尝试在UIImageView中使用动态创建的UIImage时获取EXC_BAD_ACCESS

Question

I have a code which creating UIImage dynamically from byte buffer and assigning newly created UIImage to UIImageView.image property:

UIImage* UIImageFromDibRect(long w, long h) {
    size_t dataSiz = w * h * 4;
    std::unique_ptr<uint8> data(new uint8[dataSiz]);
    CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, data.get(), dataSiz, NULL);


    // set up for CGImage creation
    size_t bitsPerComponent = 8;
    size_t bitsPerPixel = 32;
    size_t bytesPerRow = 4 * w;
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
    CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
    CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
    CGImageRef imageRef = CGImageCreate(w, h, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);

    // make UIImage from CGImage
    UIImage *uiImage = [UIImage imageWithCGImage:imageRef];
    return uiImage;
}

[...]

@interface ScreenViewController ()
@property (strong, nonatomic) IBOutlet UIImageView *imageView;
@end

[...]

@implementation ScreenViewController

-(void)myMethod {
    UIImage* newImage = UIImageFromDibRect(128, 128);
    self.imageView.image = newImage;
}

@end

So, everything works just perfect in emulator and on my iPhone 6s, but it crashes on my iPad 2 here:

  0x26bd3182 <+138>: ldr    r0, [r2]
  0x26bd3184 <+140>: blx    0x27507218                ; symbol stub for: -[_UIRemoteViewController(_UIRemoteViewController_AutomaticInvaldiation) autorelease]
> 0x26bd3188 <+144>: mov    r0, r5
  0x26bd318a <+146>: blx    0x27507268                ; symbol stub for: __strlcpy_chk$shim
  0x26bd318e <+150>: mov    r0, r4

callstack is empty, ie start->main->UIApplicationMain

I use iOS 9.3.3 for both iPhone 6s and iPad2. Target platform is iOS 9.0

btw. UIImage looks ok after creation. And if i replace my UIImageFromDibRect with something like this:

UIImage* UIImageFromDibRect(long w, long h) {
    CGRect r = CGRectMake(0.0f, 0.0f, w, h);
    UIGraphicsBeginImageContext(r.size);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [[UIColor redColor] CGColor]);
    CGContextFillRect(context, r);

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}

Then everything is working just fine. So, I'm suspicious I'm doing something wrong with CGImageCreate(...) or with CGDataProviderCreateWithData(...)

Any idea?

Thank you!

Answer 1

So first of all, after you created a CGColorSpaceRef and CGImageRef retain count increased and ARC will not release by yourself and it may cause a leak, you need a call CGColorSpaceRelease(colorSpaceRef) and CFRelease(imageRef); and CGDataProviderRelease(provider);

UIImage* UIImageFromDibRect(long w, long h) {
    size_t dataSiz = w * h * 4;
    std::unique_ptr<uint8> data(new uint8[dataSiz]);
    CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, data.get(), dataSiz, NULL);


    // set up for CGImage creation
    size_t bitsPerComponent = 8;
    size_t bitsPerPixel = 32;
    size_t bytesPerRow = 4 * w;
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
    CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
    CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
    CGImageRef imageRef = CGImageCreate(w, h, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);

    // make UIImage from CGImage
    UIImage *uiImage = [UIImage imageWithCGImage:imageRef];

    CFRelease(imageRef);
    CGColorSpaceRelease(colorSpaceRef);
    CGDataProviderRelease(provider);
    return uiImage;
}

and in your second method CGContextRef need release the same CGContextRelease(context);

UIImage* UIImageFromDibRect(long w, long h) {
    CGRect r = CGRectMake(0.0f, 0.0f, w, h);
    UIGraphicsBeginImageContext(r.size);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [[UIColor redColor] CGColor]);
    CGContextFillRect(context, r);

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    CGContextRelease(context);

    return image;
}

Hope this help fix your crash