GridView中实现DropDownList联动

https://www.cnblogs.com/yangwujun/p/5394507.html

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
//如果是数据绑定行
if (e.Row.RowType == DataControlRowType.DataRow)
{
DropDownList ddlParent = (DropDownList)e.Row.FindControl("ddlParent");
GetParent(ddlParent);
}
}

private void GetParent(DropDownList ddl)
{
    string sql = "select * from Models where ParentModuleID=0";
    DataTable dt = DB.CreateDT(sql);
    ddl.DataTextField = "ModuleName";
    ddl.DataValueField = "ID";
    ddl.DataSource = dt;
    ddl.DataBind();
}
protected void ddlParent_SelectedIndexChanged(object sender, EventArgs e)
{
    GridViewRow row = (GridViewRow)((sender) as Control).NamingContainer;
    DropDownList ddlParent = (sender) as DropDownList;

    int ddlParentID=Convert.ToInt32(ddlParent.SelectedValue);

    DropDownList ddlChildren = row.FindControl("ddlChildren") as DropDownList;
    GetChildren(ddlChildren,ddlParentID);
    
}

private void GetChildren(DropDownList ddl, int parentID)
{
    string sql = "select * from Models where ParentModuleID=" + parentID + "";
    DataTable dt = DB.CreateDT(sql);
    ddl.DataTextField = "ModuleName";
    ddl.DataValueField = "ID";
    ddl.DataSource = dt;
    ddl.DataBind();
}

}