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我正在學習android api的過程。然而，當我試圖獲取有關無線網絡信息我的程序意外關閉：當我嘗試getConnectionInfo時，程序意外關閉
這裏是代碼：
package com.example.helloandroid;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.content.BroadcastReceiver;
import android.content.Context;
public class HelloAndroid extends Activity {
/** Called when the activity is first created. */
WifiManager wifi;
BroadcastReceiver receiver;
TextView textStatus;
Button buttonScan;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TextView tv = new TextView(this);
tv.setText("Hello, Android");
setContentView(tv);
wifi = (WifiManager)getSystemService(Context.WIFI_SERVICE);
// WifiInfo info = wifi.getConnectionInfo();
// tv.append("\n\nWiFi Status: " + info.toString());
}
}
上面運行的代碼，但只要我取消對該行： WifiInfo info = wifi.getConnectionInfo();
它說我的程序意外關閉。我不確定我做錯了什麼。任何幫助，將不勝感激。
我正在使用模擬器。
感謝
更新：如果我寫出來的WiFi OBJ：
wifi = (WifiManager)getSystemService(Context.WIFI_SERVICE);
tv.append(wifi.toString());
應用程序運行和電視說：
android.net.wifi.
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UPDATE： logcat的：
09-22 14:56:51.387: ERROR/AndroidRuntime(408): FATAL EXCEPTION: main
09-22 14:56:51.387: ERROR/AndroidRuntime(408): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.helloandroid/com.example.helloandroid.HelloAndroid}: java.lang.SecurityException: WifiService: Neither user 10034 nor current process has android.permission.ACCESS_WIFI_STATE.
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.os.Handler.dispatchMessage(Handler.java:99)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.os.Looper.loop(Looper.java:123)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.app.ActivityThread.main(ActivityThread.java:3683)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at java.lang.reflect.Method.invokeNative(Native Method)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at java.lang.reflect.Method.invoke(Method.java:507)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at dalvik.system.NativeStart.main(Native Method)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): Caused by: java.lang.SecurityException: WifiService: Neither user 10034 nor current process has android.permission.ACCESS_WIFI_STATE.
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.os.Parcel.readException(Parcel.java:1322)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.os.Parcel.readException(Parcel.java:1276)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.net.wifi.IWifiManager$Stub$Proxy.getConnectionInfo(IWifiManager.java:591)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.net.wifi.WifiManager.getConnectionInfo(WifiManager.java:605)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at com.example.helloandroid.HelloAndroid.onCreate(HelloAndroid.java:35)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
09-22 14:56:51.387: ERROR/AndroidRuntime(408): ... 11 more
Logcat輸出會有幫助 – Knickedi