<?xml version="1.0" encoding="utf-8" ?>

<FieldTypes>

<FieldType>

<Field Name="TypeName">VisitorRecord</Field>

<Field Name="ParentType">Text</Field>

<Field Name="TypeDisplayName">浏览次数</Field>

<Field Name="TypeShortDescription">每点击一次DispForm页，浏览次数+1</Field>

<Field Name="UserCreatable">TRUE</Field>

<Field Name="Sortable">TRUE</Field>

<Field Name="AllowBaseTypeRendering">TRUE</Field>

<Field Name="Filterable">TRUE</Field>

<Field Name="FieldTypeClass">VisitorRecord.VisitorRecord,VisitorRecord, Version=1.0.0.0, Culture=neutral, PublicKeyToken=a3d395e8da16bea6</Field>

<RenderPattern Name="DisplayPattern">

<Column/>

</RenderPattern>

</FieldType>

</FieldTypes>

class VisitorRecord : SPField

{

public VisitorRecord(SPFieldCollection fields, string fieldName)

: base(fields, fieldName)

{

Init();

}

public VisitorRecord(SPFieldCollection fields, string typeName, string displayName)

: base(fields, typeName, displayName)

{

Init();

}

void Init()

{

//设置在DisplayForm页显示

this.ShowInDisplayForm = true;

//设置在EditFrom页不显示

this.ShowInEditForm = false;

//在NewForm页不显示

this.ShowInNewForm = false;

}

public override BaseFieldControl FieldRenderingControl

{

get

{

BaseFieldControl vr1 = new VisitorRecordControl();

vr1.FieldName = this.InternalName;

return vr1;

}

}

}

class VisitorRecordControl : BaseFieldControl

{

public void UpdateItemFieldValue()

{

try

{

SPSecurity.RunWithElevatedPrivileges(delegate()

{

using (SPSite site = new SPSite(SPContext.Current.Site.ID))

{

using (SPWeb web = site.OpenWeb(SPContext.Current.Web.ID))

{

web.AllowUnsafeUpdates = true;

SPList list = web.Lists[this.ListId];

SPListItem item = list.GetItemById(this.ItemId);

if (item == null) return;

if (ItemFieldValue != null)

item[this.FieldName] = (Convert.ToInt32(this.ItemFieldValue.ToString()) + 1).ToString();

else

item[this.FieldName] = "1";

item.SystemUpdate();

web.AllowUnsafeUpdates = false;

}

}

});

}catch{}

}

protected override void Render(System.Web.UI.HtmlTextWriter output)

{

if (this.ControlMode == SPControlMode.Display)

{

this.UpdateItemFieldValue();

if (this.ItemFieldValue != null)

{

output.Write(this.ItemFieldValue.ToString());

}

else

{

output.Write("0");

}

}

}

}

单行文本 – SPFieldText

多行文本 – SPFieldMultiLineText

数字 – SPFieldNumber

货币 – SPFieldCurrency

是/否 – SPFieldBoolean

日期 - SPFieldDateTime

选项（单选） - SPFieldChoice

//判断输入值的有效性

public override string GetValidatedString(object value)

//重写字段默认值

public override string DefaultValue

//该字段是否允许被爬网

public override bool NoCrawl

//字段删除时执行的事件

public override void OnDeleting()

//字段添加后执行的事件

public override void OnAdded()

//字段更新后执行的事件

public override void OnUpdated()