In this paper, we consider the event-triggered control problem for continuous-time switched linear systems. It is assumed that only the sampled information of system state and switching signal is available to the controller at each sampling instant. Based on a mode-dependent event-triggered transmission scheme, the closed-loop system is modeled as a switched system with delayed state and augmented switching signal. Then, an exponential stability condition, characterized by the dwell time and average dwell time of the switching signal, is obtained. The condition presents an extension of the multiple Lyapunov functional method based stability analysis for sampled-data control of nonswitched system. Consequently. the design methods for state-feedback controller gains and event-triggered parameters are then formulated by the properly selected quadratic Lyapunov functional. The analysis results are significant and also lead to an important step to study the event-triggered control for switched system. Finally, based on the definition of event-trigger efficiency, the effectiveness and improvement of the proposed approach are illustrated by two numerical examples.