sharepoint 自定义字段实现省市联动

最后实现效果如下：

设置栏如下：

解决方案结构如下：


fldtypes_RoyCustomField.xml 内容如下：

<?xml version="1.0" encoding="utf-8" ?>
<FieldTypes>
  <FieldType>
    <Field Name="TypeName">RoyCustomField</Field>
    <Field Name="ParentType">Text</Field>
    <Field Name="TypeDisplayName">RoyCustomField</Field>
    <Field Name="TypeShortDescription">RoyCustomField</Field>
    <Field Name="UserCreatable">TRUE</Field>
    <Field Name="FieldTypeClass">RoyCustomField.RoyCustomField,$SharePoint.Project.AssemblyFullName$</Field>
  </FieldType>
</FieldTypes>

RoyCustomField.cs 内容如下：

using Microsoft.SharePoint;
using Microsoft.SharePoint.WebControls;
using System.Web.UI.WebControls;
using System.Web.UI;
using System;
namespace RoyCustomField
{
    public class RoyCustomField : SPFieldText
    {
        public RoyCustomField(SPFieldCollection field, string strFieldName)
            : base(field, strFieldName)
        {
        }
        public RoyCustomField(SPFieldCollection field, string strFieldName, string strDispName)
            : base(field, strFieldName, strDispName)
        {
        }
            

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


    public class RoyText : BaseFieldControl
    {

        private DropDownList _ddlProvince;
        private DropDownList _ddlCity;
        #region Province of autoPostBack
        void Province_SelectedIndexChanged(object sender, EventArgs e)
        {
            _ddlCity.Items.Clear();
            if (_ddlProvince.SelectedValue.ToString() == "河北省")
            {
                _ddlCity.Items.Add(new ListItem("石家庄市", "石家庄市"));
            }
            else if (_ddlProvince.SelectedValue.ToString() == "山东省")
            {
                _ddlCity.Items.Add(new ListItem("济南市", "济南市"));
            }
            else
            {
                _ddlCity.Items.Add(new ListItem("北京市", "北京市"));
            }
        }
        #endregion
        protected override void CreateChildControls()
        {

            base.CreateChildControls();
            this.TemplateContainer.FindControl("_ddlProvince");
            _ddlProvince = new DropDownList();
            _ddlProvince.Items.Add(new ListItem("河北省", "河北省"));
            _ddlProvince.Items.Add(new ListItem("山东省", "山东省"));

            _ddlProvince.AutoPostBack = true;
            _ddlProvince.SelectedIndexChanged += Province_SelectedIndexChanged;
            this.Controls.Add(_ddlProvince);
            this.Controls.Add(new LiteralControl(" - "));
            this.TemplateContainer.FindControl("_ddlCity");
            _ddlCity = new DropDownList();
            _ddlCity.Items.Add(new ListItem("石家庄市", "石家庄市"));
            _ddlCity.Items.Add(new ListItem("济南市", "济南市"));
            this.Controls.Add(_ddlCity);
        }

        
        public override object Value
        {
            get
            {
                this.EnsureChildControls();
                return _ddlProvince.Text+"-"+_ddlCity.Text;
            }
            set
            {
                string fv = (string)this.ItemFieldValue;
                if (fv.Contains("-"))
                {
                    string[] all = fv.Split('-');
                    _ddlProvince.Text = all[0];
                    _ddlCity.Text = all[1];
                }
            }
        }
    }
}

注意事项：

1.xml的文件名必须以fldtypes_开头，否则不能识别。

2.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。

本文参考：http://www.cnblogs.com/Roy_Cao/archive/2012/08/14/2637542.html