C#的XML实现记住密码功能

/// <summary>
/// 保存用户
/// </summary>
public void SetUser()
{
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(Application.StartupPath + "//user.xml");
XmlNodeList userNodes = xmlDoc.SelectSingleNode("root").ChildNodes;
foreach (XmlNode userNode in userNodes)
{
XmlNodeList idandpwd = userNode.ChildNodes;
foreach (XmlNode idnode in idandpwd)
{
if (idnode.InnerText == cmbUserName.Text)
{
idnode.NextSibling.InnerText = jnzp.DESEncrypt.Encrypt(txtPwd.Text, "duowanSG");
xmlDoc.Save(Application.StartupPath + "//user.xml");
return;
}
}
}

XmlNode root = xmlDoc.SelectSingleNode("root");//查找<root>
XmlElement user = xmlDoc.CreateElement("user");
XmlElement id = xmlDoc.CreateElement("id");
XmlElement pwd = xmlDoc.CreateElement("pwd");
id.InnerText = cmbUserName.Text;
user.AppendChild(id);
if (checkBox1.Checked)
{
pwd.InnerText = jnzp.DESEncrypt.Encrypt(txtPwd.Text, "duowanSG");
}
else
{
pwd.InnerText = "";
}
user.AppendChild(pwd);
root.AppendChild(user);//添加到<bookstore>节点中
xmlDoc.Save(Application.StartupPath + "//user.xml");

}
/// <summary>
/// 提取密码
/// </summary>
/// <param name="userId">账号</param>
/// <returns></returns>
public string GetPwd(string userId)
{
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(Application.StartupPath + "//user.xml");
XmlNodeList userNodes = xmlDoc.SelectSingleNode("root").ChildNodes;
foreach (XmlNode user in userNodes)
{
XmlNodeList idandpwd = user.ChildNodes;
foreach (XmlNode idnode in idandpwd)
{
if (idnode.InnerText == cmbUserName.Text)
{
string pwd=idnode.NextSibling.InnerText;
if (pwd == "")
{
return "";
}
return jnzp.DESEncrypt.Decrypt(pwd, "duowanSG");
}
}
}
return "";
}

==============================XML格式======================
<?xml version="1.0" encoding="utf-8"?>
<root>
<user>
<id>abcdefg</id>
<pwd>FA52C9C83C4ACD73</pwd>
</user>
</root>

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给你说下思路.
当登录时,记录下账号密码,然后向XML中插入节点(不会的话,自己去网上搜一下),首先需要判断当前XML用户是否有了,有的话修改密码就行,没有新建.
在上面程序中,有checkbox来做判断是否记录密码.