iPhone游戏该如何保存

核心提示：//Player.m//init a player or monster from a coder- (id) initWithCoder: (NSCoder *) coder{type = [[coder decodeObjectForKey:@"type" ] intValue]; //load

//Player.m

//init a player or monster from a coder

- (id) initWithCoder: (NSCoder *) coder

{

type = [[coder decodeObjectForKey:@"type" ] intValue]; //load type number

//init based on type number

[self initWithType: type];

// load x and y position

position.x = [[coder decodeObjectForKey:@"position.x" ] floatValue];

position.y = [[coder decodeObjectForKey:@"position.y" ] floatValue];

health = [[coder decodeObjectForKey:@"health" ] intValue];

return self;

}

The only trick here is that I find out what type of player I’m dealing with first, and then init the correct type. Other than that both snippets follow the same pattern ? init the object with the regular initializer (the same one I would use when starting a new game) and then apply the information from the saved game.

The final part you can’t see is the game information that I discard entirely ? like any particles or damage decals on the screen, or currently playing sound effects. These are all short-term effects that don’t affect the gameplay, and the player won’t miss them when the game reloads. Any ongoing effects ? like flames that can damage characters or poisonous clouds to be avoided- would have to be saved, though. You have to decide what is just a visual effect, and what is part of the simulation.

Starting the party

In case you’ve forgotten how all these methods get called, we kick it all off with these lines:

//load the map from disk; its array of players gets loaded too.

//This causes “intiWithCoder” to be called

myMap = [NSKeyedUnarchiver unarchiveObjectWithFile: filePath];

//take some action if myMap == nil (will happen if save file does not exist)

//save the map to disk; it contains an array of players, so they get saved