In this note, we discuss the modeling and control of a class of Ito stochastic networked control systems (NCSs) with packet dropouts that are subject to time-varying sampling. The system under consideration is first modeled as a continuous-time system with input delay that is subject to double randomness via the input-delay approach. Then, by assuming the packet drop rate and recurring to the celebrated formula of total probability, an equivalent model which takes full advantage of probability distribution characteristics of both packet dropouts and sampling periods is established. In particular, the probability distribution values of the stochastic delay taking values in two given intervals can be explicitly obtained, which is of crucial importance to model and analyze the actual problem in NCSs. Based on that, robustly exponentially mean-square stability of the system with an H-infinity performance is guaranteed, an H-infinity controller design procedure is then proposed. Finally, a numerical simulation example is exploited to show the effectiveness and applicability of the results derived and some less conservative results are obtained.