SharePoint 2010 自定义 字段 类型--------省市区联动

最近有几个朋友问到了有关自定义字段类型的问题，为了让更多的人了解自定义字段类型的方法，特写一篇博客与大家分享，首先看一下解决方案目录

创建自定义类型分以下几个步骤：

第一步：添加SharePoint映射文件夹Xml，在Xml的文件名必须以fldtypes_开头，否则不能识别，为了更好的了解Xml里面的结构我们可以在服务器上打开，看一看系统是如何定义的。

第二步：开始省市定义联动，XML定义

<?xml version="1.0" encoding="utf-8" ?>
<FieldTypes>
  <FieldType>
    <Field Name="TypeName">ProvinceCityArea</Field>
    <Field Name="ParentType">Text</Field>
    <Field Name="TypeDisplayName">Province City Area</Field>
    <Field Name="TypeShortDescription">省市区联动</Field>
    <Field Name="UserCreatable">TRUE</Field>
    <Field Name="FieldTypeClass">
      SharePointProject_Custom_FieldsType_Controls.Controls.ProvinceCityArea,
      $SharePoint.Project.AssemblyFullName$
    </Field>
  </FieldType>
  <FieldType>
    <Field Name="TypeName">ProvinceCity</Field>
    <Field Name="ParentType">Text</Field>
    <Field Name="TypeDisplayName">Province City</Field>
    <Field Name="TypeShortDescription">省市联动</Field>
    <Field Name="UserCreatable">TRUE</Field>
    <Field Name="FieldTypeClass">
      SharePointProject_Custom_FieldsType_Controls.Controls.ProvinceCity,
      $SharePoint.Project.AssemblyFullName$
    </Field>
  </FieldType>
</FieldTypes>

第三步：创建ProvinceCityControl 类文件，并继承 BaseFieldControl，省市的数据来源是另一张表

代码主要重载 protected override void CreateChildControls()

using System.Web.UI;
using System.Web.UI.WebControls;
using Microsoft.SharePoint;
using Microsoft.SharePoint.WebControls;

namespace SharePointProject_Custom_FieldsType_Controls.Controls
{
    public class ProvinceCityControl : BaseFieldControl
    {
        private DropDownList _ddlProvince;
        private DropDownList _ddlCity;
        private SPWeb _web;
        private SPListCollection _listCollection;
        private SPList _list;
        private SPQuery _query;
        private SPListItemCollection _listItemCollection;

        protected override void CreateChildControls()
        {
            if (this.ControlMode == SPControlMode.Display)
            {
                this.Controls.Add(new LiteralControl("" + this.Value));
            }
            else
            {
                _ddlProvince = new DropDownList();
                _ddlCity = new DropDownList();
                using (_web = SPContext.Current.Web)
                {
                    _listCollection = _web.Lists;
                    _list = _listCollection.TryGetList(Consts.LIST_DICTIONARY);
                    if (_list != null)
                    {
                        #region Province
                        _query = new SPQuery();
                        _query.Query = string.Concat(
                            "<Where>",
                            "<Eq><FieldRef Name='Group_x003a_Title'/><Value Type='Lookup'>" + Consts.GROUP_PROVINCE + "</Value></Eq>",
                            "</Where>"
                            );
                        _query.ViewFields = string.Concat(
                            "<FieldRef Name='DictionaryName'/>",
                            "<FieldRef Name='Title'/>"
                            );
                        _listItemCollection = _list.GetItems(_query);
                        _ddlProvince.AutoPostBack = true;
                        _ddlProvince.SelectedIndexChanged += new EventHandler(Province_SelectedIndexChanged);
                        foreach (SPListItem item in _listItemCollection)
                        {
                            _ddlProvince.Items.Add(new ListItem(item["DictionaryName"].ToString(), item["Title"].ToString()));
                        }
                        #endregion

                        #region City
                        LoadCity();
                        #endregion

                    }

                }
                this.Controls.Add(_ddlProvince);
                this.Controls.Add(new LiteralControl("-"));
                this.Controls.Add(_ddlCity);
            }
        }

        #region Province of autoPostBack
        void Province_SelectedIndexChanged(object sender,EventArgs e)
        {
            LoadCity();
        }
        #endregion

        #region Load City
        void LoadCity()
        {
            _ddlCity.Items.Clear();
            _query = new SPQuery();
            _query.Query = string.Concat(
                "<Where><And>",
                "<Eq><FieldRef Name='Group_x003a_Title'/><Value Type='Lookup'>" + Consts.GROUP_CITY + "</Value></Eq>",
                "<BeginsWith><FieldRef Name='Title'/><Value Type='Text'>" + _ddlProvince.SelectedValue.ToString() + "</Value></BeginsWith>",
                "</And></Where>"
                );
            _listItemCollection = _list.GetItems(_query);
            foreach (SPListItem item in _listItemCollection)
            {
                _ddlCity.Items.Add(new ListItem(item["DictionaryName"].ToString(), item["Title"].ToString()));
            }
        }
        #endregion

        public override object Value
        {
            get
            {
                return base.Value;
            }
            set
            {
                base.Value = value;
            }
        }
    }
}

第四步：再创建一个类ProvinceCity ，并继承SPFieldText

using Microsoft.SharePoint;
using Microsoft.SharePoint.WebControls;

namespace SharePointProject_Custom_FieldsType_Controls.Controls
{
    public class ProvinceCity:SPFieldText
    {
        public ProvinceCity(SPFieldCollection fields, string fieldName) : base(fields, fieldName) { }
        public ProvinceCity(SPFieldCollection fields, string fieldType, string displayName) : base(fields, fieldType, displayName) { }

        public override BaseFieldControl FieldRenderingControl
        {
            get
            {
                BaseFieldControl fc = new ProvinceCityControl();
                fc.FieldName = this.InternalName;
                return fc;
            }
        } 
    }
}

如果要设置默认值请Override DefaultValue，如果要验证格式是否正确 请Override GetValidatedString
第五步：部署查看效果

第六步：创建栏查看效果

就这么简单，完成了，快来试吧。