文件无法使用c#ASP.NET保存在文件夹中

本文关键字：保存 存在 文件夹 NET c#ASP 文件 | 更新日期: 2023-09-27 18:00:43

我试图将文件保存在DB中，并使用c#保存在特定文件夹中，但我收到了以下错误：

错误：

System.NullReferenceException was unhandled by user code
  Message=Object reference not set to an instance of an object.
  Source=ODIYA_Doctor_Admin
  StackTrace:
       at ODIYA_Doctor_Admin.Module.Front_End_Management.banner.bnrSubmit_Click(Object sender, EventArgs e) in C:'ASP project'ODIYA_Doctor_Admin'ODIYA_Doctor_Admin'Module'Front_End_Management'banner.aspx.cs:line 82
       at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
       at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
       at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
       at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
       at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
       at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
  InnerException:

我的代码：

banner.aspx：

<div class="col-md-6 bannerimagefile">
                                                <label for="title" accesskey="T"><span class="required">*</span> Title</label>
                                                <div id="errTitle" style="display:none;" runat="server"></div>
                                                <asp:TextBox ID="txtBnrTitle" runat="server" size="30" value="" ></asp:TextBox>
                                                <label for="status" accesskey="S"><span class="required">*</span> Status</label>
                                                <asp:DropDownList ID="bnrStatus" runat="server" >
                                                <asp:ListItem Text="Select your status" Value="enable" Selected="True"></asp:ListItem>
                                                <asp:ListItem Text="Enable" Value="enable"></asp:ListItem>
                                                <asp:ListItem Text="Disable" Value="disable"></asp:ListItem>
                                                </asp:DropDownList>
                                                <label for="insertimage" accesskey="B"><span class="required">*</span> Banner Image</label>
                                                <asp:FileUpload runat="server" class="filestyle" data-size="lg" name="insertimage" id="FileUpload1" onchange="previewFile()" />
                                                <label for="bannerimage" accesskey="V"><span class="required">*</span> View Image</label>
                                                <div style="padding-bottom:10px;">
                                                    <asp:Image ID="bnrimgPhoto" runat="server" border="0" name="bannerimage" style="width:70px; height:70px;"   />
                                                </div>
                                                <div class="clear"></div>
                                            </div>
                                            <div class="col-md-6">
                                                <label for="shortdes" accesskey="V"><span class="required">*</span> Short Description</label>
                                                <asp:TextBox ID="bnrshortdes" runat="server" size="30" value="" ></asp:TextBox>
                                                <div id="bnrShtdesErrDiv" style="display:none;" runat="server"></div>
                                                <label for="description" accesskey="D"><span class="required">*</span> Description</label>
                                                 <asp:TextBox ID="txtBnrDesc" runat="server" name="description" cols="40" Rows="7" TextMode="MultiLine"></asp:TextBox>
                                                 <div id="bnrDesErrDiv" style="display:none;" runat="server"></div>
                                                 <asp:Button runat="server" Text="Submit" class="submit" ID="bnrSubmit" OnClick="bnrSubmit_Click" />
                                            </div>
                                        </div>
                                </div>
                            </div>

banner.aspx。cs:

protected void bnrSubmit_Click(object sender, EventArgs e)
        {
                if (txtBnrTitle.Text.Trim().Length > 0 && bnrStatus.SelectedItem.Text.Length > 0 && FileUpload1.ClientID.Length > 0 && bnrshortdes.Text.Trim().Length > 0 && txtBnrDesc.Text.Trim().Length > 0)
                {
                    string action = "";
                    if (bnrSubmit.Text == "Submit")
                    {
                        action = "insert";
                    }
                    if (bnrSubmit.Text == "Update")
                    {
                        action = "update";
                    }
                    objBannerBO.title = txtBnrTitle.Text.Trim();
                    objBannerBO.status = bnrStatus.SelectedValue.Trim();
                    string filename = FileUpload1.FileName;
                    FileUpload1.PostedFile.SaveAs(Server.MapPath(@"~'Upload'" + filename.Trim()));
                    string path = filename.Trim();
                    objBannerBO.image = path;
                    objBannerBO.shtdescription = bnrshortdes.Text.Trim();
                    objBannerBO.description = txtBnrDesc.Text.Trim();
                    objBannerBO.Created_By = Session["uid"].ToString();
                    if (action == "insert")
                    {
                        int result = objBannerBL.saveBannerDetails(objBannerBO, action);
                        if (result == 1)
                        {
                            Session["update"] = Server.UrlEncode(System.DateTime.Now.ToString());
                            ScriptManager.RegisterStartupScript(this, this.GetType(), "alert", "alert('Banner details Added Successfully!!')", true);
                            Response.Redirect("banner.aspx");
                        }
                        else
                        {
                            ScriptManager.RegisterStartupScript(this, this.GetType(), "alert", "alert('Banner details could not Added !!')", true);
                        }
                    }
                }
        }

错误实际上出现在FileUpload1.PostedFile.SaveAs(Server.MapPath(@"~'Upload'" + filename.Trim()));行。这里我需要将图像保存在文件夹和数据库中。请帮帮我。

文件无法使用c#ASP.NET保存在文件夹中

试试这个：

 if (FileUpload1.HasFile)
  {
    FileUpload1.SaveAs(Server.MapPath(@"~'Upload'" + filename));
  }

如果您使用的是Updatepanel，那么您必须将Trigger添加到您的更新面板中。

<Triggers>
<asp:PostBackTrigger ControlID="bnrSubmit" />
</Triggers>

还将下面的行添加到Page_Load

Page.Form.Attributes.Add("enctype", "multipart/form-data");
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