上传图片代码。

前台是一个upload控件加一个按钮：
addline.aspx：

<tr>
    <td style=" 30px">&nbsp;<asp:Label ID="Label9" runat="server" Text="Picture URL:"></asp:Label></td>
    <td>&nbsp;<asp:TextBox ID="imgurl"
        runat="server">../img/Noimg.jpg</asp:TextBox>
    <asp:Label ID="addimg" runat="server" ForeColor="Red"></asp:Label><br />
    <asp:Label ID="Label10" runat="server" Text="Choose PIC:"></asp:Label>
    <asp:FileUpload ID="imgurl1" runat="server" />
        <asp:Button
        ID="Button1" runat="server" OnClick="Button1_Click" Text="upload" /></td>
</tr>

addline.cs：

protected void Button1_Click(object sender, EventArgs e)
    {
        Boolean fileOK = false;
        String path = Server.MapPath("~/img/tour/");
        String url = "../img/tour/" + imgurl1.FileName;
        if (imgurl1.HasFile)
        {
            String fileExtension =
                System.IO.Path.GetExtension(imgurl1.FileName).ToLower();
            String[] allowedExtensions = 
                { ".gif", ".png", ".jpeg", ".jpg" };
            for (int i = 0; i < allowedExtensions.Length; i++)
            {
                if (fileExtension == allowedExtensions[i])
                {
                    fileOK = true;
                }
            }
        }

        if (fileOK)
        {
            
                imgurl1.PostedFile.SaveAs(path
                    + imgurl1.FileName);
                addimg.Text = "File uploaded!";
                imgurl.Text = url;
           
        }
        else
        {
            addimg.Text = "Cannot accept files of this type.";
        }
    }