清除缓存机制

app中基本上都要有清除缓存功能，下面是自己写的一个清除缓存的事例，有需要的可以看下。大神勿喷，谢谢！
效果图如下

屏幕快照 2016-07-20 21.08.51.png

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"TableCell"];
if (cell == nil)
{
    cell =[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:@"TableCell"];
    cell.selectionStyle = UITableViewCellSelectionStyleNone;
    cell.detailTextLabel.font=[UIFont systemFontOfSize:14];  
}
if (indexPath.row==0) {
    cell.textLabel.text = @"清理缓存";
    cell.detailTextLabel.text=[NSString stringWithFormat:@"%.2fM",[self filePath]];
}else{
    cell.imageView.image = [UIImage imageNamed:@"206040274942060663"];
}
return cell;

}

屏幕快照 2016-07-20 21.09.27.png

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
 {
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
if (indexPath.row==0) {
    //清除缓存
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:nil
                                                        message:@"是否清理缓存？"
                                                       delegate:self
                                              cancelButtonTitle:@"取消"
                                              otherButtonTitles:@"确定", nil];
    [alertView show];     
   }  
}

// 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

- ( 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 );

}



-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
   if (buttonIndex == 1 ) {
    [self clearFile];
    
    }
}

// 清理缓存

- (void)clearFile
{
 dispatch_async(                     dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
               , ^{//地址
                   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];//刷新某一行数据
[_tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:index,nil] withRowAnimation:UITableViewRowAnimationNone];
}

代码通道：https://github.com/Gang679/GZBase 记得Star一下，谢谢！