iOS 核心基础 - 分析警告

Question

我正在分析我的应用程序并收到以下警告。有人可以帮我解决这个问题吗？所有其他错误都消失了。

这是代码：

- (void)drawInContext:(CGContextRef)context
{
    if (!self.isPresentationLayer) {
        self.contentsScale = [[UIScreen mainScreen] init].scale;
    }

    CGMutablePathRef path = CGPathCreateMutable();
    self.mainPath = (CGMutablePathRef)CGPathCreateCopy(path);

   CGContextSaveGState(context);

    [self customDrawInContext:context];
    [self drawMainPathImageInContext:context];

    CGContextRestoreGState(context);

    CGPathRelease(path);

    self.isAllowedToAnimate = YES;
}

这是警告消息：

1.) 调用函数“CGPathCreateCopy”返回一个保留计数 +1 的 Core Foundation 对象

2.) 对象泄漏：分配的对象在此执行路径中稍后不会被引用，并且保留计数为+1

Answer 1

我认为问题出在这里：

self.contentsScale = [[UIScreen mainScreen] init].scale;

首先，你不需要

init

，因为主屏幕是

UIScreen

类的静态属性。只要写：

self.contentsScale = [UIScreen mainScreen].scale;

接下来，我认为问题与您的属性存储类型有关。

当你写下：

- (void)drawInContext:(CGContextRef)context
{
    if (!self.isPresentationLayer) {
        self.contentsScale = [[UIScreen mainScreen] init].scale;
    }

    CGMutablePathRef path = CGPathCreateMutable();
    // path as +1 retainCount because of 'create'

    self.mainPath = (CGMutablePathRef)CGPathCreateCopy(path);
    // self.mainPath as +1 retainCount because of 'copy'
    // self.mainPath as again +1 retainCount if the property storage type is retain, copy or strong (I think the error is here)

    CGContextSaveGState(context);

    [self customDrawInContext:context];
    [self drawMainPathImageInContext:context];

    CGContextRestoreGState(context);

    CGPathRelease(path);
    // path as -1 retainCount and so is released.

    self.isAllowedToAnimate = YES;
}