繁体   English   中英

LINQ查询中的C#不同

[英]C# Distinct in LINQ query

更改一些代码后,我遇到了问题。 我的想法是这样的:我正在计算文档中的单词数,但是每个文档仅包含一个单词的一个副本,例如:

文档1 = Smith Smith Smith Smith Smith => Smith x1

文档2 = Smith Alan Alan => Smith x1,Alan x1

文档3 = John John => John x1

但铁匠的总人数应:

史密斯(Smith)x2(在3个文档中有2个),艾伦(Alan)x1(3个文档中有1个),约翰(x1)(3个文档中有1个)

我认为在我有一个单独的distinct方法之前(它计算所有单词,如果distinct = false ),现在它只产生1

之前的代码:

    private Dictionary<string, int> tempDict = new Dictionary<string, int>();
    private void Splitter(string[] file)
    {              
            tempDict = file
                .SelectMany(i => File.ReadAllLines(i)
                .SelectMany(line => line.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries))                    
                .AsParallel()
                .Select(word => word.ToLower()) 
                .Distinct())
                .GroupBy(word => word)                    
                .ToDictionary(g => g.Key, g => g.Count());
    }

应该对其进行更改,以便它返回字典,但是在制作应用的过程中,将其更改为以下代码:

private Dictionary<string, int> Splitter(string[] file, bool distinct, bool pairs)
{
    var query = file
        .SelectMany(i => File.ReadLines(i)
        .SelectMany(line => line.Split(new[] { ' '}, StringSplitOptions.RemoveEmptyEntries))
        .AsParallel()
        .Select(word => word.ToLower())
        .Where(word => !word.All(char.IsDigit)));
    if (distinct)
    {
        query = query.Distinct();
    }
    if (pairs)
    {
        var pairWise = query.Pairwise((first, second) => string.Format("{0} {1}", first, second));

        return query
                .Concat(pairWise)
                .GroupBy(word => word)
                .ToDictionary(g => g.Key, g => g.Count());
    }
    return query
        .GroupBy(word => word)
        .ToDictionary(g => g.Key, g => g.Count());           
}

还要注意query = file.Distinct(); 仅返回文档名称。 因此,必须有所不同。

@edit这就是我调用此方法的方式:

  private void EnterDocument(object sender, RoutedEventArgs e)
    {
        List<string> myFile= new List<string>();
        OpenFileDialog openFileDialog = new OpenFileDialog();
        openFileDialog.Multiselect = true;
        openFileDialog.Filter = "All files (*.*)|*.*|Text files (*.txt)|*.txt";
        if (openFileDialog.ShowDialog() == true)
        {
            foreach (string filename in openFileDialog.FileNames)
            {
                myFile.Add(filename);

            }
        }
        string[] myFiles= myFile.ToArray();
        myDatabase = Splitter(myFiles, true, false);
    }

Distinct()将从您的IEnumerable删除重复项,因此请在以下操作之前调用它...

return query
    .GroupBy(word => word)
    .ToDictionary(g => g.Key, g => g.Count());  

...将产生所有唯一单词的列表,但计数为1。

编辑:

要解决合并所有行的问题,您可以执行以下操作:

List<string> allFilesWords = new List<string>();
foreach (var filename in file)
{
    var fileQuery = File.ReadLines(filename)
        .SelectMany(line => line.Split(new[] { ' '}, StringSplitOptions.RemoveEmptyEntries))
        .AsParallel()
        .Select(word => word.ToLower())
        .Where(word => !word.All(char.IsDigit)));
    allFilesWords.AddRange(fileQuery.Distinct());
}
return allFilesWords
        .GroupBy(word => word)
        .ToDictionary(g => g.Key, g => g.Count());       

暂无
暂无

声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM