1.AndroidManifest.xml里添加权限：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"></uses-permission>

2.

/**
  * 开启系统设置里的移动网络
  */
 public final void setMobileNetEnable(){
  ConnectivityManager mConnectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

  Object[] arg = null;
  try {
   boolean isMobileDataEnable = invokeMethod("getMobileDataEnabled", arg);
   if(!isMobileDataEnable){
    invokeBooleanArgMethod("setMobileDataEnabled", true);
   }
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

public boolean invokeMethod(String methodName,
            Object[]  arg) throws Exception {
     
     ConnectivityManager mConnectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

        Class ownerClass = mConnectivityManager.getClass();

        Class[]  argsClass = null;
        if (arg != null) {
            argsClass = new Class[1];
            argsClass[0] = arg.getClass();
        }

        Method method = ownerClass.getMethod(methodName, argsClass);
       
        Boolean isOpen = (Boolean) method.invoke(mConnectivityManager, arg);

        return isOpen;
    }
    
     public Object invokeBooleanArgMethod(String methodName,
                boolean value) throws Exception {
     
      ConnectivityManager mConnectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

            Class ownerClass = mConnectivityManager.getClass();

            Class[]  argsClass = new Class[1];
                argsClass[0] = boolean.class;

            Method method = ownerClass.getMethod(methodName,argsClass);

            return method.invoke(mConnectivityManager, value);
        }