很早以前看过一句话：“XML就象空气”，在企业应用开发中XML是一个重要的数据交换标准。而XSD则可以用来校验XML的数据格式是否正确。

一个典型的XSD文件如下：

1 
       2 
       3 
      
        4     
       
         5         
        
          6             
         
          运单
          7         
         8         
        
          9             
         
          10                 
          
           11                     
           
            12 
            
             13 
             
              14 
              
               15 
               
                运单前缀只有输入3位数字
               16 
              17 
              
               18 
               
                19 
                20 
               21 
              22 
             23 
             
              24 
              
               25 
               
                运单号只能输入8位数字
               26 
              27 
              
               28 
               
                29 
                30 
               31 
              32 
             33 
            34 
           35                 
          36                 
          
           37                     
           
            38 
            
             39 
             
              40 
              
               41 
               
                物流参与者至少要有2个
               42 
              43 
              
               44 
               
                45 
                
                 46 
                 
                  47 
                  
                   物流参考者类型，只能是A/S/C其中之一
                  48 
                 49 
                 
                  50 
                  
                   51 
                   52 
                   53 
                   54 
                  55 
                 56 
                57 
                58 
               59 
              60 
             61 
            62 
           63                 
          64             
         65         
        66     
       67     
       
        68         
        
         69             
         70             
         71             
         72         
        73     
       74 
      

看到这一大段xml，第一反应通常是头晕，幸好这些内容不用纯手动编写，已经有很多现成的工具，比如XmlSpy可以方便的以GUI方式，通过轻点鼠标，拖拖拉拉就能完成XSD的开发。

这是XmlSpy中XSD的可视化设计界面，还能切换不同的视图，比如下面这样:

对于首次接触XmlSpy的朋友，强烈推荐看下安装目录下的Tutorial.pdf，这是一个不错的入门教程，30分钟以前绝对可以快速浏览一遍。

C#中可以方便的使用XSD来验证xml文件的正确性，示例代码如下：

1 using System; 2 using System.Xml; 3  4 namespace XsdValidate 5 { 6     class Program 7     { 8         static void Main(string[] args) 9         {10             string xmlFile = @"C:\Users\jimmy.yang\Desktop\XMLSPY\TEST\sample.xml";11             string xsdFile = @"C:\Users\jimmy.yang\Desktop\XMLSPY\TEST\sample.xsd";12 13             var xsdValidateResult = ValidateXml(xmlFile, xsdFile);14 15             if (xsdValidateResult.Item1)16             {17                 Console.WriteLine("校验通过！");18             }19             else20             {21                 Console.WriteLine("校验失败，原因:\n" + xsdValidateResult.Item2);22             }23             Console.Read();24 25         }26 27         /// 
28         /// 使用xsd验证xml是否正确29         /// 
30         /// xml文件路径31         /// xsd文件路径32         /// 
      33         static Tuple
      
        ValidateXml(string xmlFilePath, string xsdFilePath)34         {35             Tuple
       
         result = new Tuple
        
         (true, "");36             XmlReaderSettings st = new XmlReaderSettings();37             st.ValidationType = ValidationType.Schema;38             st.Schemas.Add(null, xsdFilePath);39 40             //设置验证xml出错时的事件。41             st.ValidationEventHandler += (obj, e) =>42             {43                 result = new Tuple
         
          (false, e.Message);44             };45 46             XmlReader xr = XmlReader.Create(xmlFilePath, st);47             while (xr.Read())48             {49                 if (xr.IsStartElement())50                 {51                     xr.Read();52                 }53             }54             xr.Close();55             return result;56         }57     }58 }
         
        
       
      

注意：如果节点采用pattern，即正则表达式验证，比如

<xs:restriction base="xs:string">

         <xs:pattern value="^\d{8}$"></xs:pattern>

</xs:restriction>

XMLSpy中，该节点必须填写"^12345678$"才能验证通过，而如果用.NET/JAVA写代码验证的话，^、$能自动识别为"匹配字符开头/结尾"

XSD还能方便的生成c#类，有二种方法：

1、XMLSpy里先打开一个XSD文件，然后 DTD/Schema->Generate Program Code，接下来按提示操作即可

注：XMLSpy生成的c#类太过于复杂，我个人觉得有点啰嗦

2、直接使用vs.net自带的xsd命令

vs.net命令行下，输入

xsd "xsd文件所在的路径" /classes /out:"cs文件的输出目录"

即可生成对应的cs类 ，文中最开头的xsd生成的cs类代码如下：

1 //------------------------------------------------------------------------------  2 // 
      
         3 //     This code was generated by a tool.  4 //     Runtime Version:4.0.30319.18331  5 //  6 //     Changes to this file may cause incorrect behavior and will be lost if  7 //     the code is regenerated.  8 // 
        9 //------------------------------------------------------------------------------ 10  11 using System.Xml.Serialization; 12  13 //  14 // This source code was auto-generated by xsd, Version=4.0.30319.1. 15 //  16  17  18 /// 
       19 [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")] 20 [System.SerializableAttribute()] 21 [System.Diagnostics.DebuggerStepThroughAttribute()] 22 [System.ComponentModel.DesignerCategoryAttribute("code")] 23 [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] 24 [System.Xml.Serialization.XmlRootAttribute(Namespace="", IsNullable=false)] 25 public partial class AWB { 26      27     private AWBAWBINFO aWBINFOField; 28      29     private AWBPARTICIPANT[] pARTINFOField; 30      31     /// 
       32     [System.Xml.Serialization.XmlElementAttribute("AWB-INFO")] 33     public AWBAWBINFO AWBINFO { 34         get { 35             return this.aWBINFOField; 36         } 37         set { 38             this.aWBINFOField = value; 39         } 40     } 41      42     /// 
       43     [System.Xml.Serialization.XmlArrayAttribute("PART-INFO")] 44     [System.Xml.Serialization.XmlArrayItemAttribute("PARTICIPANT", IsNullable=false)] 45     public AWBPARTICIPANT[] PARTINFO { 46         get { 47             return this.pARTINFOField; 48         } 49         set { 50             this.pARTINFOField = value; 51         } 52     } 53 } 54  55 /// 
       56 [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")] 57 [System.SerializableAttribute()] 58 [System.Diagnostics.DebuggerStepThroughAttribute()] 59 [System.ComponentModel.DesignerCategoryAttribute("code")] 60 [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)] 61 public partial class AWBAWBINFO { 62      63     private string aWBPREField; 64      65     private string aWBNOField; 66      67     /// 
       68     [System.Xml.Serialization.XmlElementAttribute(DataType="positiveInteger")] 69     public string AWBPRE { 70         get { 71             return this.aWBPREField; 72         } 73         set { 74             this.aWBPREField = value; 75         } 76     } 77      78     /// 
       79     [System.Xml.Serialization.XmlElementAttribute(DataType="positiveInteger")] 80     public string AWBNO { 81         get { 82             return this.aWBNOField; 83         } 84         set { 85             this.aWBNOField = value; 86         } 87     } 88 } 89  90 /// 
       91 [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")] 92 [System.SerializableAttribute()] 93 [System.Diagnostics.DebuggerStepThroughAttribute()] 94 [System.ComponentModel.DesignerCategoryAttribute("code")] 95 public partial class AddressType { 96      97     private string nameField; 98      99     private string streetField;100     101     private string cityField;102     103     /// 
      104     public string Name {105         get {106             return this.nameField;107         }108         set {109             this.nameField = value;110         }111     }112     113     /// 
      114     public string Street {115         get {116             return this.streetField;117         }118         set {119             this.streetField = value;120         }121     }122     123     /// 
      124     public string City {125         get {126             return this.cityField;127         }128         set {129             this.cityField = value;130         }131     }132 }133 134 /// 
      135 [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")]136 [System.SerializableAttribute()]137 [System.Diagnostics.DebuggerStepThroughAttribute()]138 [System.ComponentModel.DesignerCategoryAttribute("code")]139 [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)]140 public partial class AWBPARTICIPANT {141     142     private AWBPARTICIPANTTYPE tYPEField;143     144     private AddressType aDDRESSField;145     146     /// 
      147     public AWBPARTICIPANTTYPE TYPE {148         get {149             return this.tYPEField;150         }151         set {152             this.tYPEField = value;153         }154     }155     156     /// 
      157     public AddressType ADDRESS {158         get {159             return this.aDDRESSField;160         }161         set {162             this.aDDRESSField = value;163         }164     }165 }166 167 /// 
      168 [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")]169 [System.SerializableAttribute()]170 [System.Xml.Serialization.XmlTypeAttribute(AnonymousType=true)]171 public enum AWBPARTICIPANTTYPE {172     173     /// 
      174     C,175     176     /// 
      177     S,178     179     /// 
      180     A,181 }

xsd命令还能直接根据xml生成xsd文件，使用方法如下：

xsd c:\sampe.xml /out:c:\

这样会根据sample.xml在c:\生成sample.xsd文件