為了簡(jiǎn)便我們的開發(fā)，通常會(huì)建立一個(gè)分類來(lái)處理我們的程序俄删，廢話不多說(shuō)，直接上代碼：

#import <UIKit/UIKit.h>

typedef enum : NSUInteger {
    ImageRotationAngleZero = 0,//逆時(shí)針旋轉(zhuǎn)0°
    ImageRotationAngleM_PI_2 = 90,//逆時(shí)針旋轉(zhuǎn)90°
    ImageRotationAngleM_PI = 180,//逆時(shí)針旋轉(zhuǎn)180°
    ImageRotationAngle3M_PI_2 = 270//逆時(shí)針旋轉(zhuǎn)270°
} ImageRotationAngle;

@interface UIImage (SnipImage)

/**
 縮放并保存圖片到相冊(cè)

 @param imagePath 圖片地址
 */
+ (void)scaleAndSaveImage:(NSString *)imagePath;

/**
 截屏并保存
 */
+ (void)snipAndSaveImage;

@end

#import "UIImage+SnipImage.h"

@implementation UIImage (SnipImage)

//截屏并裁剪保存圖片
+ (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);
}

//根據(jù)圖片地址裁剪并保存圖片
+ (void)scaleAndSaveImage:(NSString *)imagePath{
    UIImage *image = [UIImage imageWithContentsOfFile:imagePath];
    
    UIImage *saveImage = [self scaleImage:image];
    
    UIImageWriteToSavedPhotosAlbum(saveImage,self, nil, nil);
}

//裁剪圖片(此處容易有坑 *所有的尺寸應(yīng)該是分辨率)
+ (UIImage *)scaleImage:(UIImage *)image{
    CGFloat screenPX_width = [UIScreen mainScreen].bounds.size.width*2;
    CGFloat screenPX_height = [UIScreen mainScreen].bounds.size.height*2;
    
    //裁剪區(qū)域根據(jù)需求自己處理
    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;
}

//旋轉(zhuǎn)圖片到指定角度
+ (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