using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        TextBox food =new TextBox();
        food.ID="food";/////////////////////////为什么在load里的Text就是空的。
        Panel1.Controls.Add(food);
        Response.Write(food.Text);
    }
    protected void AddTextBox()
    {
        TextBox food;
        food=Panel1.FindControl("food")as TextBox;
        string[] foodText;
        CheckBox foodCheckbox;
        if(TextBox1.Text!="")
        {
            food.Text += TextBox1.Text + ",";
            foodText = food.Text.Split(',');
          /*foreach (string cbtext in foodText)
            {
                foodCheckbox = new CheckBox();
                foodCheckbox.Text = cbtext;
                Panel1.Controls.Add(foodCheckbox);
                Response.Write(cbtext);
            }*/
            for (int i = 0; i < foodText.Length - 1; i++)
            {
                foodCheckbox = new CheckBox();
                foodCheckbox.Text = foodText[i];
                Panel1.Controls.Add(foodCheckbox);

            }
        }
        TextBox1.Text = "";
  //  Response.Write(food.Text);
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        AddTextBox();
        
    }
}

在这个程序里为什么在lound函数里的food.Text就没有值呢，而在AddTextBox里的food.Text就有值，他们俩是一个控件啊。