将什么作为字符串参数传递给构造函数？

Question

我有以下情况：

protected MobileWalletRequestBase(XmlDocument xmlDoc, string request)
{
    _xmlDoc = xmlDoc;
}

protected MobileWalletRequestBase()
    : this(new XmlDocument(), ?)
{
    _xmlDoc.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?><request/>");
}

我应该在第二个构造函数中写什么才能传递字符串值？

Answer 1

一种方法是使用默认参数：

protected MobileWalletRequestBase(XmlDocument xmlDoc, string request="foo")
{
    // but you're not using request in here, unclear what's needed
    _xmlDoc = xmlDoc;  
}

protected MobileWalletRequestBase()
    : this(new XmlDocument())   // don't say anything
{
    _xmlDoc.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?><request/>");
}