erpsuiteios/common/UIImage/UIImage+RedAnt.m

//
//  UIImage+RedAnt.m
//  Apex And Drivers
//
//  Created by Jack on 2018/8/29.
//  Copyright © 2018年 USAI. All rights reserved.
//

#import "UIImage+RedAnt.h"
#import <CommonCrypto/CommonCrypto.h>

static dispatch_semaphore_t _lock;

#define Lock() dispatch_semaphore_wait(_lock, DISPATCH_TIME_FOREVER)
#define Unlock() dispatch_semaphore_signal(_lock)

@implementation UIImage (RedAnt)

+ (void)load {
    _lock = dispatch_semaphore_create(1);
}

+ (instancetype)ra_imageWithURL:(NSURL *)url {
    
    if (url == nil) {
        return nil;
    }
    
    if ([url.scheme isEqualToString:@"file"]) {
        return [UIImage imageWithContentsOfFile:url.absoluteString];
    }
    
    NSString *md5 = [self md5:url.absoluteString];
    
    NSString *imgDir = [self imageCacheDir];
    NSString *imgPath = [imgDir stringByAppendingPathComponent:md5];
    
    NSFileManager *fileManager = [NSFileManager defaultManager];
    
    BOOL isDir = NO;
    BOOL exist = [fileManager fileExistsAtPath:imgPath isDirectory:&isDir];
    
    if (exist && !isDir) {
        return [UIImage imageWithContentsOfFile:imgPath];
    } else {
        
        NSData *imgData = [NSData dataWithContentsOfURL:url];
        
        exist = [fileManager fileExistsAtPath:imgDir isDirectory:&isDir];
        if ((exist && isDir) || !exist) {
            [fileManager createDirectoryAtPath:imgDir withIntermediateDirectories:YES attributes:nil error:nil];
        }
        
        UIImage *img = [UIImage imageWithData:imgData];
        if (img) { // 解析图片成功
            Lock();
            if (![fileManager fileExistsAtPath:imgPath]) {
                [imgData writeToFile:imgPath atomically:NO];
            }
            Unlock();
            
            return img;
        } else {
            return nil;
        }
    }
}

+ (NSString *)imageCacheDir {
    return [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"ImageCache"];
}

+ (NSString *)imageCachePath:(NSString *)url {
    
    NSString *md5 = [self md5:url];
    
    NSString *imgDir = [self imageCacheDir];
    NSString *imgPath = [imgDir stringByAppendingPathComponent:md5];
    
    return imgPath;
}

+ (nullable NSString *)md5:(nullable NSString *)str {
    if (!str) return nil;
    
    const char *cStr = str.UTF8String;
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(cStr, (CC_LONG)strlen(cStr), result);
    
    NSMutableString *md5Str = [NSMutableString string];
    for (int i = 0; i < CC_MD5_DIGEST_LENGTH; ++i) {
        [md5Str appendFormat:@"%02x", result[i]];
    }
    return md5Str;
}

+ (UIImage *)img_compress:(UIImage*)image kbsize:(float) size {
    
    
    
    //UIImage *image=[UIImage imageNamed:@"xxoo.jpeg"];
    NSData  *imageData=UIImageJPEGRepresentation(image, 1.f);
    
    if(size>imageData.length/1024)
        return image;
    
    //   CGFloat size=40.f;// kb
    CGFloat scale=size/(imageData.length/1024);
    
    scale = sqrt (scale);
    
    CGSize newsize=image.size;
    newsize.height = newsize.height*scale;
    newsize.width = newsize.width*scale;
    
    return [self scaleImageToSize:image size:newsize];
}

+ (UIImage *)scaleImageToSize:(UIImage *)img size:(CGSize)size {
    // 创建一个bitmap的context
    // 并把它设置成为当前正在使用的context
    UIGraphicsBeginImageContext(size);
    // 绘制改变大小的图片
    [img drawInRect:CGRectMake(0, 0, size.width, size.height)];
    // 从当前context中创建一个改变大小后的图片
    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    // 使当前的context出堆栈
    UIGraphicsEndImageContext();
    // 返回新的改变大小后的图片
    
    //   NSData  *imageData=UIImageJPEGRepresentation(scaledImage, 1.f);
    return scaledImage;
}

@end