babalae/better-genshin-impact · error · ArgumentException

角色名集合不能为空。

Error message

角色名集合不能为空。

What it means

Thrown by ParseCharacterNames when the collection is enumerable and all elements are valid strings, but the resulting list is empty (names.Count == 0). An empty collection is not a valid input since there are no characters to process.

Source

Thrown at BetterGenshinImpact/GameTask/CharacterDevelopment/CharacterDevelopmentTask.cs:143

        if (characterNames is not IEnumerable enumerable)
        {
            throw new ArgumentException("角色名参数必须是字符串集合或 JS Array。", nameof(characterNames));
        }

        List<string> names = [];
        foreach (var item in enumerable)
        {
            if (item is not string name)
            {
                throw new ArgumentException("角色名集合中的每个元素都必须是字符串。", nameof(characterNames));
            }

            names.Add(NormalizeCharacterName(name));
        }

        if (names.Count == 0)
        {
            throw new ArgumentException("角色名集合不能为空。", nameof(characterNames));
        }

        return names;
    }

    private static string NormalizeCharacterName(string characterName)
    {
        var name = characterName?.Trim() ?? string.Empty;
        if (string.IsNullOrWhiteSpace(name))
        {
            throw new ArgumentException("角色名不能为空。", nameof(characterName));
        }

        return name;
    }

    internal static CharacterDevelopmentCategory ParseCategories(string? categories)
    {

View on GitHub (pinned to a7cb36712d)

Solutions

1. Pass at least one valid character name in the collection.
2. Check the array length before calling GetMultiCharacters.
3. If no characters are needed, don't call the method at all.

Example fix

// before (wrong)
await dev.GetMultiCharacters([]);
// after
await dev.GetMultiCharacters(['钟离']);

// Check collection is non-empty before calling
if (names is ICollection col && col.Count == 0)
{
    throw new ArgumentException("characterNames collection must not be empty.");
}

static bool IsNonEmptyStringCollection(object obj)
{
    if (obj is string || obj is not IEnumerable e) return false;
    return e.Cast<object>().Any(x => x is string);
}

try
{
    await dev.GetMultiCharacters(names);
}
catch (ArgumentException ex) when (ex.Message.Contains("不能为空"))
{
    // Add at least one character name
}

When it happens

Trigger: Called from ParseCharacterNames. The enumerable yields no elements (e.g. empty array, empty list). All type checks pass but names.Count == 0 at the end.

Common situations: JavaScript caller passes an empty array []; C# caller passes an empty List<string>(); the collection was constructed dynamically and ended up empty.

Related errors

• {paramName} 不能为空
• 多角色接口需要字符串集合或 JS Array，单个字符串请使用 GetCharacter。
• 角色名参数必须是字符串集合或 JS Array。
• 角色名集合中的每个元素都必须是字符串。
• 角色名不能为空。

AI-assisted analysis of babalae/better-genshin-impact@a7cb36712d (2026-08-13). Data as JSON: /api/errors/cc805805f37ab3e1. Report an issue: GitHub.