iOS UIImage的剪裁、合并实现

来源：互联网发布：mac 之间airdrop怎么用编辑：程序博客网时间：2024/06/03 17:52

原理：1、创建一个输出大小的DC

2、计算图片应该绘制的位置

3、得到DC区域的UIImage

- (UIImage *)imageFromImage:(UIImage *)image inRect:(CGRect)rect

{

CGImageRef sourceImageRef = [image CGImage];

CGImageRef newImageRef = CGImageCreateWithImageInRect(sourceImageRef, rect);

UIImage *newImage = [UIImage imageWithCGImage:newImageRef];

CGImageRelease(newImageRef);

return newImage;

}

//得到原图右边某区域

-(UIImage *)getImageFromImage:(UIImage *)image inRect:(CGRect)rect

{

CGSize sz = [image size];

UIGraphicsBeginImageContextWithOptions(CGSizeMake(rect.size.width, sz.height), NO, 0);

[image drawAtPoint:CGPointMake(-(sz.width - rect.size.width), 0)];

UIImage* im = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return im;

}

//将同等高的2图中部分区域合并到一图

-(UIImage *)combineImage:(UIImage*)image1 rectone:(CGRect)rc1 imageteo:(UIImage*)image2 recttwo:(CGRect)rc2//left

{

UIGraphicsBeginImageContextWithOptions(CGSizeMake(DEFAULT_PIC_WIDTH, DEFAULT_PIC_HEIGHT), NO, 0);

[image1 drawAtPoint:CGPointMake(-(rc1.origin.x), 0)];

[image2 drawAtPoint:CGPointMake(rc1.size.width, 0)];

UIImage* image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndPDFContext();

return image;

}

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