Android MediaPlayer基本知识
Valid and invalid states
| Method Name | Valid Sates | Invalid States | Comments |
| attachAuxEffect | {Initialized, Prepared, Started, Paused, Stopped, PlaybackCompleted} | {Idle, Error} | This method must be called after setDataSource. Calling it does not change the object state. |
| getAudioSessionId | any | {} | This method can be called in any state and calling it does not change the object state. |
| getCurrentPosition | {Idle, Initialized, Prepared, Started, Paused, Stopped, PlaybackCompleted} | {Error} | Successful invoke of this method in a valid state does not change the state. Calling this method in an invalid state transfers the object to theError state. |
| getDuration | {Prepared, Started, Paused, Stopped, PlaybackCompleted} | {Idle, Initialized, Error} | Successful invoke of this method in a valid state does not change the state. Calling this method in an invalid state transfers the object to theError state. |
| getVideoHeight | {Idle, Initialized, Prepared, Started, Paused, Stopped, PlaybackCompleted} | {Error} | Successful invoke of this method in a valid state does not change the state. Calling this method in an invalid state transfers the object to theError state. |
| getVideoWidth | {Idle, Initialized, Prepared, Started, Paused, Stopped, PlaybackCompleted} | {Error} | Successful invoke of this method in a valid state does not change the state. Calling this method in an invalid state transfers the object to theError state. |
| isPlaying | {Idle, Initialized, Prepared, Started, Paused, Stopped, PlaybackCompleted} | {Error} | Successful invoke of this method in a valid state does not change the state. Calling this method in an invalid state transfers the object to theError state. |
| pause | {Started, Paused} | {Idle, Initialized, Prepared, Stopped, PlaybackCompleted, Error} | Successful invoke of this method in a valid state transfers the object to thePaused state. Calling this method in an invalid state transfers the object to theError state. |
| prepare | {Initialized, Stopped} | {Idle, Prepared, Started, Paused, PlaybackCompleted, Error} | Successful invoke of this method in a valid state transfers the object to thePrepared state. Calling this method in an invalid state throws an IllegalStateException. |
| prepareAsync | {Initialized, Stopped} | {Idle, Prepared, Started, Paused, PlaybackCompleted, Error} | Successful invoke of this method in a valid state transfers the object to thePreparing state. Calling this method in an invalid state throws an IllegalStateException. |
| release | any | {} | After release(), the object is no longer available. |
| reset | {Idle, Initialized, Prepared, Started, Paused, Stopped, PlaybackCompleted, Error} | {} | After reset(), the object is like being just created. |
| seekTo | {Prepared, Started, Paused, PlaybackCompleted} | {Idle, Initialized, Stopped, Error} | Successful invoke of this method in a valid state does not change the state. Calling this method in an invalid state transfers the object to theError state. |
| setAudioSessionId | {Idle} | {Initialized, Prepared, Started, Paused, Stopped, PlaybackCompleted, Error} | This method must be called in idle state as the audio session ID must be known before calling setDataSource. Calling it does not change the object state. |
| setAudioStreamType | {Idle, Initialized, Stopped, Prepared, Started, Paused, PlaybackCompleted} | {Error} | Successful invoke of this method does not change the state. In order for the target audio stream type to become effective, this method must be called before prepare() or prepareAsync(). |
| setAuxEffectSendLevel | any | {} | Calling this method does not change the object state. |
| setDataSource | {Idle} | {Initialized, Prepared, Started, Paused, Stopped, PlaybackCompleted, Error} | Successful invoke of this method in a valid state transfers the object to theInitialized state. Calling this method in an invalid state throws an IllegalStateException. |
| setDisplay | any | {} | This method can be called in any state and calling it does not change the object state. |
| setSurface | any | {} | This method can be called in any state and calling it does not change the object state. |
| setLooping | {Idle, Initialized, Stopped, Prepared, Started, Paused, PlaybackCompleted} | {Error} | Successful invoke of this method in a valid state does not change the state. Calling this method in an invalid state transfers the object to theError state. |
| isLooping | any | {} | This method can be called in any state and calling it does not change the object state. |
| setOnBufferingUpdateListener | any | {} | This method can be called in any state and calling it does not change the object state. |
| setOnCompletionListener | any | {} | This method can be called in any state and calling it does not change the object state. |
| setOnErrorListener | any | {} | This method can be called in any state and calling it does not change the object state. |
| setOnPreparedListener | any | {} | This method can be called in any state and calling it does not change the object state. |
| setOnSeekCompleteListener | any | {} | This method can be called in any state and calling it does not change the object state. |
| setScreenOnWhilePlaying</> | any | {} | This method can be called in any state and calling it does not change the object state. |
| setVolume | {Idle, Initialized, Stopped, Prepared, Started, Paused, PlaybackCompleted} | {Error} | Successful invoke of this method does not change the state. |
| setWakeMode | any | {} | This method can be called in any state and calling it does not change the object state. |
| start | {Prepared, Started, Paused, PlaybackCompleted} | {Idle, Initialized, Stopped, Error} | Successful invoke of this method in a valid state transfers the object to theStarted state. Calling this method in an invalid state transfers the object to theError state. |
| stop | {Prepared, Started, Stopped, Paused, PlaybackCompleted} | {Idle, Initialized, Error} | Successful invoke of this method in a valid state transfers the object to theStopped state. Calling this method in an invalid state transfers the object to theError state. |
如何获取当前播放视频的总长度和当前播放时间？
1) 根据上表的状态要求调用mediaplayer.getDuration()得到总时长
2) 创建一个新线程，每秒调用mediaplayer.getCurrentPosition ()获取当前播放时间