iOS开发之如何实现缓存计算及清除缓存

//
// gzhCache.h
// cache
//
// Created by 郭志贺 on 2020/5/27.
// Copyright © 2020 郭志贺. All rights reserved.
//

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface gzhCache : NSObject

/// 计算缓存大小
+(float)filePath;

/// 清理缓存
+(void)clearCache;
@end

NS_ASSUME_NONNULL_END

//
// gzhCache.m
// cache
//
// Created by 郭志贺 on 2020/5/27.
// Copyright © 2020 郭志贺. All rights reserved.
//

#import "gzhCache.h"

@implementation gzhCache
// 显示缓存大小
+ (float)filePath {
  NSString * cachPath = [ NSSearchPathForDirectoriesInDomains ( NSCachesDirectory , NSUserDomainMask , YES ) firstObject ];

  return [ self folderSizeAtPath :cachPath];
}
//计算单个文件的大小
+ (long long) fileSizeAtPath:( NSString *) filePath{
  NSFileManager * manager = [ NSFileManager defaultManager ];
  if ([manager fileExistsAtPath :filePath]){
    return [[manager attributesOfItemAtPath :filePath error : nil ] fileSize ];
  }
  return 0 ;
}
//遍历文件夹获得文件夹大小，返回多少M
+ (float)folderSizeAtPath:(NSString *)folderPath{
  NSFileManager * manager = [ NSFileManager defaultManager ];
  if (![manager fileExistsAtPath :folderPath]) 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];
  }
  return folderSize/( 1024.0 * 1024.0 );
}
//清理缓存
+ (void)clearCache {
  NSString * cachPath = [ NSSearchPathForDirectoriesInDomains ( NSCachesDirectory , NSUserDomainMask , YES ) firstObject ];
  NSArray * files = [[ NSFileManager defaultManager ] subpathsAtPath :cachPath];
  NSLog ( @"cachpath = %@" , cachPath);
  for ( NSString * p in files) {
    NSError * error = nil ;
    NSString * path = [cachPath stringByAppendingPathComponent :p];
    if ([[ NSFileManager defaultManager ] fileExistsAtPath :path]) {
      [[ NSFileManager defaultManager ] removeItemAtPath :path error :&error];
    }
  }
  [ self performSelectorOnMainThread : @selector (clearCachSuccess) withObject : nil waitUntilDone : YES ];
}
+ (void)clearCachSuccess {
  NSLog(@"清理成功");
}
@end

NSString *str = [NSString stringWithFormat:@"%.2fM",[gzhCache filePath]];

[gzhCache clearCache];