缓存清理

// 显示缓存大小

//NSDocumentDirectory  Document目录中的数据

//NSCachesDirectory     缓存中的数据

- ( float )filePath

{

    //NSDocumentDirectory  Document目录中的数据
    //NSCachesDirectory     缓存中的数据
    NSString * cachPath = [ NSSearchPathForDirectoriesInDomains ( NSCachesDirectory , NSUserDomainMask , YES ) firstObject ];

    UIAlertView * alertView = [[ UIAlertView alloc ] initWithTitle : @" 提示 " message : [NSString stringWithFormat:@"%f",[ self folderSizeAtPath :cachPath]]  delegate : nil cancelButtonTitle : @" 确定 " otherButtonTitles : nil ];

    [alertView show ];

    return [ self folderSizeAtPath :cachPath];

}

//2: 遍历文件夹获得文件夹大小，返回多少 M（提示：你可以在工程界设置（)m）

//2: 遍历文件夹获得文件夹大小，返回多少 M（提示：你可以在工程界设置（)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 );
}

//3:首先我们计算一下 单个文件的大小

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

    NSFileManager * manager = [ NSFileManager defaultManager ];

    if ([manager fileExistsAtPath :filePath]){

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

    }

    return 0 ;

}

// 清理缓存 方法一

- ( void )clearFile

{
    //NSDocumentDirectory  Document目录中的数据
    //NSCachesDirectory     缓存中的数据
    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 " );

    UIAlertView * alertView = [[ UIAlertView alloc ] initWithTitle : @" 提示 " message : @" 缓存清理完毕 " delegate : nil cancelButtonTitle : @" 确定 " otherButtonTitles : nil ];

    [alertView show ];

    //[ _tableView reloadData ];//清理完之后重新导入数据

}

方法二

//清除缓存
- (void)clear
{
    dispatch_async(
                   dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
                   , ^{
                       NSString *cachPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask, YES) objectAtIndex:0];

                       NSArray *files = [[NSFileManager defaultManager] subpathsAtPath:cachPath];
//                       NSLog(@"files :%d",[files count]);
                       for (NSString *p in files) {
                           NSError *error;
                           NSString *path = [cachPath stringByAppendingPathComponent:p];
                           if ([[NSFileManager defaultManager] fileExistsAtPath:path]) {
                               [[NSFileManager defaultManager] removeItemAtPath:path error:&error];
                           }
                       }
                       [self performSelectorOnMainThread:@selector(clearCacheSuccess) withObject:nil waitUntilDone:YES];});

}
-(void)clearCacheSuccess
{
   NSLog(@"清除缓存");
}