清空缓存功能一般在一个项目中都会用到，一般的缓存会保存在Library的Canche目录下（当然，如果是自己写在了别的目录下，就需要另外清空了）

首先获取Library下的Canche缓存的大小,这儿主要是照顾需要显示缓存大小的项目
代码如下:

- (void)GetCanchesSizeWithCompletionBlock:(void(^)(NSInteger totoalsize))completion {
NSURL *diskCacheURL = [NSURL fileURLWithPath:[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] isDirectory:YES];
dispatch_async(dispatch_get_global_queue(0, 0), ^{
    NSUInteger totalSize = 0;
    NSDirectoryEnumerator *fileEnumerator = [[NSFileManager defaultManager] enumeratorAtURL:diskCacheURL
                                               includingPropertiesForKeys:@[NSFileSize]
                                                                  options:NSDirectoryEnumerationSkipsHiddenFiles
                                                             errorHandler:NULL];
    
    for (NSURL *fileURL in fileEnumerator) {
        NSNumber *fileSize;
        [fileURL getResourceValue:&fileSize forKey:NSURLFileSizeKey error:NULL];
        totalSize += [fileSize unsignedIntegerValue];
    }
    if (completion) {
        dispatch_async(dispatch_get_main_queue(), ^{
            completion(totalSize);
        });
    }
});
}

然后清空缓存
代码如下:

- (void)clearCanchesCompletion:(void(^)(void))completion
{
NSString *diskCacheURL = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
dispatch_async(dispatch_get_global_queue(0, 0), ^{
    NSArray *canchefiles = [[NSFileManager defaultManager] subpathsAtPath:diskCacheURL];
    for (NSString *subfile in canchefiles) {// 遍历目录
        NSError *error;
        NSString *path = [diskCacheURL stringByAppendingPathComponent:subfile];
        if ([[NSFileManager defaultManager] fileExistsAtPath:path]) {
            [[NSFileManager defaultManager] removeItemAtPath:path error:&error];
        }
    }
    if (completion) {
        dispatch_async(dispatch_get_main_queue(), ^{
            completion();
        });
    }
});
}

这样就可以清空Canche目录的缓存文件了