Question

我有两个非常接近的方法，并且想创建一个我可以调用以保持代码DRY的方法

public IEnumerable<HighScoreViewModel> GetNightlyHighScores()
{
    lock (_Key)
    {
        //return GetHighScores(x => x.NightlyHighScore);

        return _allPlayers
            .OrderByDescending(x => x.NightlyHighScore)
            .Take(8)
            .Select(x=> new HighScoreViewModel
            {
                Points = x.NightlyHighScore,
                PointsText = "FG: " + x.NightlyHighScore,
                ImageUrl = x.Facebook.SmallImageUrl,
                DisplayName = x.DisplayName,
            }).ToList();
    }
}

public IEnumerable<HighScoreViewModel> GetBestHighScores()
{
    lock (_Key)
    {
        //return GetHighScores(x => x.BestHighScore);

        return _allPlayers
            .OrderByDescending(x => x.BestHighScore)
            .Take(8)
            .Select(x => new HighScoreViewModel
            {
                Points = x.BestHighScore,
                PointsText = "FG: " + x.BestHighScore,
                ImageUrl = x.Facebook.SmallImageUrl,
                DisplayName = x.DisplayName,
            }).ToList();
    }
}

我接近某事，但无法弄清楚标有“魔法”的位

public IEnumerable<HighScoreViewModel> GetHighScores<TKey>(Func<Player, TKey> highscore)
{
    return _allPlayers
        .OrderByDescending(highscore)
        .Take(8)
        .Select(x => new HighScoreViewModel
        {
            // Magic?
            //Points = x.BestHighScore,
            PointsText = "FG: " + x.BestHighScore,
            //ImageUrl = x.Facebook.SmallImageUrl,
            DisplayName = x.DisplayName,
        }).ToList();
}

Answer 1

由于BestHighScore和NightlyHighScore具有相同的类型，您应该可以：

public IEnumerable<HighScoreViewModel> GetHighScores(Func<Player, double> highscore)
{
    return _allPlayers
        .OrderByDescending(highscore)
        .Take(8)
        .Select(x => new HighScoreViewModel
        {
            // Magic?
            Points = highScore(x),
            PointsText = "FG: " + x.BestHighScore,
            //ImageUrl = x.Facebook.SmallImageUrl,
            DisplayName = x.DisplayName,
        }).ToList();
}

highscore应该返回Points的实际类型。

Answer 2

不是那么神奇，只需使用该函数从玩家那里获取价值：

public IEnumerable<HighScoreViewModel> GetHighScores<TKey>(Func<Player, TKey> highscore)
{
  return _allPlayers
    .OrderByDescending(highscore)
    .Take(8)
    .Select(x => new HighScoreViewModel
    {
        Points = highscore(x),
        PointsText = "FG: " + highscore(x),
        ImageUrl = x.Facebook.SmallImageUrl,
        DisplayName = x.DisplayName,
    }).ToList();
}

致电：

GetHighScores(x => x.NightlyHighScore)

和

GetHighScores(x => x.BestHighScore)

为具有linq方法的两个类似方法创建抽象

2 个答案: