Cocos2D：通过CCCallFuncND传递CGPoint [英] Cocos2D: Passing a CGPoint through CCCallFuncND

问题描述

使用动作调用方法的适当方法是什么，以及传递CGPoint参数时该方法本身应该是什么样子？我已经尝试在网上查找例子，没有太多的运气，所以我一直在猜猜。

What is the appropriate way to call a method with an action, and what should the method itself look like for passing a CGPoint parameter? I've tried to look up examples online without much luck, so I've been pretty much guessing.

我试过的是这样调用它：

What I have tried is this for calling it:

    CGPoint spriteCoord = saveStation.sprite.position;

    id a1=[CCMoveTo actionWithDuration:.4 position:ccp(saveStation.sprite.position.x,saveStation.sprite.position.y)];
    id actionSaveStationReaction = [CCCallFuncND actionWithTarget:self selector:@selector(saveStationReaction : data:) data:&spriteCoord];

    [hero.heroSprite runAction:[CCSequence actions:a1, actionSaveStationReaction, nil]];

方法本身：

-(void) saveStationReaction:(id)sender data:(void *)data {

    CGPoint spriteCoord = (void *)data; //error: Invalid initializer 

    NSLog(@"spriteCoord x = %f", spriteCoord.x);
    NSLog(@"spriteCoord y = %f", spriteCoord.y);

}

推荐答案

发送一个CGPoint（或任何非id类型像C structs）到一个方法，以一个id作为参数（使用performSelector的任何方法）是通过将它包装在一个NSValue对象：

The proper way to send a CGPoint (or any non-id type like C structs) to a method that takes an id as parameter (any method that uses performSelector) is by wrapping it in an NSValue object:

NSValue* value = [NSValue valueWithBytes:&spriteCoord objCType:@encode(CGPoint)];

在被调用的方法中，可以通过转换数据指针从NSValue对象中检索点到NSValue *并调用getValue：

In the method that is being called you can retrieve the point from the NSValue object by casting the data pointer to NSValue* and calling getValue:

-(void) saveStationReaction:(id)sender data:(void *)data {

    CGPoint spriteCoord;
    [((NSValue*)data) getValue:&spriteCoord];

    NSLog(@"spriteCoord x = %f", spriteCoord.x);
    NSLog(@"spriteCoord y = %f", spriteCoord.y);

}

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