android 强制2G/3G或WIFI 优先上网
android开发中有时候需要设定程序连接网络优先 2G/3G 或 WIFI，下面片段代码给出设置方法：
public void setPreferredNetwork(int networkType) {ConnectivityManager connMgr = (ConnectivityManager) this.context.getSystemService("connectivity");if (networkType == NetworkType.TYPE_MOBILE) {//设为2G/3G网络优先，就算wifi连接到AP，系统仍然通过2G/3G访问网络connMgr.setNetworkPreference(0);} else if (networkType == NetworkType.TYPE_WIFI) {connMgr.setNetworkPreference(1);}WifiManager wifiMgr = (WifiManager) this.context.getSystemService("wifi");wifiMgr.disconnect();}