FileUpload文件上传

页面代码

    <form id="form1" runat="server">    <div>        <asp:Image ID="imagePic" runat="server" /><br />        <asp:FileUpload ID="fileUpload" runat="server" />        <asp:Button ID="btnUpload" runat="server" Text="上传" OnClick="btnUpload_Click" />        <asp:Label ID="lblMessage" runat="server" Text=""></asp:Label>    </div>    </form>后端代码：
        PRotected void btnUpload_Click(object sender, EventArgs e)        {            if (fileUpload.HasFile)            {             //获取上传的文件名                string filename = fileUpload.FileName;                //获取长传文件的文件后最名                string fileFix = filename.Substring(filename.LastIndexOf('.') + 1).ToLower();                if (fileFix != "png" && fileFix != "jpg" && fileFix != "jpeg" && fileFix != "gif")                {                    this.lblMessage.Text = "上传的图片不是图片类型文件！";                }                else                {                    fileUpload.SaveAs(Server.MapPath(".") + "//UploadPic//" + filename);                    this.imagePic.ImageUrl = "~/UploadPic/" + filename;                    this.lblMessage.Text = "图片长传成功！";                }            }        }