DropDownList的值去控制TextBox是否可编写-原创手记-慕课网

Web窗体上有两控件，DropDownList1，TextBox1，当DropDownList的值选择是YES的时候，TextBox1可编辑，当选择NO的时候，TextBox1的值为空，并且不能编辑，该如何实现?

效果：

.aspx:

View Code <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        <asp:DropDownList ID="DropDownListYesNo" runat="server" AutoPostBack="true" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
        </asp:DropDownList>
        <asp:TextBox ID="TextBox1" runat="server" Enabled="true"></asp:TextBox>
    </form>
</body>
</html>

.aspx.cs:

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

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            Data_Binding();
        }
    }

    private void Data_Binding()
    {
        this.DropDownListYesNo.DataSource = GetData().Select(yn => new { value = yn }).ToList();
        this.DropDownListYesNo.DataTextField = "value";
        this.DropDownListYesNo.DataBind();
    }

    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        switch (this.DropDownListYesNo.SelectedItem.Text)
        {
            case "YES":
                this.TextBox1.Enabled = true;
                break;
            case "NO":
                this.TextBox1.Enabled = false;
                this.TextBox1.Text = string.Empty;
                break;
        }
    }

    private List<string> GetData()
    {
        List<string> yn = new List<string>();
        yn.Add("YES");
        yn.Add("NO");
        return yn;
    }
}