//获取路径
 NSString *path = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
 // 计算文件夹所有问价所占的空间
 CGFloat size = [self caculateFileCapacityAtPath:path];
 // 移除所有的缓存
 [self removeFileAtPath:path];

计算文件夹大小

-(CGFloat)caculateFileCapacityAtPath:(NSString *)path{
    //获取所有文件的大小
    CGFloat totalsize = 0.0 ;
    NSFileManager *filemanage = [NSFileManager defaultManager];
    if ([filemanage fileExistsAtPath:path]) {
        NSArray *subpaths = [filemanage subpathsAtPath:path];
        NSEnumerator *enuerr = [subpaths objectEnumerator];
        NSString *subfilepath ;
        while (subfilepath = [enuerr nextObject]) {
            NSString *filepath = [path stringByAppendingPathComponent:subfilepath];
            NSDictionary *dic = [filemanage attributesOfItemAtPath:filepath error:nil];
            if (dic) {
                CGFloat filesize = [[dic objectForKey:@"NSFileSize"] floatValue];
                totalsize += filesize ;
            }else{
                NSLog(@"属性不存在");
            }
        }
        // 返回单位为 M
        return totalsize/(1024.0 * 1024.0) ;
    }else{
        return 0.0 ;
    }
}

清除文件夹下的内容

/* 清除该路径下所有的文件以及文件夹 */
-(void)removeFileAtPath:(NSString *)path{
    NSFileManager *filemanage = [NSFileManager defaultManager];
    if ([filemanage fileExistsAtPath:path]) {
        // 找出该文件夹下所有文件所在的子路径
        NSArray *subpaths = [filemanage subpathsAtPath:path];
        /* NSEnumerator 用于快速遍历subpaths中的元素  */
        NSEnumerator *enumerr = [subpaths objectEnumerator];
        /* 遍历至最后一个对象之后 返回值为空 */
        NSString *subpath ;
        while (subpath = [enumerr nextObject]) {
            NSString *filepath = [path stringByAppendingPathComponent:subpath];
            [filemanage removeItemAtPath:filepath error:nil];
        }
    }else{
        NSLog(@"该文件夹不存在");
    }
}