比較各種枚舉列表的成分

Question

我試圖在單擊按鈕時比較兩個枚舉列表的成分，但我想根據匹配結果接收不同的消息。

更准確地說：我手頭有不同的食譜，如果我選擇的食材與其中一種相匹配，我會收到一條特別的消息。 如果我的食材與任何東西都不匹配，我將收到一條標准消息。

這是我嘗試過但無法正常工作的內容：

public void DrinkButton_Click(object sender, RoutedEventArgs e)
{
    foreach (var recipe in RecipeList)
    {
        List<Ingredients> copy = new List<Ingredients>(selectedPotion.MyIngredients);

        if (copy.Count == recipe.Recipe.Count)
        {
            for (int i = copy.Count - 1; i >= 0; i--)
            {
                Ingredients item = selectedPotion.MyIngredients[i];

                if (recipe.Recipe.Contains(item))
                {
                    copy.Remove(item);
                }
                if (copy.Count == 0)
                {
                    recipe.DrinkEffect();
                }
            }
        }
        else
        {
            MessageBox.Show("Doesn't taste like anything!", "Announcement!", MessageBoxButton.OK, MessageBoxImage.Information);
        }
    }
}

Answer 1

您可以使用Linq的All檢查兩個成分表是否包含相同的元素：

public void DrinkButton_Click(object sender, RoutedEventArgs e)
{
    if (selectedPotion == null)
    {
        MessageBox.Show("Please select a potion to drink", "Help Window", MessageBoxButton.OK, MessageBoxImage.Information);
        return;
    }

    foreach (var recipe in RecipeList)
    {
        bool equalIngredients = recipe.Recipe.All(selectedPotion.MyIngredients.Contains) &&
                                    recipe.Recipe.Count == selectedPotion.MyIngredients.Count;

        if (equalIngredients)
        {
            recipe.DrinkEffect();
            return;
        }
    }

    MessageBox.Show("Doesn't taste like anything!", "Announcement!",
                        MessageBoxButton.OK, MessageBoxImage.Information);
}

這將遍歷RecipeList中的所有項目，並檢查該項目的Recipe等於selectedPotion.MyIngredients 。 如果是這樣，它將在當前項目上調用DrinkEffect()方法，否則它將顯示“不喜歡任何東西！”-MessageBox。

幾點評論：

• recipe.Recipe看起來不對，可能需要更精確的命名
• 該代碼當前不檢查selectedPotion是否為null ，我認為有可能發生NullReferenceException

Answer 2

根據答案，他得出了我的最終解決方案：（我仍然收到“ System.NullReferenceException：'對象引用未設置為對象的實例。”錯誤。）

    public void DrinkButton_Click(object sender, RoutedEventArgs e)
    {            
        foreach (var recipe in RecipeList)
        {               
            bool equalIngredients = recipe.Recipe.All(selectedPotion.MyIngredients.Contains) && recipe.Recipe.Count == selectedPotion.MyIngredients.Count;

            if (equalIngredients)
            {
                recipe.DrinkEffect();
                goto NextStep;
            }
        }
        MessageBox.Show("Doesn't taste like anything!", "Announcement!", MessageBoxButton.OK, MessageBoxImage.Information);
        NextStep: return;      
    }  

Answer 3

這是最新的：

    public void DrinkButton_Click(object sender, RoutedEventArgs e)
    {
        if (selectedPotion == null)
        {
            MessageBox.Show("Please select a potion to drink", "Help Window", MessageBoxButton.OK, MessageBoxImage.Information);
            return;
        }
        else
        {
            foreach (var recipe in RecipeList)
            {
                bool equalIngredients = recipe.Recipe.All(selectedPotion.MyIngredients.Contains) && recipe.Recipe.Count == selectedPotion.MyIngredients.Count;

                if (equalIngredients)
                {
                    recipe.DrinkEffect();
                    goto NextStep;
                }
            }
            MessageBox.Show("Doesn't taste like anything!", "Announcement!", MessageBoxButton.OK, MessageBoxImage.Information);
        NextStep: return;
        }
    }