Delphi 操作webservice返回值为dataset的处理办法

在微软中国找到了一个官方的说法------不建议将DataSet直接作为返回值传送，因为里面含有大量复杂的schema以及更改等信息，大部分非.NET语言在解析上有困难。建议使用DataSet.WriteXML方法将简化后的XML版本作为一个WideString回传。经过试验，已经在Delphi下轻松通过，Delphi中还需要使用XML Mapper工具事先生成Transfomation(XTR)文件。

Delphi7客户端代码

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unit WSTestMain; 
interface 
uses 
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, 
Dialogs, InvokeRegistry, StdCtrls, Rio, SOAPHTTPClient, Grids, DBGrids, 
DB, DBClient, DBTables, Provider, xmldom, Xmlxform,XMLIntf,XMLDoc,SOAPConst; 
type 
TForm1 = class(TForm) 
HTTPRIO1: THTTPRIO; 
Button1: TButton; 
Memo1: TMemo; 
XMLTransformProvider1: TXMLTransformProvider; 
ClientDataSet1: TClientDataSet; 
DataSource1: TDataSource; 
DBGrid1: TDBGrid; 
procedure Button1Click(Sender: TObject); 
private 
{ Private declarations } 
public 
{ Public declarations } 
end; 
var 
Form1: TForm1; 
implementation 
uses WSTestDefine; 
{$R *.dfm} 
procedure TForm1.Button1Click(Sender: TObject); 
var 
A:Service1Soap; 
B:WideString; 
XMLDoc: IXMLDocument; 
begin 
A := HTTPRIO1 as Service1Soap; 
B := A.GetPersonTable; 
Memo1.Lines.Add( B ); 
ClientDataset1.Active := FALSE; 
XMLDoc := NewXMLDocument; 
XMLDoc.Encoding := SUTF8; 
XMLDoc.LoadFromXML(B); 
XMLTransformProvider1.TransformRead.SourceXmlDocument := XMLDoc.GetDOMDocument; 
ClientDataset1.Active := TRUE; 
end; 
end. 

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.NET WebService代码

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using System; 
using System.Collections; 
using System.ComponentModel; 
using System.Data; 
using System.Diagnostics; 
using System.Web; 
using System.Web.Services; 
using System.Data.OracleClient; 
using System.IO; 
namespace WS0622 
{ 
/// <summary> 
/// Service1 的摘要说明。 
/// </summary> 
public class Service1 : System.Web.Services.WebService 
{ 
public Service1() 
{ 
//CODEGEN: 该调用是 ASP.NET Web 服务设计器所必需的 
    InitializeComponent(); 
} 
#region 组件设计器生成的代码 
//Web 服务设计器所必需的 
private IContainer components = null; 
/// <summary> 
/// 设计器支持所需的方法 - 不要使用代码编辑器修改 
/// 此方法的内容。 
/// </summary> 
private void InitializeComponent() 
{ 
} 
/// <summary> 
/// 清理所有正在使用的资源。 
/// </summary> 
protected override void Dispose( bool disposing ) 
{ 
if(disposing && components != null) 
{ 
components.Dispose(); 
} 
base.Dispose(disposing); 
} 
#endregion 
// WEB 服务示例 
// HelloWorld() 示例服务返回字符串 Hello World 
// 若要生成，请取消注释下列行，然后保存并生成项目 
// 若要测试此 Web 服务，请按 F5 键 
[Serializable] 
public class Person 
{ 
public Person() 
{ 
} 
public Person(string name,string gender) 
{ 
this.Name=name; 
this.Gender=gender; 
} 
public string Name=""; 
public string Gender=""; 
} 
[WebMethod(CacheDuration=60)] 
public Person[] GetPersons() 
{ 
Person Alice=new Person("Alice","Female"); 
Person Bob=new Person("Bob","Male"); 
Person Chris=new Person("Chris","Female"); 
Person Dennis=new Person("Dennis","Male"); 
return new Person[]{Alice,Bob,Chris,Dennis}; 
} 
[WebMethod] 
public string GetPersonTable() 
{ 
DataTable table=new DataTable("Person"); 
table.Columns.Add("Name"); 
table.Columns.Add("Gender"); 
table.Rows.Add(new string[2]{"Alice","Female"}); 
table.Rows.Add(new string[2]{"Bob","Male"}); 
table.Rows.Add(new string[2]{"Chris","Female"}); 
table.Rows.Add(new string[2]{"Dennis","Male"}); 
table.Rows.Add(new string[2]{"Eric","Male"}); 
DataSet dataset=new DataSet("PersonTable"); 
dataset.Tables.Add(table); 
System.Text.StringBuilder strbuilder=new System.Text.StringBuilder(); 
StringWriter writer=new StringWriter(strbuilder); 
dataset.WriteXml(writer,System.Data.XmlWriteMode.IgnoreSchema); 
return strbuilder.ToString(); 
} 
} 
}