ios 缓存

- (void)clearFile
{
    NSString * cachePath = [NSSearchPathForDirectoriesInDomains (NSCachesDirectory , NSUserDomainMask , YES ) firstObject];
    NSArray * files = [[NSFileManager defaultManager ] subpathsAtPath :cachePath];
    NSLog ( @"cachpath = %@" , cachePath);
    for ( NSString * p in files) {
        NSLog ( @"cachpath = %@" , files);
        NSError * error = nil ;
        //获取文件全路径
        NSString * fileAbsolutePath = [cachePath stringByAppendingPathComponent :p];

        if ([[NSFileManager defaultManager ] fileExistsAtPath :fileAbsolutePath]) {
            [[NSFileManager defaultManager ] removeItemAtPath :fileAbsolutePath error :&error];
        }
    }
    //读取缓存大小
    float cacheSize = [self readCacheSize] *1024;
    NSLog(@"%@",[NSString stringWithFormat:@"%.2fKB",cacheSize]);
    //NSLog();
}
-( float )readCacheSize
{
    NSString *cachePath = [NSSearchPathForDirectoriesInDomains (NSCachesDirectory , NSUserDomainMask , YES) firstObject];

    return [ self folderSizeAtPath :cachePath];
}
//由于缓存文件存在沙箱中，我们可以通过NSFileManager API来实现对缓存文件大小的计算。
// 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 ){
        //获取文件全路径
        NSString * fileAbsolutePath = [folderPath stringByAppendingPathComponent :fileName];
        folderSize += [ self fileSizeAtPath :fileAbsolutePath];
    }
    NSLog(@"%f",folderSize/( 1024.0 * 1024.0));
    return folderSize/( 1024.0 * 1024.0);
}
// 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;
}

iOS中显示获取缓存的大小多少M，点击清除缓存方法 (2016-03-03 12:12:01)
// 显示缓存大小
-( float )filePath
{

    NSString * cachPath = [ NSSearchPathForDirectoriesInDomains ( NSCachesDirectory , NSUserDomainMask , YES ) firstObject ];

    return [ self folderSizeAtPath :cachPath];

}
//1:首先我们计算一下 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 ;

}
//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 );

}




// 清理缓存

- (void)clearFile
{
    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 " );

    NSIndexPath *index=[NSIndexPath indexPathForRow:0 inSection:0];//刷新
    [_tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:index,nil] withRowAnimation:UITableViewRowAnimationNone];
 }