CGImage到UIImage不工作 [英] CGImage to UIImage doesn't work

问题描述

我正在开发和iOS应用程序为iPad和我使用Grabkit，以便从Facebook，Twitter，Flicker和相机胶卷的图像。要获取最后一个图像，我需要将一个CGImage转换为UIImage，但我遇到了麻烦。就像如果我没有得到任何图像，因为当我后来用的UIImage，应用程序崩溃与此日志：

I'm developing and iOS app for iPad and I use Grabkit in order to get images from Facebook, Twitter, Flicker and also the Camera Roll. To get the images from the last one, I need to convert a CGImage to an UIImage, but I'm having trouble with that. Is like if I didn't get any image, because when I use the UIImage later, the app crashes with this log:

 *** Terminating app due to uncaught exception 'CALayerInvalidGeometry', reason: 'CALayer position contains NaN: [nan 653]'

我用下面的代码的转换CGImage：

I'm using the following code to convert the CGImage:

UIImage* image = [UIImage imageWithCGImage:imgRef];

所以这段代码不会崩溃，但是当我使用创建的映像时，发生什么事？是否错误？

So this code doesn't crash, but when I use the image created, it does. What is happening? Is the code wrong?

推荐答案

您应该使用alloc init like UIImage * myImage = [[UIImage alloc ] initWithCGImage：myCGImage];

You should use alloc init like UIImage* myImage = [[UIImage alloc] initWithCGImage:myCGImage];

或者您可以尝试：

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
NSUInteger width = CGImageGetWidth(image);
NSUInteger height = CGImageGetHeight(image);
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = 8;
int size = height*width*bytesPerPixel;
unsigned char *rawData = malloc(size); 
CGContextRef context = CGBitmapContextCreate(rawData,width,height,bitsPerComponent,bytesPerRow,colorSpace,kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0,0,width,height),image);
UIImage *newImage = [UIImage imageWithCGImage:CGBitmapContextCreateImage(context)];
CGContextRelease(context);    
free(rawData);

这篇关于CGImage到UIImage不工作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！