读取App.config自定义标签的值

一：程序截图

二：具体代码

config配置：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="MySection111" type="configToRead.MySection1,configToRead" />
    <section name="MySection444" type="configToRead.MySection4, configToRead" />
  </configSections>
  <MySection111 username="红马車" url="http://www.cnblogs.com/hongmaju/"></MySection111>

  <MySection444>
    <add key="aa" value="11111"></add>
    <add key="bb" value="22222"></add>
    <add key="cc" value="33333"></add>
  </MySection444>
</configuration>

要在程序中使用自定义配置我们还需要实现存取这个配置块的类型，一般需要做如下三件事：
1. 定义类型从System.Configuration.ConfigurationSection继承
2. 定义配置类的属性，这些属性需要用ConfigurationProperty特性修饰，并制定属性在配置节中的名称和其他一些限制信息
3. 通过基类的string索引器实现属性的get ，set

MySection1.cs代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;

namespace configToRead
{
    public class MySection1 : ConfigurationSection
    {
        [ConfigurationProperty("username", IsRequired = true)]
        public string UserName
        {
            get { return this["username"].ToString(); }
            set { this["username"] = value; }
        }

        [ConfigurationProperty("url", IsRequired = true)]
        public string Url
        {
            get { return this["url"].ToString(); }
            set { this["url"] = value; }
        }
    }
}

MySection4.cs代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;

namespace configToRead
{
    public class MySection4 : ConfigurationSection    // 所有配置节点都要选择这个基类
    {
        private static readonly ConfigurationProperty s_property
            = new ConfigurationProperty(string.Empty, typeof(MyKeyValueCollection), null, 
                                            ConfigurationPropertyOptions.IsDefaultCollection);
        
        [ConfigurationProperty("", Options = ConfigurationPropertyOptions.IsDefaultCollection)]
        public MyKeyValueCollection KeyValues
        {
            get
            {
                return (MyKeyValueCollection)base[s_property];
            }
        }
    }


    [ConfigurationCollection(typeof(MyKeyValueSetting))]
    public class MyKeyValueCollection : ConfigurationElementCollection        // 自定义一个集合
    {
        // 基本上，所有的方法都只要简单地调用基类的实现就可以了。

        public MyKeyValueCollection() : base(StringComparer.OrdinalIgnoreCase)    // 忽略大小写
        {
        }

        // 其实关键就是这个索引器。但它也是调用基类的实现，只是做下类型转就行了。
        new public MyKeyValueSetting this[string name]
        {
            get
            {
                return (MyKeyValueSetting)base.BaseGet(name);
            }
        }

        // 下面二个方法中抽象类中必须要实现的。
        protected override ConfigurationElement CreateNewElement()
        {
            return new MyKeyValueSetting();
        }
        protected override object GetElementKey(ConfigurationElement element)
        {
            return ((MyKeyValueSetting)element).Key;
        }

        // 说明：如果不需要在代码中修改集合，可以不实现Add, Clear, Remove
        public void Add(MyKeyValueSetting setting)
        {
            this.BaseAdd(setting);
        }
        public void Clear()
        {
            base.BaseClear();
        }
        public void Remove(string name)
        {
            base.BaseRemove(name);
        }
    }

    public class MyKeyValueSetting : ConfigurationElement    // 集合中的每个元素
    {
        [ConfigurationProperty("key", IsRequired = true)]
        public string Key
        {
            get { return this["key"].ToString(); }
            set { this["key"] = value; }
        }

        [ConfigurationProperty("value", IsRequired = true)]
        public string Value
        {
            get { return this["value"].ToString(); }
            set { this["value"] = value; }
        }
    }
}

前台代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using configToRead;
using System.Configuration;
using System.Net.Configuration;
using System.Collections.Specialized;

namespace configToRead
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            MySection1 mySectioin1 = (MySection1)ConfigurationManager.GetSection("MySection111");
            textBox1.Text = mySectioin1.UserName;
            textBox1.Text += mySectioin1.Url;

            MySection4 mySection4 = (MySection4)ConfigurationManager.GetSection("MySection444");
            txtKeyValues.Text = string.Join("
",
                                    (from kv in mySection4.KeyValues.Cast<MyKeyValueSetting>()
                                     let s = string.Format("{0}={1}", kv.Key, kv.Value)
                                     select s).ToArray());
           
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            MySection4 mySection4 = (MySection4)ConfigurationManager.GetSection("MySection444");
                comboBox1.Items.AddRange((from kv in mySection4.KeyValues.Cast<MyKeyValueSetting>()
                                     let s = string.Format("{0}", kv.Key)
                                     select s).ToArray());//linqToSql
        }
    }
}

三：报错解决

将App.config包含到项目即可