无法将类型“string”隐式转换为“System.Web.UI.WebControls.TextBox”

C# code

public partial class Admin_AddNews : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {        if (!IsPostBack)        {            ListBind();        }    }    protected void Button1_Click(object sender, EventArgs e)    {        DateTime addtime = DateTime.Now;        SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings["constr"]);        string insr = "insert into News (NewsTitle,NewsClassID,NewsContent,NewsAddtime,NewsClick,NewsAuthor) values('" + Title.Text + "','" + DropDownList1.SelectedValue + "','" + NewsContent.Text.Trim() +"','" + addtime + "',0,'" + Author.Text + "')";        conn.Open();        SqlCommand cmd = new SqlCommand(insr, conn);        cmd.ExecuteNonQuery();        Label1.Text = "添加成功！";        Label1.Visible = true;        conn.Close();    }    public void ListBind()    {        SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings["constr"]);        string sql = "select * from NewsClass order by NewsID desc";        conn.Open();        SqlDataAdapter da = new SqlDataAdapter(sql, conn);        DataSet ds = new DataSet();        da.Fill(ds, "NewsClass");        DropDownList1.DataSource = ds.Tables["NewsClass"].DefaultView;        DropDownList1.DataTextField = "NewsClassName";        DropDownList1.DataValueField = "NewsID";        DropDownList1.DataBind();        conn.Close();    }    protected void Button2_Click(object sender, EventArgs e)    {        NewsContent.Text = "";        Title.Text = "";    }}

前台页面：
<%@ Page Language="C#" MasterPageFile="~/Admin/Admin.master" AutoEventWireup="true" //错误行..无语。
CodeFile="AddNews.aspx.cs" Inherits="Admin_AddNews" Title="Untitled Page" %>

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
<div style="text-align: center; font-size: 14px;">
<table style="height: 366px; width: 90%;">
<tr>
<td style="width: 72px; text-align: center;">
标题</td>
<td style="width: 100px; text-align: left;">
<asp:TextBox ID="Title" runat="server" Width="493px"></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="Title"
Display="Dynamic" ErrorMessage="不能为空"></asp:RequiredFieldValidator></td>
</tr>
<tr>
<td style="width: 72px; text-align: center;">
类别</td>
<td style="width: 100px; text-align: left">
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList></td>
</tr>
<tr>
<td style="width: 72px; text-align: center;">
作者</td>
<td style="width: 100px; text-align: left">
<asp:TextBox ID="Author" runat="server" Width="100px" MaxLength="20"></asp:TextBox>

<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="Author"
Display="Dynamic" ErrorMessage="不能为空"></asp:RequiredFieldValidator></td>
</tr>
<tr>

<td style="width: 72px" valign="top">
内容</td>
<td style="width: 100px; text-align: left">
<asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="NewsContent"
Display="Dynamic" ErrorMessage="还是说点什么吧"></asp:RequiredFieldValidator>
<asp:TextBox ID="NewsContent" runat="server" Height="500px" TextMode="MultiLine"
Width="500px"></asp:TextBox>
</td>
</tr>
<%-- <tr>
<td align="center">
留言表情</td>
<td>
<asp:RadioButtonList ID="Face" runat="server" Width="500px" RepeatColumns="6">
<asp:ListItem Value="1" Selected="True"><img src=images/1.gif></asp:ListItem>
<asp:ListItem Value="2"><img src=Images/2.gif></asp:ListItem>
<asp:ListItem Value="3"><img src=Images/3.gif></asp:ListItem>
<asp:ListItem Value="4"><img src=Images/4.gif></asp:ListItem>
<asp:ListItem Value="5"><img src=Images/5.gif></asp:ListItem>
<asp:ListItem Value="6"><img src=Images/6.gif></asp:ListItem>
<asp:ListItem Value="7"><img src=Images/7.gif></asp:ListItem>
<asp:ListItem Value="8"><img src=Images/8.gif></asp:ListItem>
<asp:ListItem Value="9"><img src=Images/9.gif></asp:ListItem>
<asp:ListItem Value="10"><img src=Images/10.gif></asp:ListItem>
<asp:ListItem Value="11"><img src=Images/11.gif></asp:ListItem>
<asp:ListItem Value="12"><img src=Images/12.gif></asp:ListItem>
</asp:RadioButtonList></td>
</tr>--%>
<tr>
<td style="width: 72px">
</td>
<td style="width: 100px; text-align: left">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="发表" />
  
<asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="清空" /></td>
</tr>
<tr>
<td colspan="2" style="text-align: center" rowspan="3">
<asp:Label ID="Label1" runat="server" Width="303px"></asp:Label><a href="Admin_Index.aspx">查看</a></td>

</tr>
<tr>
</tr>
<tr>
</tr>
</table>
<br />
</div>
</asp:Content>

错误4无法将类型“string”隐式转换为“System.Web.UI.WebControls.TextBox”E:\Student\Admin\AddNews.aspx1


小弟刚学C#几天，一早上就被这个留言板搞疯了.. 高手们救命。。

[解决办法]
TextBox.Text = "";
[解决办法]
你贴的代码貌似没有错误。
应该是某个TextBox控件设置显示内容时错了
eg: TextBox1.Text = "test";
你写成了
TextBox = "test";
[解决办法]
TextBox.Text=xxxx
[解决办法]
哪行出错应该为TextBox1.Text="";
取值TextBox1.Text
[解决办法]
应该赋值给text属性，而不控件
[解决办法]
对啊，你将string类型的变量赋值给一个TextBox控件，那肯定是要报错的，你应该TextBox.Text=XX这样就不会报错了
[解决办法]
楼主你现在贴出的代码里textbox控件没有错误，但是你的母版页里面很可能有textbox控件有错误，你自己也说是那行出错了。你看下你的母版页，查找下textbox，一个个textbox控件看过来吧，肯定是哪个
TextBox = "xxxxx";了，因为TextBox是个控件，它的属性text才能赋值，你不能直接把字符串赋值给TextBox。