/// <summary>
/// 播放快进（每次快进 FramesStep）
/// </summary>
public void Forward()
{
int err = 0;
StringBuilder buf = new StringBuilder(1000);
TimeFormat tf = timeFormat;
if (deviceID > 0)
{
if ((devCaps & DevCaps.CanShowVideo) == DevCaps.CanShowVideo)
{
if (GetLength() - GetPosition() <= framesStep)
{
MCI_GENERIC_PARMS gen = new MCI_GENERIC_PARMS();
Pause();
err = mciSendCommandA(deviceID, MCI_SEEK, MCI_SEEK_TO_END | MCI_WAIT, ref gen);
if (err != 0)
{
mciGetErrorStringA(err, buf, 1000);
//throw new ApplicationException(buf.ToString());
}
Play();
}
else
{
MCI_DGV_STEP_PARMS step = new MCI_DGV_STEP_PARMS();
Pause();
if (timeFormat != TimeFormat.Frames)
{
timeFormat = TimeFormat.Frames;
MciSet(0, MCI_FORMAT_FRAMES, MCI_SET_TIME_FORMAT);
}
step.dwFrames = framesStep;
err = mciSendCommandA(deviceID, MCI_STEP, MCI_WAIT | MCI_DGV_STEP_FRAMES, ref step);
if (err != 0)
{
mciGetErrorStringA(err, buf, 1000);
//throw new ApplicationException(buf.ToString());
}
if (tf != TimeFormat.Frames)
{
timeFormat = tf;
MciSet(0, (int)tf, MCI_SET_TIME_FORMAT);
}
Play();
}
}
else
{
if (timeFormat != TimeFormat.MilliSeconds)
{
timeFormat = TimeFormat.MilliSeconds;
MciSet(0, MCI_FORMAT_MILLISECONDS, MCI_SET_TIME_FORMAT);
}
SeekToAny(GetPosition() + framesStep);
if (tf != TimeFormat.MilliSeconds)
{
timeFormat = tf;
MciSet(0, (int)tf, MCI_SET_TIME_FORMAT);
}
}
}
}
private static extern int mciSendCommandA(
Int32 wDeviceID,
UInt32 uMessage,
Int32 dwParam,
ref MCI_DGV_STEP_PARMS Any);
