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#import <Foundation/Foundation.h>#define ImgsDirectory @"Imgs"#define DocumentsPath [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]typedef enum {    SuccessType,    FailedDownloadType,    FailedWriteType,    AlreadyDownloadType,}DownloadType;typedef enum {    SucsessType,    FailedType,    NoFileType,}RemoveType;@interface Download : NSObject+(DownloadType)downloadImageInDirectoryWithUrlString:(NSString *)urlString;+(NSString *)calculateSizeWithDirectoryName:(NSString *)directoryName;+(BOOL)removeAllFileWithDirectoryName:(NSString *)directoryName;+(RemoveType)removeFileWithFileName:(NSString *)fileName inDirectoryName:(NSString *)directoryName;@end

#import "Download.h"@interface Download ()-(NSString *)createDirectoryWithDirectoryName:(NSString *)DirectoryName;-(NSString *)createFileWithFileName:(NSString *)fileName WithDirectoryName:(NSString *)DirectoryName;@end@implementation Download#pragma mark --extension---(NSString *)createDirectoryWithDirectoryName:(NSString *)DirectoryName{    //拼接文件夹路径    NSString *directoryPath = [DocumentsPath stringByAppendingPathComponent:DirectoryName];    NSFileManager *fm = [NSFileManager defaultManager];    if (![fm fileExistsAtPath:directoryPath]) {        [fm createDirectoryAtPath:directoryPath withIntermediateDirectories:YES attributes:nil error:nil];    }    return directoryPath;}-(NSString *)createFileWithFileName:(NSString *)fileName WithDirectoryName:(NSString *)DirectoryName{    NSString *filePath = [DocumentsPath stringByAppendingFormat:@"/%@/%@",DirectoryName,fileName];    return filePath;}+(DownloadType)downloadImageInDirectoryWithUrlString:(NSString *)urlString{    DownloadType type = FailedDownloadType;    //取到 fileName    NSString *fileName = [urlString lastPathComponent];    //拿到文件夹    NSString *imgsDir = [[Download new] createDirectoryWithDirectoryName:ImgsDirectory];    //找到这个文件夹下面的所有文件,查询次文件夹下是否存在当前已经下载的图片    NSArray *fileArrays = [[NSFileManager defaultManager] subpathsAtPath:imgsDir];    for (NSString *element in fileArrays) {        if ([element isEqualToString:fileName]) {            type = AlreadyDownloadType;            break;        }    }    if (type != AlreadyDownloadType) {        urlString = [urlString stringByAddingPercentEscapesUsingEncoding:4];        NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:urlString]];        if (data.length == 0) {            type = FailedDownloadType;        }else{            NSString *filePath = [[Download new] createFileWithFileName:fileName WithDirectoryName:ImgsDirectory];            BOOL flag = [[NSFileManager defaultManager] createFileAtPath:filePath contents:data attributes:nil];            if (flag) {                type = SuccessType;            }else{                type = FailedWriteType;            }        }    }    return type;}+(NSString *)calculateSizeWithDirectoryName:(NSString *)directoryName{    NSString *directoryPath = [DocumentsPath stringByAppendingPathComponent:directoryName];    double count = 0.0;    for (NSString *ele in [[NSFileManager defaultManager] subpathsAtPath:directoryPath]) {        NSString *filePath = [directoryPath stringByAppendingPathComponent:ele];        NSData *data = [NSData dataWithContentsOfFile:filePath];        count += data.length;    }    return [NSString stringWithFormat:@"%.2f M",count/1024/1024];}+(BOOL)removeAllFileWithDirectoryName:(NSString *)directoryName{    NSString *directoryPath = [DocumentsPath stringByAppendingPathComponent:directoryName];    NSFileManager *fm = [NSFileManager defaultManager];    for (NSString *ele in [fm subpathsAtPath:directoryPath]) {        NSString *filePath = [directoryPath stringByAppendingPathComponent:ele];        [fm removeItemAtPath:filePath error:nil];    }    if ([fm subpathsAtPath:directoryPath].count == 0) {        return YES;    }else{        return NO;    }}+(RemoveType)removeFileWithFileName:(NSString *)fileName inDirectoryName:(NSString *)directoryName{    RemoveType type = FailedType;     NSString *directoryPath = [DocumentsPath stringByAppendingPathComponent:directoryName];    NSFileManager *fm = [NSFileManager defaultManager];    BOOL isExist = NO;    for (NSString *ele in [fm subpathsAtPath:directoryPath]) {        if ([ele isEqualToString:fileName]) {            isExist = YES;            NSString *filePath = [directoryPath stringByAppendingPathComponent:ele];            BOOL flag = [fm removeItemAtPath:filePath error:nil];            if (flag) {                type = SucsessType;            }else{                type = FailedType;            }        }    }    if (!isExist) {        type = NoFileType;    }    return type;}@end

#import "ViewController.h"#import "Download.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    NSLog(@"rootPath = %@",NSHomeDirectory());    DownloadType type = [Download downloadImageInDirectoryWithUrlString:@"http://s0.hao123img.com/res/r/image/2015-08-12/e307fb459de2f8acbf9d4f32b85755dc.jpg"];    switch (type) {        case SuccessType:        {            NSLog(@"下载成功");        }            break;        case FailedWriteType:        {            NSLog(@"写入失败");        }            break;        case FailedDownloadType:        {            NSLog(@"无网络");        }            break;        case AlreadyDownloadType:{            NSLog(@"已经下载");        }            break;        default:            break;    }    RemoveType removeType = [Download removeFileWithFileName:@"e307fb459de2f8acbf9d4f32b85755dc.jpg" inDirectoryName:ImgsDirectory];    switch (removeType) {        case NoFileType:        {            NSLog(@"没有此图片");        }            break;        case SucsessType:{            NSLog(@"删除成功");        }            break;        case FailedType:{            NSLog(@"删除失败");        }            break;        default:            break;    }}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end