完全用编码实现gridview创建和clounms的添加Word文件下载.docx

完全用编码实现gridview创建和clounms的添加Word文件下载.docx

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SqlDataSource1.UpdateCommand=

updateemployeessetfirstname=@FirstName,lastname=@LastNamewhereemployeeid=@EmployeeID"

SqlDataSource1.UpdateParameters.Add（"

@FirstName"

"

）;

@LastName"

@EmployeeID"

if（!

IsPostBack）

GridView1.DataSourceID="

SqlDataSource1"

GridView1.AutoGenerateColumns=false;

GridView1.DataKeyNames=newstring[]{"

EmployeeID"

};

GridView1.AllowPaging=true;

GridView1.AllowSorting=true;

GridView1.PageSize=5;

BoundFieldbf1=newBoundField（）;

BoundFieldbf2=newBoundField（）;

BoundFieldbf3=newBoundField（）;

bf1.HeaderText="

EmployeeID"

bf1.DataField="

bf1.ReadOnly=true;

bf1.SortExpression="

bf2.HeaderText="

FirstName"

bf2.DataField="

FirstName"

bf2.SortExpression="

bf3.HeaderText="

LastName"

bf3.DataField="

LastName"

bf3.SortExpression="

CommandFieldcf=newCommandField（）;

cf.ButtonType=ButtonType.Button;

cf.ShowCancelButton=true;

cf.ShowEditButton=true;

GridView1.Columns.Add（bf1）;

GridView1.Columns.Add（bf2）;

GridView1.Columns.Add（bf3）;

GridView1.Columns.Add（cf）;

}

Part2

Introduction

InPart1 

youlearnedtocreateBoundFieldsandCommandFieldsdynamically.Oftenyourgridlayoutisbeyondthecapabilitiesofin-builtcolumntypesandyouneedtouseTemplateFields.Forexample,let'

ssayyouarecreatingaproductcatalog. 

Certainlynormal 

tabularlayoutisnotsuitablehereasyouwanttodisplayeachrecordinahighlycustomizedformat.Templatefieldscancomehandyinsuchsituations.InthisarticleIamgoingtoillustratehowtemplatefieldscanbeaddeddynamically.Youwilllearntwotechniquesofdoingso:

∙UsingLoadTemplate（）method

∙Bycreatingacustomtemplateclass

AddingTemplateFieldsUsingLoadTemplate（）Method

InordertoworkwiththisexampleyouneedtocreateanewwebsiteinVisualStudio.DraganddropaGridViewonthedefaultpage.AlsodraganddropanSqlDataSourcecontrol.Wewillbesettingvariouspropertiesofthesecontrolsviacode.InthefirstmethodofaddingtemplatefieldswewillbeusingLoadTemplate（）method.TheLoadTemplate（）methodisavailabletoalltemplatecontrolsincludingthePage.Itaccepts 

virtualpathofafileandloadsthetemplatespecifiedtherein.ThereturnvalueofLoadTemplate（）isanobjectthatimplementsITemplateinterface.

InourexamplewewillcreatethetemplateinaUserControl.Todoso,addanewWebUserControltothewebsiteandnameitasItemTemplate.ascx.Keyinthefollowingmarkuptoit.

<

%@ControlLanguage="

C#"

AutoEventWireup="

true"

CodeFile="

ItemTemplate.ascx.cs"

Inherits="

ItemTemplate"

%>

asp:

LabelID="

Label1"

runat="

server"

Text='

%#Eval（"

）%>

'

>

/asp:

Label>

Label2"

Label3"

Noticeabovemarkupcarefully.ItcontainsthreeLabelcontrols.TheTextpropertyofeachLabelisboundwithEmployeeID,FirstNameandLastNamecolumnsofEmployeestablerespectively.TheEval（）expressionisonewaydatabindingexpressionofASP.NETandacceptsthenameofthecolumntobind.ThisusercontrolwillactasourItemTemplatelater.

NowopenthecodebehindfileofthedefaultwebformandkeyinthefollowingcodeinPage_Loadeventhandler.

SqlDataSource1.ConnectionString=

SqlDataSource1.SelectCommand=

TemplateFieldtf1=newTemplateField（）;

tf1.ItemTemplate=LoadTemplate（"

ItemTemplate.ascx"

GridView1.Columns.Add（tf1）;

Thecode 

pointstheConnectionStringpropertyofSQLdatasourcecontroltoNorthwinddatabase.TheSelectCommandpropertyspecifiesaSELECTstatementthatfetchesEmployeeID,FirstNameandLastNamecolumnsofEmployeestable.Next,itsetsDataSourceIDpropertyofGridViewcontroltotheIDofSQLDataSourcecontrol.Also,AutoGenerateColumnspropertyissettofalseaswewillbeaddingcolumnsprogrammatically.Nextfewlinesareimportant.ThecodethencreatesaninstanceofTemplateFieldclass.TheTemplateFieldclassrepresentsatemplatecolumnofGridViewclass.TheItemTemplatepropertyofTemplateFieldclassisthensettothereturnvalueofLoadTemplate（）method.TheLoadTemplate（）methodacceptsavirtualpathofthefilecontainingtemplatetobeloaded（ItemTemplate.ascxinourcase）.TheTemplateFieldisthenaddedtotheColumnscollectionofGridViewcontrol.

Runthewebformandyourbrowsershoulddisplaysomethingasshownbelow:

Noticehowthetemplatespecifiedintheusercontrolisapplied.Also,noticethatheaderisshownblankbecausewedidnotspecifiedHeaderTemplate.Youcaneitherspecifyitorturntheheaderoff.

AddingTemplateFieldUsingCustomTemplateClass

NowthatyouknowhowtouseLoadTemplate（）methodlet'

smovetoanotherpossibility.YoulearntinthelastexamplethatLoadTemplate（）methodreturnsanobjectthatimplementsITemplateinterface.YouyourselfcancreatesuchaclassanduseitdirectlyinyourcodeinsteadofusingLoadTemplate（）method.

TobeginwithaddanewclassnamedMyTemplatetoApp_Codefolder.KeyinthefollowingcodetoMyTemplateclass.

publicclassMyTemplate:

ITemplate

privatestringcolname;

publicMyTemplate（stringcolname）

{

this.colname=colname;

}

publicvoidInstantiateIn（Controlcontainer）

LiteralControll=newLiteralControl（）;

l.DataBinding+=newEventHandler（this.OnDataBinding）;

container.Controls.Add（l）;

publicvoidOnDataBinding（objectsender,EventArgse）

LiteralControll=（LiteralControl）sender;

GridViewRowcontainer=（GridViewRow）l.NamingContainer;

l.Text=（（DataRowView）container.DataItem）[colname].ToString（）;

ThecodecreatesaclasscalledMyTemplatethatimplementsITemplateinterface.TheITemplateinterfacecontainsasinglemethod-InstantiateIn（）-thatyoumustimplement.Thecodethendeclaresastringvariabletoholdacolumnnametobedisplayed.Thecolumnnameissetintheconstructoroftheclass.ThenInstantiateIn（）methodisimplemented.ThemethodreceivesanobjectoftypeControlthatrepresentscontainerorparentcontrol.InsidewecreateaLiteralControlandattachaneventhandler（OnDataBinding）toitsDataBindingevent.ThiseventisraisedwhenthecontainercontrolcallsDataBind（）methodonitself.TheLiteralControlisthenaddedtotheControlscollectionofthecontainercontrol.

TheOnDataBinding（）eventhandlerdoesthejobofdatabindingtheLiteralControlwiththerequireddata.ItthengetsareferencetotherowinwhichthecontrolisbeingaddedusingNamingContainerproperty.Finally,TextpropertyofLiteralControlissettothevalueofdatabasecolumnasspecifiedintheconstructor.Thiscompletesourcustomtemplateclass.

Nowaddanewwebformtothesamewebsite.DraganddropaGridViewandSqlDataSourcecontrolasbefore.AddthefollowingcodeinthePage_Loadeventhandleroftheform.

initialcatalog=northwind;

integratedsecurity=true"

MyTemplatet1=newMyTemplate（"

tf1.HeaderText="

tf1.ItemTemplate=t1;

TemplateFieldtf2=newTemplateField（）;

MyTemplatet2=newMyTemplate（"

tf2.HeaderText="

tf2.ItemTemplate=t2;

GridView1.Columns.Add（tf2）;

ThecodesetsthepropertiesofSqlDataSourceandGridViewasbefore.Noticethecodemarkedinboldletters.ThecodecreatesaninstanceofTemplateFieldclassasbefore.ThistimetheItemTemplatepropertyofTemplateFieldissettoanewinstanceofMyTemplateclass.Thecolumnnames-FirstNameandLastName-arepassedintheconstructor.Finally,thetemplatefieldsareaddedtotheColumnscollectionofGridViewclass.

Thefollowingscreenshotshowsasamplerunoftheabove 

webform.

That'

sit!

Happycoding.