iOS中实现imageView任意角度旋转的方法

#import"UIImage+RotateImageTool.h"
#import<QuartzCore/QuartzCore.h>
#import<Accelerate/Accelerate.h>
@implementationUIImage (RotateImageTool)
-(UIImage*)rotateImageWithDegree:(CGFloat)degree{
//将image转化成context
//获取图片像素的宽和高
size_t width =self.size.width*self.scale;
size_t height =self.size.height*self.scale;
//颜色通道为8因为0-255经过了8个颜色通道的变化
//每一行图片的字节数因为我们采用的是ARGB/RGBA所以字节数为width * 4
size_t bytesPerRow =width *4;
//图片的透明度通道
CGImageAlphaInfo info =kCGImageAlphaPremultipliedFirst;
//配置context的参数:
CGContextRef context =CGBitmapContextCreate(nil, width, height,8, bytesPerRow,CGColorSpaceCreateDeviceRGB(),kCGBitmapByteOrderDefault|info);
if(!context) {
return nil;
}
//将图片渲染到图形上下文中
CGContextDrawImage(context,CGRectMake(0,0, width, height),self.CGImage);
uint8_t* data = (uint8_t*)CGBitmapContextGetData(context);
//旋转欠的数据
vImage_Buffer src = { data,height,width,bytesPerRow};
//旋转后的数据
vImage_Buffer dest= { data,height,width,bytesPerRow};
//背景颜色
Pixel_8888 backColor = {0,0,0,0};
//填充颜色
vImage_Flags flags = kvImageBackgroundColorFill;
//旋转context 
vImageRotate_ARGB8888(&src, &dest,nil, degree *M_PI/180.f, backColor, flags);
//将conetxt转换成image
CGImageRef imageRef =CGBitmapContextCreateImage(context);
UIImage* rotateImage =[UIImageimageWithCGImage:imageRefscale:self.scaleorientation:self.imageOrientation];
returnrotateImage;
}

// retina屏幕图片显示问题
[_detailImageView setContentScaleFactor:[[UIScreen mainScreen] scale]];
// 不规则图片显示
_detailImageView.contentMode = UIViewContentModeScaleAspectFill;
_detailImageView.autoresizingMask = UIViewAutoresizingFlexibleHeight;
// 图片大于或小于显示区域
_detailImageView.clipsToBounds = YES;