释放 CGMutablePathRef 是有问题的答案

【问题标题】：Releasing CGMutablePathRef is problematic释放 CGMutablePathRef 是有问题的
【发布时间】：2012-05-25 11:19:40
【问题描述】：

我得到hexTouchAreas 作为我的方法-drawHexagonTouchArea 的返回值，但是当我分析我的项目时，它显示CGMutablePathRef hexTouchArea = CGPathCreateMutable(); 的行会产生警告：“在初始化期间存储到'hexTouchArea' 的值永远不会读”。在写有CGPathRelease(hexTouchArea); 的行中，它抱怨我不拥有那个对象，并且释放它是多余的。

另一个警告在 return path; 行，分析器说：“在第 629 行分配并存储到路径中的对象的潜在泄漏（即CGMutablePathRef path = CGPathCreateMutable();）”

-(void)createTouchAreas{

    int realPositionsCount =[[GameStateSingleton sharedMySingleton]getSharedRealCountOfPositions]; 
    hexTouchAreas = [[GameStateSingleton sharedMySingleton]getSharedHexTouchAreas];
    NSMutableDictionary *existingHexagons = [[GameStateSingleton sharedMySingleton]getExistingHexagons];
    for (int i = 0; i <= realPositionsCount;i++){
        //create touchareas
        NSString *hexKey = [NSString stringWithFormat:@"hexagon%d", i];
        CCSprite *theSprite = [[existingHexagons objectForKey:hexKey]objectForKey:@"realSprite"];
        CGPoint touchAreaOrigin = ccp(theSprite.position.x -22, theSprite.position.y-40);
        NSString *touchAreaKey = [NSString stringWithFormat:@"hexTouchArea%d",i];
        CGMutablePathRef hexTouchArea = CGPathCreateMutable();
        hexTouchArea = (CGMutablePathRef) [self drawHexagonTouchArea:touchAreaOrigin];
        [hexTouchAreas setObject:(id)hexTouchArea forKey:touchAreaKey];
        [[GameStateSingleton sharedMySingleton]setSharedHexTouchAreas:hexTouchAreas];
        CGPathRelease(hexTouchArea);

    }



}

创建和返回路径的方法：

-(CGMutablePathRef)drawHexagonTouchArea:(CGPoint)origin
{   


    CGMutablePathRef path = CGPathCreateMutable();
    CGPoint newloc = CGPointMake(origin.x, origin.y);

    CGPathMoveToPoint(path, NULL, newloc.x, newloc.y);
    CGPathAddLineToPoint(path, NULL, newloc.x -22,newloc.y + 38);
    CGPathAddLineToPoint(path, NULL, newloc.x + 0, newloc.y + 76);
    CGPathAddLineToPoint(path, NULL, newloc.x + 46,  newloc.y + 76);
    CGPathAddLineToPoint(path, NULL, newloc.x +66,newloc.y + 40);
    CGPathAddLineToPoint(path, NULL, newloc.x +44, newloc.y + 0);
    CGPathCloseSubpath(path);
    return path;
}

【问题讨论】：

标签： objective-c ipad release memory-leaks cgpath

【解决方案1】：

使用以下代码，您可以创建一个可变路径，将其分配给 hexTouchArea，然后用另一个创建的对象覆盖 hexTouchArea。

CGMutablePathRef hexTouchArea = CGPathCreateMutable();
hexTouchArea = (CGMutablePathRef) [self drawHexagonTouchArea:touchAreaOrigin];

您可能想要使用以下内容。

CGMutablePathRef hexTouchArea = [self drawHexagonTouchArea:touchAreaOrigin];

【讨论】：