自己写的获取网络图片，不放内存里，包括文件的删除，创建

//

//  UIImageView+CacheURL.m

//  Vodka

//

//  Created by xiaoming on 15/11/5.

//  Copyright © 2015年 Beijing Beast Technology Co.,Ltd. All rights reserved.

//

 

#import "UIImageView+CacheURL.h"

#import "CodeFragments.h"

 

@implementation UIImageView (CacheURL)

 

#pragma mark - 传人urlString 和默认图。获取网络图片。----不放到缓存里面

-(void)setURLString:(NSString *)urlString placeholderImage:(UIImage *)image{

    [selfsetURLString:urlString placeholderImage:image relativePath:nil];

}

 

#pragma mark - 传人urlString 和默认图。获取网络图片。----不放到缓存里面 relativePath 传 nil @"" 跟上面的方法一样，都是 tempCache 路径下。

-(void)setURLString:(NSString *)urlString placeholderImage:(UIImage *)defaultImage relativePath:(NSString *)relativePath{

    if (relativePath == nil || [relativePath isEqualToString:@""]) {

        relativePath = @"tempCache";

    }

    self.image = defaultImage;

    if ([self isEmptyString:urlString]) {

        return;

    }

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        UIImage *resultImage = nil;///从网上获取成功后的image

        //从缓存中读取。

        resultImage = [UIImage imageWithContentsOfFile:[self absolutePath:relativePath urlString:urlString systemPath:nil]];

        if (resultImage) {

            dispatch_async(dispatch_get_main_queue(), ^{

                self.image = resultImage;

            });

            return;

        }

        ///没有缓存的情况下。

        NSURL *url = [NSURL URLWithString:urlString];

        NSData *resultData = [NSData dataWithContentsOfURL:url];

        resultImage = [UIImage imageWithData:resultData];

        if (resultImage) {

            ///缓存data数据。

            NSString *aFileName = [self absolutePath:relativePath urlString:nil systemPath:nil];

            NSFileManager *fileManager = [NSFileManager defaultManager];

            if (![fileManager fileExistsAtPath:aFileName]) {

                ////withIntermediateDirectories  YES 表示可以创建多级目录。

                if (![fileManager createDirectoryAtPath:aFileName withIntermediateDirectories:YESattributes:nilerror:nil]) {

                    NSLog(@"createFile error occurred");

                }

                

            }

            NSString *resultFileString = [self absolutePath:relativePath urlString:urlString systemPath:nil];

            if ([resultData writeToFile:resultFileString atomically:YES]) {

                NSLog(@"保存成功");

            }else{

                NSLog(@"保存失败");

            }

            dispatch_async(dispatch_get_main_queue(), ^{

                self.image = resultImage;

            });

        }

    });

}

 

#pragma mark - 判断是否是空字符串

- (BOOL)isEmptyString:(NSString *)string{

    if(string == nil){

        return YES;

    }

    if([string isKindOfClass:[[NSNull null] class]]){

        return YES;

    }

    if([string isEqualToString:@""]){

        return YES;

    }

    if([string isEqualToString:@"<null>"])

        return YES;

    if([string isEqualToString:@"(null)"])

        return YES;

    returnNO;

}

 

#pragma mark - 从本地文件读取数据。

-(NSString *)absolutePath:(NSString*)relativePath urlString:(NSString *)urlString systemPath:(NSString *)systemPath{

    if (relativePath == nil || [relativePath isEqualToString:@""]) {

        relativePath = @"tempCache";

    }

    NSString *path0 = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0];

    NSString *path1 = [path0 stringByAppendingPathComponent:relativePath];

    if(urlString && ![urlString isEqualToString:@""]){///创建路径的时候不需要url，读，取的时候，需要url。

        NSString *path2 = [path1 stringByAppendingPathComponent:[urlString stringByReplacingOccurrencesOfString:@"/"withString:@"_"]];

        return path2;

    }

    return path1;

}

 

#pragma mark - 清除本地缓存

-(void)cleanDisk{

    NSFileManager *fileManager = [NSFileManagerdefaultManager];

    NSString *path0 = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0];

    NSString *defaultPath = [NSString stringWithFormat:@"%@/tempCache",path0];

    NSLog(@"defaultPaht ==== %@",defaultPath);

    [self folderSizeAtPath:defaultPath];

    if ([fileManager removeItemAtPath:defaultPath error:nil]) {

        NSLog(@"删除成功");

    }else{

        NSLog(@"删除失败");

    }

    

    [self folderSizeAtPath:defaultPath];

}

 

#pragma mark - 通常用于删除缓存的时，计算缓存大小

//单个文件的大小

- (long long) fileSizeAtPath:(NSString*) filePath{

    NSFileManager* manager = [NSFileManagerdefaultManager];

    if ([manager fileExistsAtPath:filePath]){

        return [[manager attributesOfItemAtPath:filePath error:nil] fileSize];

    }

    return 0;

}

#pragma mark - 遍历文件夹获得文件夹大小，返回多少M

- (float ) folderSizeAtPath:(NSString*) folderPath{

    if (!folderPath || [folderPath isEqualToString:@""]) {

        NSString *path0 = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0];

        folderPath = [NSString stringWithFormat:@"%@/tempCache",path0];

    }

    NSFileManager* manager = [NSFileManagerdefaultManager];

    if (![manager fileExistsAtPath:folderPath])

    {

        NSLog(@"大小为0");

        return 0;

    }

    NSEnumerator *childFilesEnumerator = [[manager subpathsAtPath:folderPath] objectEnumerator];

    NSString* fileName;

    long long folderSize = 0;

    while ((fileName = [childFilesEnumerator nextObject]) != nil){

        NSString* fileAbsolutePath = [folderPath stringByAppendingPathComponent:fileName];

        folderSize += [self fileSizeAtPath:fileAbsolutePath];

    }

    NSLog(@"文件大小====%f M ",folderSize/(1024.0*1024.0));

    return folderSize/(1024.0*1024.0);

}

 

@end