iOS截屏、保存图片到相册

创建一个UIImage分类：

#import <UIKit/UIKit.h>typedef enum : NSUInteger {    ImageRotationAngleZero = 0,//逆时针旋转0°    ImageRotationAngleM_PI_2 = 90,//逆时针旋转90°    ImageRotationAngleM_PI = 180,//逆时针旋转180°    ImageRotationAngle3M_PI_2 = 270//逆时针旋转270°} ImageRotationAngle;@interface UIImage (SnipImage)/** 缩放并保存图片到相册 @param imagePath 图片地址 */+ (void)scaleAndSaveImage:(NSString *)imagePath;/** 截屏并保存 */+ (void)snipAndSaveImage;@end

---

#import "UIImage+SnipImage.h"@implementation UIImage (SnipImage)//截屏并裁剪保存图片+ (void)snipAndSaveImage{    CGSize imageSize = [[UIScreen mainScreen] bounds].size;    UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);    CGContextRef context = UIGraphicsGetCurrentContext();    for (UIWindow *window in [[UIApplication sharedApplication] windows]) {        if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen]) {            CGContextSaveGState(context);            CGContextTranslateCTM(context, [window center].x, [window center].y);            CGContextConcatCTM(context, [window transform]);            CGContextTranslateCTM(context,                                  -[window bounds].size.width * [[window layer] anchorPoint].x,                                  -[window bounds].size.height * [[window layer] anchorPoint].y);            [[window layer] renderInContext:context];            CGContextRestoreGState(context);        }    }    UIImage *snipImage = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    UIImage *saveImage = [self scaleImage:snipImage];    UIImageWriteToSavedPhotosAlbum(saveImage,self, nil, nil);}//根据图片地址裁剪并保存图片+ (void)scaleAndSaveImage:(NSString *)imagePath{    UIImage *image = [UIImage imageWithContentsOfFile:imagePath];    UIImage *saveImage = [self scaleImage:image];    UIImageWriteToSavedPhotosAlbum(saveImage,self, nil, nil);}//裁剪图片(此处容易有坑 *所有的尺寸应该是分辨率)+ (UIImage *)scaleImage:(UIImage *)image{    CGFloat screenPX_width = [UIScreen mainScreen].bounds.size.width*2;    CGFloat screenPX_height = [UIScreen mainScreen].bounds.size.height*2;    CGFloat scaleImage_offset = 10;    CGFloat scaleImage_height = screenPX_height-30*2;    CGFloat scaleImage_width = screenPX_width * 0.635;    CGFloat scaleImage_x = (screenPX_width - scaleImage_width)/2+scaleImage_offset;    CGFloat scaleImage_y = 30;    UIImage *scaleImage = [UIImage imageWithCGImage:CGImageCreateWithImageInRect(image.CGImage, CGRectMake(scaleImage_x, scaleImage_y, scaleImage_width, scaleImage_height))];    UIImage *saveImage = [self rotationImage:scaleImage angle:270];    return saveImage;}//旋转图片到指定角度+ (UIImage *)rotationImage:(UIImage *)image angle:(ImageRotationAngle)angle{    long double rotate = 0.0;    CGRect rect;    float translateX = 0;    float translateY = 0;    float scaleX = 1.0;    float scaleY = 1.0;    switch (angle) {        case ImageRotationAngleZero:            return image;            break;        case ImageRotationAngleM_PI_2:            rotate = M_PI_2;            rect = CGRectMake(0, 0, image.size.height, image.size.width);            translateX = 0;            translateY = -rect.size.width;            scaleY = rect.size.width/rect.size.height;            scaleX = rect.size.height/rect.size.width;            break;        case ImageRotationAngleM_PI:            rotate = M_PI;            rect = CGRectMake(0, 0, image.size.width, image.size.height);            translateX = -rect.size.width;            translateY = -rect.size.height;            break;        case ImageRotationAngle3M_PI_2:            rotate = 3 * M_PI_2;            rect = CGRectMake(0, 0, image.size.height, image.size.width);            translateX = -rect.size.height;            translateY = 0;            scaleY = rect.size.width/rect.size.height;            scaleX = rect.size.height/rect.size.width;            break;        default:            break;    }    UIGraphicsBeginImageContext(rect.size);    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextTranslateCTM(context, 0.0, rect.size.height);    CGContextScaleCTM(context, 1.0, -1.0);    CGContextRotateCTM(context, rotate);    CGContextTranslateCTM(context, translateX, translateY);    CGContextScaleCTM(context, scaleX, scaleY);    CGContextDrawImage(context, CGRectMake(0, 0, rect.size.width, rect.size.height), image.CGImage);    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();    return newImage;}@end