c# - 我有两个组合框和xml文件，我想从xml中填充组合框1中的服务器名称，并根据服务器名称填充第二个组合框

Question

XML:

<?xml version="1.0" encoding="utf-8"?>

<servers>
    <server>s2
        <database>db1</database>
        <database>db2</database>    

    </server>

    <server>s3
        <database>db3</database>
        <database>db4</database>    

    </server>

</servers>

I want to get database based on server name & return as a list of string type.

看法 :

This function will take server name as a parameter from first combo box and based on the will filter database and populate second combobox

public List<string> GetDatabases(string serv)
       {          
           var item = from items in xdoc.Descendants("database")
                      where (string)items.Element("server") == serv
                      select items.Elements("database").ToList();                        
           foreach (var items in item)
           {
               lstDBName.Add(items.ToString());
           }               
           return lstDBName;

       }

Answer 1

您发布的XML无效。如果使用XML validator进行测试，则会看到此错误:

Errors in the XML document: 
    1:  1   Content is not allowed in prolog.

您可以通过添加如下属性来轻松修复它:存储服务器名称，如下所示:

<?xml version="1.0" encoding="utf-8"?>
<servers>
    <server name="s2">
        <database>db1</database>
        <database>db2</database>    
    </server>
    <server name="s3">
        <database>db3</database>
        <database>db4</database>    
    </server>
</servers>

您可以像这样修改(并简化一点)您的代码:

public List<string> GetDatabases(string serv)
{
    XDocument xdoc = XDocument.Load("XMLFile1.xml");
    var lstDBName = (from items in xdoc.Descendants("server")
                     where items.Attribute("name").Value == serv
                     from item in items.Elements("database")
                     select item.Value)
                     .ToList();
    return lstDBName;
}

我从一个名为XMLFile1.xml的文件中读取了方法内部的XML，但是可以在读取XML的同时更改该位。

此代码示例将按预期返回两个字符串的列表，其值分别为“db1”和“db2”