Question

运行以下代码时发生内存泄漏。我甚至没有使用或持有newImage对象。

for image in imageArray {
    autoreleasepool {
        let newImage = image.scalingWith(targetSize: CGSize(width: 500, height: 500))
    }
}

以下是UIImage扩展名中的缩放方法：

func scaleWith(targetSize: CGSize, backgroundColor: UIColor = UIColor
    .white) -> UIImage? {
    let imageSize = size
    var scaleFactor: CGFloat = 0.0
    let scaledWidth = targetSize.width
    let scaledHeight = targetSize.height
    var thumbnailPoint = CGPoint.zero

    if imageSize.equalTo(targetSize) { return self }

    let widthFactor = targetSize.width / imageSize.width
    let heightFactor = targetSize.height / imageSize.height

    if widthFactor > heightFactor {
        scaleFactor = heightFactor
        thumbnailPoint.x = (targetSize.width - scaleFactor * imageSize.width) * 0.5;
    } else {
        scaleFactor = widthFactor
        thumbnailPoint.y = (targetSize.height - scaleFactor * imageSize.height) * 0.5;
    }

    UIGraphicsBeginImageContext(CGSize(width: scaledWidth, height: scaledHeight))

    let context = UIGraphicsGetCurrentContext()
    let bounds = CGRect(x: 0, y: 0, width: scaledWidth, height: scaledHeight)
    context!.setFillColor(backgroundColor.cgColor)
    context!.fill(bounds)

    var thumbnailRect = CGRect.zero
    thumbnailRect.size.width = imageSize.width * scaleFactor;
    thumbnailRect.size.height = imageSize.height * scaleFactor;
    thumbnailRect.origin = thumbnailPoint

    draw(in: thumbnailRect)
    let resultImage = UIGraphicsGetImageFromCurrentImageContext()

    UIGraphicsEndImageContext();

    return resultImage
}

有人能给我一些建议吗？

Answer 1

通常，在启用了内存泄漏的仪器中运行此代码相当容易。此外，您需要在设备上运行它，因为在模拟器上运行它会产生错误的结果。 Xcode中存在一个错误，即在调试模式和使用控制台时它没有释放对象。

再次：在设备上运行仪器。代码看起来不错，应该没有内存泄漏。考虑到该循环中的代码，还需要autoreleasepool吗？

iOS：尝试扩展UIImage时内存泄漏

1 个答案: