web.config配置文件使用总结

我们在开发web系统的时候，使用web.config进行配置是司空见惯的，那么web.confg到底是什么呢？什么时候使用web.config呢？有几种使用web.config方式呢？ 如果不太明白的话，那这篇文章就带领大家脑补下。

》》首先回答第一个问题，web.config是什么？

是一个XML文本文件。用来存储ASP.NETWEB的配置信息。修改不需要重启服务器就可以生效。

》》 然后第二个问题，什么时候使用web.config?

网站中很多不确定的可能随时更改的数据都可以写到配置文件里面。

》》有几种使用web.config的方式呢？

下面就介绍几种常见的：

~ connectionStrings配置（这个一般用来配置数据库连接）

  <connectionStrings>
    <add name="Default" connectionString="Server=.; Database=Inferno;User ID=sa; Password=pwd123;MultipleActiveResultSets=true" providerName="System.Data.SqlClient" />
  </connectionStrings>

获取：

  string dbStr=ConfigurationManager.ConnectionStrings["Default"].ConnectionString;

~appSettings配置（这个一般用来配置不确定的或者需要用户配置的内容）

 <appSettings>
    <add key="webpages:Version" value="3.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>

获取

string clientValidationEnabled= ConfigurationManager.AppSettings["ClientValidationEnabled"].ToString();

~自定义配置（这个一般用户批量配置某些内容）

例如，我下面定义了一个jieDian 键值对配置和一个 fileupload 上传文件集合配置

其中，上面的UploadConditionHandler我对应的是一个类：（这个类需要继承IConfigurationSectionHandler并实现Create方法）

namespace TestProject
{
    public class UploadConditionHandler : IConfigurationSectionHandler
    {
        public UploadConditionHandler() { }
        public static NameValueCollection ossrules = ConfigurationManager.GetSection("testSectionGroup/jieDian") as NameValueCollection;

        public static Dictionary<string, UploadRequiredParameters> ScreensDictionary = ConfigurationManager.GetSection("testSectionGroup/fileupload") as Dictionary<string, UploadRequiredParameters>;
        public object Create(object parent, object configContext, XmlNode section)
        {
            Dictionary<string, UploadRequiredParameters> screens = new Dictionary<string, UploadRequiredParameters>();

            try
            {
                string name = string.Empty;
                string path_rule = string.Empty;
                string disk = string.Empty;
                string receive_server = string.Empty;
                string ext_array = string.Empty;
                string max_memory_size = string.Empty;
                string enum_bucket_name = string.Empty;
                string max_pixel_height = string.Empty;
                string max_pixel_width = string.Empty;
                foreach (XmlNode childNode in section.ChildNodes)
                {
                    if (childNode.NodeType != XmlNodeType.Element || childNode.Name != "upload")
                        continue;

                    if (childNode.Attributes["name"] != null)
                    {
                        name = childNode.Attributes["name"].Value;
                        if (childNode.Attributes["path_rule"] != null)
                        {
                            path_rule = childNode.Attributes["path_rule"].Value;
                        }
                        if (childNode.Attributes["disk"] != null)
                        {
                            disk = childNode.Attributes["disk"].Value;
                        }
                        if (childNode.Attributes["receive_server"] != null)
                        {
                            receive_server = childNode.Attributes["receive_server"].Value;
                        }
                        if (childNode.Attributes["ext_array"] != null)
                        {
                            ext_array = childNode.Attributes["ext_array"].Value;
                        }
                        if (childNode.Attributes["max_memory_size"] != null)
                        {
                            max_memory_size = childNode.Attributes["max_memory_size"].Value;
                        }
                        if (childNode.Attributes["enum_bucket_name"] != null)
                        {
                            enum_bucket_name = childNode.Attributes["enum_bucket_name"].Value;
                        }
                        if (childNode.Attributes["max_height"] != null)
                        {
                            max_pixel_height = childNode.Attributes["max_height"].Value;
                        }
                        if (childNode.Attributes["max_width"] != null)
                        {
                            max_pixel_width = childNode.Attributes["max_width"].Value;
                        }
                        UploadRequiredParameters upload = new UploadRequiredParameters();

                        upload.PathRule = path_rule;
                        upload.Disk = disk;
                        upload.ReceiveServer = receive_server;
                        upload.ExtArray = ext_array;

                        int maxMemorySize = ;
                        if (int.TryParse(max_memory_size, out maxMemorySize))
                        {
                            upload.MaxMemorySize = maxMemorySize;
                        }
                        upload.EnumBucketName = enum_bucket_name;
                        int maxPixelHeight = ;
                        if (int.TryParse(max_pixel_height, out maxPixelHeight))
                        {
                            upload.MaxPixelHeight = maxPixelHeight;
                        }
                        int maxPixelWidth = ;
                        if (int.TryParse(max_pixel_width, out maxPixelWidth))
                        {
                            upload.MaxPixelWidth = maxPixelWidth;
                        }

                        screens.Add(name, upload);
                    }
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
            return screens;
        }
    }
}

好了，上面的步骤完成后，就可以在其它地方调用了：

string jieDian1=UploadConditionHandler.ossrules["JieDian1"];
UploadRequiredParameters res = UploadConditionHandler.ScreensDictionary["UploadRules_Mostly"];

目前就先介绍这么多啦，有什么疑问的或者需要了解的欢迎留言~