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！";
                }
            }
        }