private IWXAPI mWeixinAPI;

  private void loginWithWeixin() {
    if (mWeixinAPI == null) {
      mWeixinAPI = WXAPIFactory.createWXAPI(this, WEIXIN_APP_ID, false);
    }

    if (!mWeixinAPI.isWXAppInstalled()) {
      //提醒用户没有按照微信
      return;
    }

    mWeixinAPI.registerApp(WEIXIN_APP_ID);

    SendAuth.Req req = new SendAuth.Req();
    req.scope = WEIXIN_SCOPE;
    req.state = WEIXIN_STATE;
    mWeixinAPI.sendReq(req);
  }

public class WXEntryActivity extends Activity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    handleIntent(getIntent());
  }

  @Override
  protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    handleIntent(intent);
  }

  private void handleIntent(Intent intent) {
    SendAuth.Resp resp = new SendAuth.Resp(intent.getExtras());
    if (resp.errCode == BaseResp.ErrCode.ERR_OK) {
      //用户同意
    }
  }
}

 E/WXEntryActivity(14288): onCreate...key:_wxapi_sendauth_resp_state xxx
    E/WXEntryActivity(14288): onCreate...key:_wxapi_sendauth_resp_token xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    E/WXEntryActivity(14288): onCreate...key:_mmessage_appPackage com.tencent.mm
    E/WXEntryActivity(14288): onCreate...key:_wxapi_baseresp_transaction null
    E/WXEntryActivity(14288): onCreate...key:_wxapi_sendauth_resp_lang zh_CN
    E/WXEntryActivity(14288): onCreate...key:_wxapi_command_type 1
    E/WXEntryActivity(14288): onCreate...key:_mmessage_content null
    E/WXEntryActivity(14288): onCreate...key:_wxapi_sendauth_resp_country null
    E/WXEntryActivity(14288): onCreate...key:_mmessage_checksum [B@426358e8
    E/WXEntryActivity(14288): onCreate...key:wx_token_key com.tencent.mm.openapi.token
    E/WXEntryActivity(14288): onCreate...key:_wxapi_sendauth_resp_url xxxxxxxxxxx
    E/WXEntryActivity(14288): onCreate...key:_mmessage_sdkVersion 570490883
    E/WXEntryActivity(14288): onCreate...key:_wxapi_baseresp_errcode 0
    E/WXEntryActivity(14288): onCreate...key:_wxapi_baseresp_errstr null
    E/WXEntryActivity(14288): onCreate...key:_wxapi_baseresp_openId null