iphone - CGMutablePathRef 中的巨大内存泄漏

Question

我在 map 上渲染了近 1000 个多边形。我使用获取多边形的路径

-   (CGPathRef)polyPath:(MKPolygon *)polygon
{
     MKMapPoint *points = [polygon points];
     NSUInteger pointCount = [polygon pointCount];
     NSUInteger i;
     if (pointCount < 3)
         return NULL;
     CGMutablePathRef path = CGPathCreateMutable();
     if([polygon isKindOfClass:[MKPolygon class]])
     {
            for (MKPolygon *interiorPolygon in polygon.interiorPolygons)
      {
       CGPathRef interiorPath = [self polyPath:interiorPolygon];
       CGPathAddPath(path, NULL, interiorPath);
       CGPathRelease(interiorPath);
       }
  }
     CGPoint relativePoint = [self pointForMapPoint:points[0]];
     CGPathMoveToPoint(path, NULL, relativePoint.x, relativePoint.y);
     for (i = 1; i < pointCount; i++) 
     {
            relativePoint = [self pointForMapPoint:points[i]];
            CGPathAddLineToPoint(path, NULL, relativePoint.x, relativePoint.y);
     }
     return path;
}

- (void)drawMapRect:(MKMapRect)mapRect
      zoomScale:(MKZoomScale)zoomScale
      inContext:(CGContextRef)context
{
    MultiPolygon *multiPolygon = (MultiPolygon *)self.overlay;
for (MKPolygon *polygon in multiPolygon.polygons) 
{
    if([polygon isKindOfClass:[MKPolygon class]])
    {
            CGPathRef path = [self polyPath:polygon];
            if (path) 
            {
                [self applyFillPropertiesToContext:context atZoomScale:zoomScale];
                CGContextBeginPath(context);
                CGContextAddPath(context, path);
                CGContextDrawPath(context, kCGPathEOFill);
                [self applyStrokePropertiesToContext:context atZoomScale:zoomScale];
                CGContextBeginPath(context);
                CGContextAddPath(context, path);
                CGContextSetAlpha(context,1.0);
                CGContextStrokePath(context);
            }
            CGPathRelease(path);
    }
}
}

我发现泄漏

CGPathRelease(interiorPath);

和

return path;

我知道我必须使用 CGPathRelease 释放路径，但是当我必须返回时在哪里释放它。

两者都会泄漏大量内存。我已经为此工作好几天了，请帮忙。

提前致谢

Answer 1

您应该将您的方法重命名为 -createPolyPath: 以明确它正在返回一个需要释放的 Core Foundation 对象，然后在您调用 - 的代码中createPolyPath:，你需要像这样释放它:

CGPathRef path = [someObjectOrClass createPolyPath:somePolygon];
// Do some stuff with the path
CGPathRelease(path);

请参阅"Memory Management Programming Guide for Core Foundation" :