完全入門現(xiàn)在Internet正在不斷地發(fā)展著互聯(lián)網應用剛開始的時候

Web第一章Webservice簡Internet正在不斷地發(fā)展著，在互聯(lián)網應用剛開始的時候，我們?yōu)g覽的網頁只是靜.net平臺給我們提供了一種運行環(huán)境，即公用語言運行環(huán)境（CLR，CommonLanguageRuntime序開發(fā)者和VB程序員來說，這將是一致、熟悉的。這種模型是可以重復使用，也可以再。ASP.NET使用.asmxWebServices的支持。.asmx文件和.aspx文件一樣都屬于文本文件。它包含在.aspx文件之中，成為ASP.NET應用程序的一部分。下面舉一個簡單的例子來介紹.asmx文件，我們還是從“o，World”這個經文件名：webservice\sisam.asmx<%@WebServiceLanguage="VB"Class="oWorld"%>ImportsSystem.Web.ServicesPublicFunction<WebMethod()>SayoWorld()AsStringReturn("oWorld")EndClass類來源于基類WebService，而且應該是public類型。么這個方法就不能從service中。一個局部應用可以使用任何的public類型的類，但是只有具備[WebMethod]的類才可以通過SOAP被地。service的請求發(fā)生時，.asmxASP.NET運行環(huán)境所編譯。隨后的 將代碼保存為 Bar這時，看到關于這個WebService的公用方法－也就是那些標記為在InternetExplorer的地址欄中輸入后，將產生基于服務描述語言（ServiceDescriptionLanguage：SDL）XML文件。這個SDL文件非常重要，客戶端就是使用它來service。如簡單對象協(xié)議SOAP（SimpleObjectAccessProtocol）和HTTP這樣的開放協(xié)議標準ASP.NETWebServices。當然，這也需用高水平地合成ASP.NETWebServices和這種客戶端技術。SDK中有一個工具叫做WebServiceUtil.exe，我們可以使用它來一個WebServices創(chuàng)建一個叫做oWorld.cs的類： 這個類看起來與前面創(chuàng)建的類非常相似。它包含一個方法Say 同樣為了對照方便，我們列出了使用VB、C#以及JScript三種語言編寫的代碼：oWorldmyoWorld=new DimmyoWorldAsNewvarmyoWorld:oWorld=newoWorld();通過上面的例程，你可能對WebServices有了初步的印象。下面，介紹WebServices議時WebServices支持的數(shù)據(jù)類型：也即標準基礎類型，包括：String、Int32、Decimal、DateTime(類似XML 中的timeInstant)、DateTime(類似XML中的date)、DateTime(類似XML中的time)以及blue=2[]ADO.NETDataSet類型。DataSetsXmlNodeXML文檔片斷的內存表示，就說，""就可以在一個XmlNode類型變量XmlNodes作為參數(shù)傳遞，以SOAP兼容方式附加到傳遞給WebServicesXML文檔上。返回值也是同樣原(有限的Int32、String、DateTime、TimeSpan、UInt16、UInt32、UInt64和"publicenumcolorred=1,blue=2類，這可以通過設置WebService標識的Class屬性來實現(xiàn)，代碼如下：<%@WebServiceLanguage="VB"Class="DataTypes"%>ImportsSystemPublicEnumModeEOn=EndEnumPublicClassPublicPriceAsDoubleEndPublicClassReturn oEnd Return" EndFunctionDimIAsIntegerForI=0toA(I)=EndEndFunctionDimMyOrderAsNewEndFunctionDimMyOrder(2)AsOrderMyOrder(0)=NewOrder()MyOrder(1)=NewOrder()EndFunctionEnd對于使用客戶端應用程序而言，使用WebServiceUtil生成工具配置這些數(shù)據(jù)類型是透明的。請看關于WebService的一個客戶端例程：{font:8ptverdana;}DimDAsDataTypes=NewDataTypes()Message1.InnerHtml=D.Say Message1.InnerHtml=Message1.InnerHtml&D.Say Message3.InnerHtml=Message3.InnerHtml&D.GetMode()DimMyIntArrayAsInteger()=DimMyStringAsString="ContentsoftheForI=0ToMyIntArray.Length-MyString=MyString&MyIntArray(I)&Message2.InnerHtml=Message2.InnerHtml&MyStringDimMyOrderAsOrder=D.GetOrder()Message4.InnerHtml=Message4.InnerHtml&"<BR>OrderID:"&MyOrder.OrderIDMessage4.InnerHtml=Message4.InnerHtml&"<BR>Price:"&MyOrder.PriceDimMyOrdersAsOrder()= Message5.InnerHtml=Message5.InnerHtml&"<BR>Price:"&MyOrders(0).PriceEndSub<bodystyle="font:10pt<h5>MethodsthatreturnaPrimitive(String):<h5>MethodthatreturnsanEnum:<h5>MethodthatreturnsaClass/Struct:在客戶端程序中，我們使用<%@ImportNamespace="DataTypesService"%>來引入DataTypesServiceDataTypesServiceImportsSystem.Xml.SerializationImportsSystem.Web.ServicesPublicClass PublicSubNew()EndPublicSayo()AsStringDimresults()AsObject=Me.Invoke("Sayo",NewObject(0){})ReturnCType(results(0),String)EndPublicFunctionBeginSayo(ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("Sayo",NewObject(0){},callback,asyncState)EndFunctionDimresults()AsObject=Me.EndInvoke(asyncResult)ReturnCType(results(0),String)End IsNullable:=true)>nameAsString)AsStringDimresults()AsObject=Me.Invoke("SayoName",NewObject(){name})ReturnCType(results(0),String)EndPublicFunctionBeginSay oName(ByValnameAsString,ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturn oName",NewObject(){name},EndPublicFunction oName(ByValasyncResultAsSystem.IAsyncResult)

Dimresults()AsObject=Me.EndInvoke(asyncResult)ReturnCType(results(0),String)End Dimresults()AsObject=Me.Invoke("GetIntArray",NewObject(0){})ReturnCType(results(0),Integer())EndPublicFunctionBeginGetIntArray(ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("GetIntArray",NewObject(0){},callback,asyncState)EndFunctionPublicFunctionEndGetIntArray(ByValasyncResultAsSystem.IAsyncResult)

Dimresults()AsObject=Me.EndInvoke(asyncResult)ReturnCType(results(0),Integer())End GetMode()AsModeDimresults()AsObject=Me.Invoke("GetMode",NewObject(0){})ReturnCType(results(0),Mode)EndPublicFunctionBeginGetMode(ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("GetMode",NewObject(0){},callback,asyncState)EndFunctionPublicFunctionEndGetMode(ByValasyncResultAsSystem.IAsyncResult)AsModeDimresults()AsObject=Me.EndInvoke(asyncResult)EndFunction GetOrder()AsOrderDimresults()AsObject=Me.Invoke("GetOrder",NewObject(0){})ReturnCType(results(0),Order)EndPublicFunctionBeginGetOrder(ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("GetOrder",NewObject(0){},callback,asyncState)EndFunctionPublicFunctionEndGetOrder(ByValasyncResultAsSystem.IAsyncResult)AsOrderDimresults()AsObject=Me.EndInvoke(asyncResult)EndFunction Dimresults()AsObject=Me.Invoke("GetOrders",NewObject(0){})ReturnCType(results(0),Order())EndPublicFunctionBeginGetOrders(ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("GetOrders",NewObject(0){},callback,asyncState)EndFunctionPublicFunctionEndGetOrders(ByValasyncResultAsSystem.IAsyncResult)AsOrder()Dimresults()AsObject=Me.EndInvoke(asyncResult)EndFunctionEnd [Namespace]:="",IsNullable:=false)>ModeEnd [Namespace]:="",IsNullable:=true)>Order PriceAsDoubleEndClassvb文件中，我們定義了一個名字空間DataTypesService。請看vb文件的其中一段代碼段：PublicFunction odAttribute("")>Sayo()AsStringDimresults()AsObject=Me.Invoke("Say o",NewObject(0){})ReturnCType(results(0),String)EndPublicFunctionBeginSayo(ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("Sayo",NewObject(0){},callback,EndPublicFunctionEndSayo(ByValasyncResultAsSystem.IAsyncResult)AsStringDimresults()AsObject=Me.EndInvoke(asyncResult)ReturnEnd要生成上面的名字空間，我們使用webserviceutil.exe來編譯。 5.1.1中，webservice文件后綴名采用.asmx，開始應使用<%@WebService…%>申明，接著System.Web.Services命名空間，然后定義一個前面加上WebMethod屬性。第二章一個簡單的WebService案在這個例子中，定義一個mathservice類，來對兩個數(shù)字分別進行加，減，乘，除。當然這個類需要從基類webservice中繼承。請先看該程序的源代碼：<%@WebServiceLanguage="VB"Class="MathService"%>ImportsSystemPublicClassMathService:InheritsPublicFunction<WebMethod()>Add(AAsInteger,BAsInteger)AsIntegerReturnA+BEndReturnA-BEndFunctionPublicFunction<WebMethod()>Multiply(AAsInteger,BAsInteger)AsIntegerReturnA*BEndPublicFunction<WebMethod()>Divide(AAsInteger,BAsInteger)AsIntegerIfB=0Return-1EndIfEndFunctionEnd一個類（ DimOp1AsInteger=0DimOp2AsInteger=PublicSubSubmit_Click(SenderAsObject,EAsEventArgs)Op2=CatchExpAsException'IgnoredEndDimServiceAsMathService=NewMathService()Select(CType(sender,Control).ID)Case"Add"Result.Text="<b>Result</b>="&Service.Add(Op1,Op2).ToString()Case"Subtract":Result.Text="<b>Result</b>="&Service.Subtract(Op1,Op2).ToString()Case"Multiply":Result.Text="<b>Result</b>="&Service.Multiply(Op1,Op2).ToString()Case"Divide":Result.Text="<b>Result</b>="&Service.Divide(Op1,Op2).ToString()EndSelectEnd<bodystyle="font:10pt<h4>UsingaSimpleMathService<formOperand1:<br><asp:TextBoxid="Operand1"Text="15"runat="server"/><br>Operand2:<br><asp:TextBoxid="Operand2"Text="5"runat="server"/><p> <inputtype="submit"id="Subtract"value="Subtract"OnServerClick="Submit_Click"<inputtype="submit"id="Multiply"value="Multiply"OnServerClick="Submit_Click" sdl文件，當然這個文件不用手工輸入，我們在瀏覽一個.asmx的時候，在后綴名后直接加上？sdl可以自動生成sdl文件。ImportsSystem.Xml.SerializationImportsSystem.Web.ServicesNamespaceMathServiceSpacePublicClass PublicSubNew() ""&End <System.Xml.Serialization.XmlElementAttribute("A",IsNullable:=false)>aAsInteger,<System.Xml.Serialization.XmlElementAttribute("B",IsNullable:=false)>bAsInteger)AsDimresults()AsObject=Me.Invoke("Add",NewObject(){a,b})ReturnCType(results(0),Integer)EndPublicFunctionBeginAdd(ByValaAsInteger,ByValbAsInteger,ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("Add",NewObject(){a,b},callback,asyncState)EndFunctionPublicFunctionEndAdd(ByValasyncResultAsSystem.IAsyncResult)AsIntegerDimresults()AsObject=Me.EndInvoke(asyncResult)EndFunction Subtract(ByVal<System.Xml.Serialization.XmlElementAttribute("A",IsNullable:=false)>aAsInteger,ByVal<System.Xml.Serialization.XmlElementAttribute("B",IsNullable:=false)>bAsDimresults()AsObject=Me.Invoke("Subtract",NewObject(){a,b})ReturnCType(results(0),Integer)EndPublicFunctionBeginSubtract(ByValaAsInteger,ByValbAsInteger,ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("Subtract",NewObject(){a,b},callback,asyncState)EndFunctionPublicFunctionEndSubtract(ByValasyncResultAsSystem.IAsyncResult)AsIntegerDimresults()AsObject=Me.EndInvoke(asyncResult)EndFunction Multiply(ByVal<System.Xml.Serialization.XmlElementAttribute("A",IsNullable:=false)>aAsInteger,ByVal<System.Xml.Serialization.XmlElementAttribute("B",IsNullable:=false)>bAsInteger)AsIntegerDimresults()AsObject=Me.Invoke("Multiply",NewObject(){a,b})ReturnCType(results(0),Integer)EndPublicFunctionBeginMultiply(ByValaAsInteger,ByValbAsInteger,ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("Multiply",NewObject(){a,b},callback,asyncState)EndFunctionPublicFunctionEndMultiply(ByValasyncResultAsSystem.IAsyncResult)AsIntegerDimresults()AsObject=Me.EndInvoke(asyncResult)EndFunction Divide(ByVal<System.Xml.Serialization.XmlElementAttribute("A",IsNullable:=false)>aAsInteger,ByVal<System.Xml.Serialization.XmlElementAttribute("B",IsNullable:=false)>bAsInteger)AsIntegerDimresults()AsObject=Me.Invoke("Divide",NewObject(){a,b})ReturnCType(results(0),Integer)EndPublicFunctionBeginDivide(ByValaAsInteger,ByValbAsInteger,ByValcallbackAsSystem.AsyncCallback,ByValasyncStateAsObject)AsSystem.IAsyncResultReturnMe.BeginInvoke("Divide",NewObject(){a,b},callback,asyncState)EndFunctionPublicFunctionEndDivide(ByValasyncResultAsSystem.IAsyncResult)AsIntegerDimresults()AsObject=Me.EndInvoke(asyncResult)EndFunctionEndClass 5.2.1webservice服務的步驟和注意事項，雖然這個例子和實際使用的應用環(huán)境有第三章數(shù)據(jù)我們的這個例子說明了 一個基于XML技術的強大的數(shù)據(jù)分離技術能夠WebService方法返回。DataSet能夠在一個智能化的結構中復雜的信息和關系，這另外一個返回字體大小的列表。方法把兩個結果用一個DataSet來，并返回一個DataSet中的“Table“表的行數(shù)。雖然這個方法執(zhí)行起來有點簡單，但是ImportsPublicFunction<WebMethod()>Getcolor()AsDataSetDimMyConnectionAsSQLConnection=New mand1As mand=Newmand("select*fromcolor",MyConnection) mand2As mand=Newmand("select*fromsize",MyConnection)DimDSAsNewmand2.FillDataSet(DS,"size")ReturnDSEndFunctionPublicFunctionWebMethodPutcolor(DSAsDataSetAsIntegerEndFunction文件保存為webservice.asmx，放在虛擬 <%@WebServiceLanguage="VB"Class="DataService"%>ImportsSystemImportsImportsPublicClassDataServicePublicFunctionWebMethodGetcolorAsDat