共用方式為


Media.duration

[The feature associated with this page, Windows Media Player SDK, is a legacy feature. It has been superseded by MediaPlayer. MediaPlayer has been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer instead of Windows Media Player SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The duration property retrieves the duration of the current media item in seconds.

Syntax

player.currentMedia.duration

Possible Values

This property is a read-only Number ( double).

Remarks

If this property is used with a media item other than the one specified in Player.currentMedia, it may not contain a valid value.

To retrieve the duration for files that are not in the user's library, you must wait for Windows Media Player to open the file; that is, the current OpenState must equal MediaOpen. You can verify this by handling the Player.OpenStateChange event or by periodically checking the value of Player.openState.

For playlists, the duration of each media item can be retrieved when the individual media item is opened, rather than when the playlist is opened.

To retrieve the value of this property, read access to the library is required. For more information, see Library Access.

The following JScript example uses Media.duration to display the time remaining in the current media item. An HTML DIV element named RemTime displays the information. An HTML timer updates the text in the DIV element every second.

The following JScript code starts the timer:

// Execute the update() function at one-second intervals.
idTmr = window.setInterval("update()",1000);

The following JScript code stops the timer:

window.clearInterval(idTmr);

Use the Player.PlayStateChange event with a switch statement to determine when to start and stop the timer.

The following JScript code executes each time the timer calls the update function:

// Store the current position of the current media item.
var TimeNow = Player.controls.currentPosition;

// Display the time remaining information.
RemTime.innerHTML = "Seconds remaining: ";

// Subtract the current position from the duration of the current media.
// Use the Math.floor method to round the result down to the nearest integer.
RemTime.innerHTML += Math.floor(Player.currentMedia.duration - TimeNow);

Requirements

Requirement Value
Version
Windows Media Player version 7.0 or later.
DLL
Wmp.dll

See also

Media Object

Player.currentMedia

Player.PlayStateChange Event

Settings.mediaAccessRights

Settings.requestMediaAccessRights