Question

解析从参数中取出的字符串的最佳方法是什么？

我目前正在使用以下函数解析XML节点，但希望将其设为通用。

    private void ParseSettings(XmlDocument doc)
    {
        IsFormVisible = (bool) ParseNode(doc, "Settings/IsFormVisible", IsFormVisible);
        UpdaterRunInterval = (int) ParseNode(doc, "Settings/UpdaterRunInterval", UpdaterRunInterval);
        UpdaterLastRunTime = (DateTime) ParseNode(doc, "Settings/UpdaterLastRunTime", UpdaterLastRunTime);
    }

    private object ParseNode(XmlDocument doc, string node, object defaultValue)
    {
        try
        {
            XmlNode xmlNode = doc.SelectSingleNode(node);
            if (xmlNode == null)
                return defaultValue;
            string text = xmlNode.InnerText;
            if (defaultValue is int)
                return int.Parse(text);
            if (defaultValue is bool)
                return bool.Parse(text);
            if (defaultValue is string)
                return text;
            if (defaultValue is DateTime)
                return DateTime.Parse(text);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        return defaultValue;
    }

Answer 1

private T ParseNode<T>(XmlDocument doc, string node, T defaultValue)
{
    try
    {
        XmlNode xmlNode = doc.SelectSingleNode(node);
        if (xmlNode == null)
            return defaultValue;
        string text = xmlNode.InnerText;
        return SafeConvert(text, defaultValue);
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
    return defaultValue;
}

public static T SafeConvert<T>(string s, T defaultValue)
{
    if ( string.IsNullOrEmpty(s) )
        return defaultValue;
    return (T)Convert.ChangeType(s, typeof(T));
}

Answer 2

尝试类似：

private static T ParseNode<T>(XmlDocument doc, string node, object defaultValue)
{
    object ret = defaultValue;
    try
    {

        XmlNode xmlNode = doc.SelectSingleNode(node);
        if (xmlNode == null)
            return default(T);
        string text = xmlNode.InnerText;
        if (defaultValue is int)
            ret = int.Parse(text);
        if (defaultValue is bool)
            ret =  bool.Parse(text);
        if (defaultValue is string)
            ret = text;
        if (defaultValue is DateTime)
            ret = DateTime.Parse(text);

        return (T) ret;
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
    return (T)ret;
}

我无法保证，这是完美的做法，但它有效！

    IsFormVisible = ParseNode<bool>(doc, "Settings/IsFormVisible", true);
    UpdaterRunInterval = ParseNode<int>(doc, "Settings/UpdaterRunInterval", 1);
    UpdaterLastRunTime = ParseNode<DateTime>(doc, "Settings/UpdaterLastRunTime", 1);

用于解析对象的通用函数

2 个答案: