目標C內存泄漏問題

Question

我在下面的目標C代碼中有內存泄漏問題。標有的粗體星號（***）行是存在內存泄漏的行（在儀器中提到）。任何想法？謝謝。

- (UIImage*)part:(float)part ofImage:(UIImage*)imgObject withMask:(UIImage*)imgMask { 
UIImage *imgResult = nil; 
CGRect rcMask = CGRectMake(0.0f, 0.0f, imgMask.size.width, imgMask.size.height); 
CGRect rcObject = CGRectMake(0.5f * (rcMask.size.width - imgObject.size.width), 0.0f, imgObject.size.width, imgObject.size.height * part); 

BytePtr pictureData = (BytePtr)malloc(rcMask.size.width * rcMask.size.height * 4); 
CGContextRef pictureContext = CGBitmapContextCreate(pictureData, rcMask.size.width,    rcMask.size.height,8, rcMask.size.width * 4,CGImageGetColorSpace(imgObject.CGImage),    kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); 

CGContextClipToMask(pictureContext, rcMask, imgMask.CGImage); 
CGImageRef imgInRect; 
imgInRect = CGImageCreateWithImageInRect(imgObject.CGImage, rcObject); 
CGContextDrawImage(pictureContext, rcObject, imgInRect); 
CGImageRelease(imgInRect); 
***imgResult = [UIImage imageWithCGImage:CGBitmapContextCreateImage(pictureContext)];*** 

CGContextRelease(pictureContext); 
free(pictureData); 
return imgResult; 
} 

Answer 1

imgResult = [UIImage imageWithCGImage:CGBitmapContextCreateImage(pictureContext)]; 

您創建一個CGImage，它傳遞給UIImage工廠方法，然後忘掉它。你在泄漏CGImage。

而是執行此操作：

CGImageRef cgResult = CGBitmapContextCreateImage(pictureContext); 
if (cgResult) { 
    imgResult = [UIImage imageWithCGImage: cgResult]; 
    CGImageRelease(cgResult); 
}