiverWifi, intentFilter);
//...
}
class WifiReceiver extends BroadcastReceiver {
public void onReceive(Context c, Intent intent) {
final String action = intent.getAction();
Log.d("mhp","*BroadcastReceiver: " + action")}
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和 Manifyingt.xml
<application
a..
<activity
android:name=".MainActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.net.wifi.SCAN_RESULTS" />
<action android:name="android.net.wifi.supplicant.CONNECTION_CHANGE" />
<action android:name="android.net.wifi.STATE_CHANGE" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
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和 AndroidManifest.xml:
<application
a..
<activity
android:name=".MainActivity" …Run Code Online (Sandbox Code Playgroud)