內容

• 特性
• 信號
• 方法
• 詳細描述

Playlist QML 類型

用於指定要播放媒體的列錶。 更多...

import 語句：	import QtMultimedia 5.12
Since:	Qt 5.6

• 所有成員列錶，包括繼承成員

特性

• currentIndex : int
• currentItemsource : url
• error : enumeration
• errorString : string
• itemCount : int
• playbackMode : enumeration
• readOnly : bool

信號

• itemAboutToBeInserted ( start , end )
• itemAboutToBeRemoved ( start , end )
• itemChanged ( start , end )
• itemInserted ( start , end )
• itemRemoved ( start , end )
• loadFailed ()
• loaded ()

方法

• bool addItem ( source )
• bool addItems ( sources )
• bool clear ()
• bool insertItem ( index , source )
• bool insertItems ( index , sources )
• url itemSource ( index )
• load ( location , format )
• bool moveItem ( from , to )
• next ()
• int nextIndex ( steps )
• previous ()
• int previousIndex ( steps )
• bool removeItem ( index )
• bool removeItems (int start , int end )
• bool save ( location , format )
• shuffle ()

詳細描述

Playlist 類型提供播放媒體列錶的辦法采用 MediaPlayer , Audio and Video types. It can be used as a data source for view elements (such as ListView ) and other elements that interact with model data (such as Repeater). When used as a data model, each playlist item's source URL can be accessed using the source 角色。

Item {
    width: 400;
    height: 300;
    Audio {
        id: player;
        playlist: Playlist {
            id: playlist
            PlaylistItem { source: "song1.ogg"; }
            PlaylistItem { source: "song2.ogg"; }
            PlaylistItem { source: "song3.ogg"; }
        }
    }
    ListView {
        model: playlist;
        delegate: Text {
            font.pixelSize: 16;
            text: source;
        }
    }
    MouseArea {
        anchors.fill: parent;
        onPressed: {
            if (player.playbackState != Audio.PlayingState) {
                player.play();
            } else {
                player.pause();
            }
        }
    }
}
					

另請參閱 MediaPlayer , Audio ，和 Video .

特性文檔編製

currentIndex : int

This property holds the position of the current item in the playlist.

currentItemsource : url

This property holds the source URL of the current item in the playlist.

error : enumeration

此特性保持 Playlist 的錯誤條件。

值	描述
NoError	沒有錯誤
FormatError	格式錯誤。
FormatNotSupportedError	格式不支持。
NetworkError	網絡錯誤。
AccessDeniedError	訪問被拒錯誤。

errorString : string

This property holds a string describing the current error condition of the playlist.

itemCount : int

This property holds the number of items in the playlist.

playbackMode : enumeration

This property holds the order in which items in the playlist are played.

值	描述
CurrentItemOnce	The current item is played only once.
CurrentItemInLoop	The current item is played repeatedly in a loop.
Sequential	Playback starts from the current and moves through each successive item until the last is reached and then stops. The next item is a null item when the last one is currently playing.
Loop	Playback restarts at the first item after the last has finished playing.
Random	按隨機次序播放項。

readOnly : bool

This property indicates if the playlist can be modified.

信號文檔編製

itemAboutToBeInserted ( start , end )

This signal is emitted when items are to be inserted into the playlist at start and ending at end .

相應處理程序是 onItemAboutToBeInserted .

itemAboutToBeRemoved ( start , end )

This signal emitted when items are to be deleted from the playlist at start and ending at end .

相應處理程序是 onItemAboutToBeRemoved .

itemChanged ( start , end )

This signal is emitted after items have been changed in the playlist between start and end positions inclusive.

相應處理程序是 onItemChanged .

itemInserted ( start , end )

This signal is emitted after items have been inserted into the playlist. The new items are those between start and end 包括在內。

相應處理程序是 onItemInserted .

itemRemoved ( start , end )

This signal is emitted after items have been removed from the playlist. The removed items are those between start and end 包括在內。

相應處理程序是 onMediaRemoved .

loadFailed ()

This signal is emitted when the playlist loading failed. error and errorString can be checked for more information on the failure.

相應處理程序是 onLoadFailed .

loaded ()

This signal is emitted when the playlist loading succeeded.

相應處理程序是 onLoaded .

方法文檔編製

bool addItem ( source )

追加 source URL to the playlist.

返迴 true 若 source is added successfully.

bool addItems ( sources )

Appends the list of URLs in sources 到播放列錶。

返迴 true 若 sources are added successfully.

該方法在 Qt 5.7 引入。

bool clear ()

Removes all the items from the playlist.

Returns true if the operation is successful.

bool insertItem ( index , source )

插入 source URL to the playlist at the given index .

返迴 true 若 source is added successfully.

bool insertItems ( index , sources )

Inserts the list of URLs in sources to the playlist at the given index .

返迴 true 若 sources are added successfully.

該方法在 Qt 5.7 引入。

url itemSource ( index )

Returns the source URL of the item at the given index in the playlist.

load ( location , format )

Loads a playlist from the given location 。若 format is specified, it is used, otherwise the format is guessed from the location name and the data.

New items are appended to the playlist.

onloaded() is emitted if the playlist loads successfully, otherwise onLoadFailed() is emitted with error and errorString defined accordingly.

bool moveItem ( from , to )

移動項按索引位置 from 到索引位置 to .

Returns true if the item is moved successfully.

該方法在 Qt 5.7 引入。

next ()

Advances to the next item in the playlist.

int nextIndex ( steps )

Returns the index of the item in the playlist which would be current after calling next() steps times.

Returned value depends on the size of the playlist, the current position and the playback mode.

另請參閱 playbackMode and previousIndex() .

previous ()

Returns to the previous item in the playlist.

int previousIndex ( steps )

Returns the index of the item in the playlist which would be current after calling previous() steps times.

Returned value depends on the size of the playlist, the current position and the playback mode.

另請參閱 playbackMode and nextIndex() .

bool removeItem ( index )

Removed the item at the given index from the playlist.

返迴 true 若 source is removed successfully.

bool removeItems ( int start , int end )

Removes items in the playlist from start to end 包括在內。

Returns true if the items are removed successfully.

該方法在 Qt 5.7 引入。

bool save ( location , format )

Saves the playlist to the given location 。若 format is specified, it is used, otherwise the format is guessed from the location name.

Returns true if the playlist is saved successfully.

shuffle ()

Shuffles items in the playlist.