iOS中常见的视图和图片处理示例详解

前言

众所周知在开发中不可避免的会遇到一些图片和视图的处理，我这里总结的这些只是我遇到的一些，以供下次使用查看。下面话不多说了，来一起看看详细的介绍吧。

图片的旋转

是UIImage的扩展类，直接使用UIImage的对象调用即可

UIImage

#import <QuartzCore/QuartzCore.h>
#import <Accelerate/Accelerate.h>
 
@implementation UIImage (ImageRotate)
-(UIImage *)imageRotateIndegree:(float)degree{
 //1.image-》context
 size_t width = (size_t)(self.size.width *self.scale);
 size_t height = (size_t)(self.size.height*self.scale);
 
 size_t bytesPerRow = width * 4;//表明每行图片数据字节
 CGImageAlphaInfo alphaInfo = kCGImageAlphaPremultipliedFirst;//alpha
 //配置上下文参数
 CGContextRef bmContext = CGBitmapContextCreate(NULL, width, height, 8, bytesPerRow, CGColorSpaceCreateDeviceRGB(), kCGBitmapByteOrderDefault | alphaInfo);
 if (!bmContext) {
 return nil;
 }
 CGContextDrawImage(bmContext, CGRectMake(0, 0, width, height), self.CGImage);
 //2旋转
 UInt8 *data = (UInt8*)CGBitmapContextGetData(bmContext);
 vImage_Buffer src = {data,height,width,bytesPerRow};
 vImage_Buffer dest = {data,height,width,bytesPerRow};
 Pixel_8888 bgColor = {0,0,0,0};
 vImageRotate_ARGB8888(&src, &dest, NULL, degree, bgColor, kvImageBackgroundColorFill);
 //3context-》UIImage
 CGImageRef rotateImageref = CGBitmapContextCreateImage(bmContext);
 UIImage *rotateImage = [UIImage imageWithCGImage:rotateImageref scale:self.scale orientation:self.imageOrientation];
 return rotateImage;
}
@end

@implementation UIImage (ImageCut)
 
-(UIImage *)ImageCutSize:(CGRect)rect{
 CGImageRef subImageref = CGImageCreateWithImageInRect(self.CGImage, rect);
 CGRect smallRef = CGRectMake(0, 0, CGImageGetWidth(subImageref), CGImageGetHeight(subImageref));
 
 UIGraphicsBeginImageContext(smallRef.size);
 
 CGContextRef context = UIGraphicsGetCurrentContext();
 CGContextDrawImage(context, smallRef, subImageref);
 UIImage *image = [UIImage imageWithCGImage:subImageref];
 
 UIGraphicsEndImageContext();
 return image;
}
@end

@implementation UIView (imageScreenShot)
- (UIImage *)imageScreenShot
{
 UIGraphicsBeginImageContext(self.frame.size);
 [self.layer renderInContext:UIGraphicsGetCurrentContext()];
 UIImage *imageNew = UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();
 return imageNew;
}
@end

- (void)imageScreen{
 UIImage *imageNew = [self.view imageScreenShot];
 UIImageWriteToSavedPhotosAlbum(imageNew, nil, nil, nil); //直接保存在相册里，要获取相册权限
}