本主題將說明針對 Unity 遊戲使用 Play 遊戲服務的遊戲進度存檔。
事前準備
顯示遊戲進度存檔 UI
呼叫以下內容,即可顯示標準 UI,用於選取或建立遊戲進度存檔項目:
void ShowSelectUI() {
uint maxNumToDisplay = 5;
bool allowCreateNew = false;
bool allowDelete = true;
ISavedGameClient savedGameClient = PlayGamesPlatform.Instance.SavedGame;
savedGameClient.ShowSelectSavedGameUI("Select saved game",
maxNumToDisplay,
allowCreateNew,
allowDelete,
OnSavedGameSelected);
}
public void OnSavedGameSelected (SelectUIStatus status, ISavedGameMetadata game) {
if (status == SelectUIStatus.SavedGameSelected) {
// handle selected game save
} else {
// handle cancel or error
}
}
開啟遊戲進度存檔
若要讀取遊戲進度存檔,或在存檔中寫入資料,需要先開啟遊戲進度存檔。由於遊戲進度存檔狀態會在裝置本機製作快取,並將存檔狀態儲存到雲端上,因此儲存資料狀態可能會發生衝突。如果裝置嘗試把狀態儲存到雲端,但是其他裝置已經在目前位於雲端的資料中寫入資料,那麼就會發生衝突。開啟遊戲進度存檔資料時,就需要解決這類衝突。
能夠解決衝突的開放式方法有 2 種,第一種是 OpenWithAutomaticConflictResolution,這個方法可以接受標準解決方案策略類型,並自動解決衝突。另一種方法是 OpenWithManualConflictResolution,這個方法接受回呼方法,以便手動解決衝突。
如果想進一步瞭解這些方法,請參閱 GooglePlayGames/BasicApi/SavedGame/ISavedGameClient.cs。
void OpenSavedGame(string filename) {
ISavedGameClient savedGameClient = PlayGamesPlatform.Instance.SavedGame;
savedGameClient.OpenWithAutomaticConflictResolution(filename, DataSource.ReadCacheOrNetwork,
ConflictResolutionStrategy.UseLongestPlaytime, OnSavedGameOpened);
}
public void OnSavedGameOpened(SavedGameRequestStatus status, ISavedGameMetadata game) {
if (status == SavedGameRequestStatus.Success) {
// handle reading or writing of saved game.
} else {
// handle error
}
}
寫入遊戲進度存檔
開啟遊戲進度存檔的檔案後,可以藉由在此檔案寫入資料儲存遊戲狀態。做法是呼叫 CommitUpdate。CommitUpdate 提供四種參數:
- 系統會向其中一種 Open 呼叫傳遞回呼,而需要傳遞給這個回呼的遊戲進度存檔中繼資料。
- 中繼資料的更新內容。
- 實際使用的資料位元組陣列
- 修訂完成後所呼叫的回呼。
void SaveGame (ISavedGameMetadata game, byte[] savedData, TimeSpan totalPlaytime) {
ISavedGameClient savedGameClient = PlayGamesPlatform.Instance.SavedGame;
SavedGameMetadataUpdate.Builder builder = new SavedGameMetadataUpdate.Builder();
builder = builder
.WithUpdatedPlayedTime(totalPlaytime)
.WithUpdatedDescription("Saved game at " + DateTime.Now());
if (savedImage != null) {
// This assumes that savedImage is an instance of Texture2D
// and that you have already called a function equivalent to
// getScreenshot() to set savedImage
// NOTE: see sample definition of getScreenshot() method below
byte[] pngData = savedImage.EncodeToPNG();
builder = builder.WithUpdatedPngCoverImage(pngData);
}
SavedGameMetadataUpdate updatedMetadata = builder.Build();
savedGameClient.CommitUpdate(game, updatedMetadata, savedData, OnSavedGameWritten);
}
public void OnSavedGameWritten (SavedGameRequestStatus status, ISavedGameMetadata game) {
if (status == SavedGameRequestStatus.Success) {
// handle reading or writing of saved game.
} else {
// handle error
}
}
public Texture2D getScreenshot() {
// Create a 2D texture that is 1024x700 pixels from which the PNG will be
// extracted
Texture2D screenShot = new Texture2D(1024, 700);
// Takes the screenshot from top left hand corner of screen and maps to top
// left hand corner of screenShot texture
screenShot.ReadPixels(
new Rect(0, 0, Screen.width, (Screen.width/1024)*700), 0, 0);
return screenShot;
}
讀取遊戲進度存檔
開啟遊戲進度存檔的檔案後,即可藉由讀取此檔案載入遊戲狀態。做法是呼叫 ReadBinaryData。
void LoadGameData (ISavedGameMetadata game) {
ISavedGameClient savedGameClient = PlayGamesPlatform.Instance.SavedGame;
savedGameClient.ReadBinaryData(game, OnSavedGameDataRead);
}
public void OnSavedGameDataRead (SavedGameRequestStatus status, byte[] data) {
if (status == SavedGameRequestStatus.Success) {
// handle processing the byte array data
} else {
// handle error
}
}
刪除遊戲進度存檔
開啟遊戲進度存檔的檔案後,即可刪除這個檔案。做法是呼叫 Delete。
void DeleteGameData (string filename) {
// Open the file to get the metadata.
ISavedGameClient savedGameClient = PlayGamesPlatform.Instance.SavedGame;
savedGameClient.OpenWithAutomaticConflictResolution(filename, DataSource.ReadCacheOrNetwork,
ConflictResolutionStrategy.UseLongestPlaytime, DeleteSavedGame);
}
public void DeleteSavedGame(SavedGameRequestStatus status, ISavedGameMetadata game) {
if (status == SavedGameRequestStatus.Success) {
ISavedGameClient savedGameClient = PlayGamesPlatform.Instance.SavedGame;
savedGameClient.Delete(game);
} else {
// handle error
}
}