调试易

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">&lt;img src=images/1.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="2">&lt;img src=Images/2.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="3">&lt;img src=Images/3.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="4">&lt;img src=Images/4.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="5">&lt;img src=Images/5.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="6">&lt;img src=Images/6.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="7">&lt;img src=Images/7.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="8">&lt;img src=Images/8.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="9">&lt;img src=Images/9.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="10">&lt;img src=Images/10.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="11">&lt;img src=Images/11.gif&gt;</asp:ListItem>
                        <asp:ListItem Value="12">&lt;img src=Images/12.gif&gt;</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" />
                    &nbsp;&nbsp;
                    <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.aspx 1
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。。