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这是我在 UIImage 上的类别中使用的一种方法来调整它的大小。一切正常,但似乎这种方法(我什至不能 100% 确定它在其中)正在积累内存。我不是专家,我已经很难使用 Instruments.app 将其追溯到 CGContext 函数

http://bytolution.com/instruments_scrnsht.png

- (UIImage *)cropWithSquareRatioAndResolution:(CGFloat)resolution
{
    UIImage *sourceImg = (UIImage*)self;
    CGSize size = [sourceImg size];
    int padding = 0;
    int pictureSize;
    int startCroppingPosition;
    if (size.height > size.width) {
        pictureSize = size.width - (2.0 * padding);
        startCroppingPosition = (size.height - pictureSize) / 2.0;
    } else {
        pictureSize = size.height - (2.0 * padding);
        startCroppingPosition = (size.width - pictureSize) / 2.0;
    }
    if (resolution == 0) resolution = sourceImg.size.width;
    CGRect cropRect = CGRectMake(startCroppingPosition, padding, pictureSize, pictureSize);    
    CGRect newRect = CGRectIntegral(CGRectMake(0, 0,resolution, resolution));
    CGImageRef imageRef = CGImageCreateWithImageInRect([sourceImg CGImage], cropRect);

    // Build a context that's the same dimensions as the new size
    CGContextRef bitmap = CGBitmapContextCreate(NULL,
                                            newRect.size.width,
                                            newRect.size.height,
                                            CGImageGetBitsPerComponent(imageRef),
                                            0,
                                            CGImageGetColorSpace(imageRef),
                                            CGImageGetBitmapInfo(imageRef));

    CGContextSetInterpolationQuality(bitmap, kCGInterpolationHigh);
    CGContextDrawImage(bitmap, newRect, imageRef);
    CGImageRef newImageRef = CGBitmapContextCreateImage(bitmap);
    UIImage *newImage = [UIImage imageWithCGImage:newImageRef scale:1.0 orientation:self.imageOrientation];

    // Clean up
    CGContextRelease(bitmap);
    CGImageRelease(newImageRef);
    CGImageRelease(imageRef);

    return newImage;
}

在上面的屏幕截图中,您可以看到拍摄每张图像(并由该方法处理)时内存使用量如何增加。顺便说一句,我正在使用 SDK 7 和 ARC。

我怎样才能摆脱这种泄漏或其他什么?需要释放什么(或者我在代码中遗漏了什么)?

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