如何在Android 3.x或4.x上以编程方式配置静态IP地址，网络掩码，网关

Question

它可以在Android 2.3之前运行。但是，在更高的API级别上没有运气。例如，我把设置

android.provider.Settings.System.putString(getContentResolver(), android.provider.Settings.System.WIFI_USE_STATIC_IP, "1");        
android.provider.Settings.System.putString(getContentResolver(), android.provider.Settings.System.WIFI_STATIC_IP, "192.168.0.100");
android.provider.Settings.System.putString(getContentResolver(), android.provider.Settings.System.WIFI_STATIC_NETMASK, "255.255.255.0");
android.provider.Settings.System.putString(getContentResolver(), android.provider.Settings.System.WIFI_STATIC_DNS1, "192.168.0.254");
android.provider.Settings.System.putString(getContentResolver(), android.provider.Settings.System.WIFI_STATIC_GATEWAY, "192.168.0.254");

但是我回过头来检查：

Setting --> Wi-Fi --> Long Press Access Point SSID --> Modify Network --> check Show advanced options

该IP Settings字段仍然说明，DHCP但没有Static。

我确实可以android.provider.Settings.System.getString()用来找回设定的东西。证明该设置保存在某个地方，但是系统只是忽略它。

系统使用除android.provider.Settings.SystemAndroid 3.x和4.x上的设置以外的其他设置，因为该设置是根据访问点SSID设置的。我可以像在Android 2.3上一样修改一个SSID上的设置吗？

Answer 1

我意识到在3.x或4.x上没有针对每个SSID的那些设置的API。因此，我检查了源代码，发现每个SSID的配置都存储在android.net.wifi.WifiConfiguration其中，该配置是从中获取的android.net.wifi.WifiManager。

在下面的代码，IpAssignment是一个枚举，无论是STAIC，DHCP或NONE。并且linkProperties是对象存储的IP地址，网关，DNS等。

linkAddress 是IP地址，其网络掩码为prefixLength（网络掩码中的多少位1）。

mRoutes是ArrayList的RouteInfo，可以指示网关。

mDnses 是ArrayList的InetAddress对DNS。

首先，使用WifiConfigurationSSID 获取当前配置

WifiConfiguration wifiConf = null;
WifiManager wifiManager = (WifiManager)getSystemService(Context.WIFI_SERVICE);
WifiInfo connectionInfo = wifiManager.getConnectionInfo();
List<WifiConfiguration> configuredNetworks = wifiManager.getConfiguredNetworks();        
for (WifiConfiguration conf : configuredNetworks){
    if (conf.networkId == connectionInfo.getNetworkId()){
        wifiConf = conf;
        break;              
    }
}

由于IpAssignment和linkProperties被隐藏，因此可以从反射中获取对象。

以下方法可以在SSID WifiConfiguration上设置声明的IP地址设置：

    public static void setIpAssignment(String assign , WifiConfiguration wifiConf)
    throws SecurityException, IllegalArgumentException, NoSuchFieldException, IllegalAccessException{
        setEnumField(wifiConf, assign, "ipAssignment");     
    }

    public static void setIpAddress(InetAddress addr, int prefixLength, WifiConfiguration wifiConf)
    throws SecurityException, IllegalArgumentException, NoSuchFieldException, IllegalAccessException,
    NoSuchMethodException, ClassNotFoundException, InstantiationException, InvocationTargetException{
        Object linkProperties = getField(wifiConf, "linkProperties");
        if(linkProperties == null)return;
        Class laClass = Class.forName("android.net.LinkAddress");
        Constructor laConstructor = laClass.getConstructor(new Class[]{InetAddress.class, int.class});
        Object linkAddress = laConstructor.newInstance(addr, prefixLength);

        ArrayList mLinkAddresses = (ArrayList)getDeclaredField(linkProperties, "mLinkAddresses");
        mLinkAddresses.clear();
        mLinkAddresses.add(linkAddress);        
    }

    public static void setGateway(InetAddress gateway, WifiConfiguration wifiConf)
    throws SecurityException, IllegalArgumentException, NoSuchFieldException, IllegalAccessException, 
    ClassNotFoundException, NoSuchMethodException, InstantiationException, InvocationTargetException{
        Object linkProperties = getField(wifiConf, "linkProperties");
        if(linkProperties == null)return;
        Class routeInfoClass = Class.forName("android.net.RouteInfo");
        Constructor routeInfoConstructor = routeInfoClass.getConstructor(new Class[]{InetAddress.class});
        Object routeInfo = routeInfoConstructor.newInstance(gateway);

        ArrayList mRoutes = (ArrayList)getDeclaredField(linkProperties, "mRoutes");
        mRoutes.clear();
        mRoutes.add(routeInfo);
    }

    public static void setDNS(InetAddress dns, WifiConfiguration wifiConf)
    throws SecurityException, IllegalArgumentException, NoSuchFieldException, IllegalAccessException{
        Object linkProperties = getField(wifiConf, "linkProperties");
        if(linkProperties == null)return;

        ArrayList<InetAddress> mDnses = (ArrayList<InetAddress>)getDeclaredField(linkProperties, "mDnses");
        mDnses.clear(); //or add a new dns address , here I just want to replace DNS1
        mDnses.add(dns); 
    }

    public static Object getField(Object obj, String name)
    throws SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException{
        Field f = obj.getClass().getField(name);
        Object out = f.get(obj);
        return out;
    }

    public static Object getDeclaredField(Object obj, String name)
    throws SecurityException, NoSuchFieldException,
    IllegalArgumentException, IllegalAccessException {
        Field f = obj.getClass().getDeclaredField(name);
        f.setAccessible(true);
        Object out = f.get(obj);
        return out;
    }  

    private static void setEnumField(Object obj, String value, String name)
    throws SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException{
        Field f = obj.getClass().getField(name);
        f.set(obj, Enum.valueOf((Class<Enum>) f.getType(), value));
    }

之后，我可以WifiConfiguration为此SSID进行设置和更新。

    try{
        setIpAssignment("STATIC", wifiConf); //or "DHCP" for dynamic setting
        setIpAddress(InetAddress.getByName("192.168.0.100"), 24, wifiConf);
        setGateway(InetAddress.getByName("4.4.4.4"), wifiConf);
        setDNS(InetAddress.getByName("4.4.4.4"), wifiConf);
        wifiManager.updateNetwork(wifiConf); //apply the setting
            wifiManager.saveConfiguration(); //Save it
    }catch(Exception e){
        e.printStackTrace();
    }

编辑：对不起，我没有检查具有Android 4.x的silmilar UI的Android 3.x设备。在Android 3.x中，网关存储在mGateways中linkProperties。 mGateways是Arraylist类型InetAddress。因此，以下操作应在Android 3.x中起作用。

public static void setGateway(InetAddress gateway, WifiConfiguration wifiConf)
        throws SecurityException, IllegalArgumentException, NoSuchFieldException, IllegalAccessException, 
        ClassNotFoundException, NoSuchMethodException, InstantiationException, InvocationTargetException{
            Object linkProperties = getField(wifiConf, "linkProperties");
            if(linkProperties == null)return;
            ArrayList mGateways = (ArrayList)getDeclaredField(linkProperties, "mGateways");
            mGateways.clear();
            mGateways.add(gateway);
        }

EDIT2：所述方法setIpAddress，setGateway，setDNS应当被输入作为InetAddress类型。