Question

我有一个 UserControl ，我正在尝试将我的GridView表导出为PDF。我能够很好地制作CSV文件，但在尝试制作PDF时出错。（我正在使用iTextSharp库）这是我得到的错误：

“格式为'GridView'的控件'DoNotAddList_1_GridView1'必须放在带有runat = server的表单标记内。”

我的html中有一个表单标记，我尝试将其添加到ascx文件中但没有任何效果。我发现很多人都收到此错误，大多数人都建议将其添加到ascx.cs文件的代码中：

public override void VerifyRenderingInServerForm(Control control) {     }

但是这给了我这个错误“找不到合适的方法来覆盖......”

我不知道该怎么办。我一直无法找到解决方案。请帮忙！！

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;
using iTextSharp.text.html;
using iTextSharp.text.html.simpleparser;

public partial class UserControls_DoNotAddListControl : System.Web.UI.UserControl
{
protected void PDF_Click(object sender, EventArgs e)
{   
    Response.ContentType = "application/pdf";
    Response.AddHeader("content-disposition",
     "attachment;filename=GridViewExport.pdf");
    Response.Cache.SetCacheability(HttpCacheability.NoCache);
    StringWriter sw = new StringWriter();
    HtmlTextWriter hw = new HtmlTextWriter(sw);
    GridView1.AllowPaging = false;
    GridView1.DataBind();
    GridView1.RenderControl(hw);
    StringReader sr = new StringReader(sw.ToString());
    Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);
    HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
    PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
    pdfDoc.Open();
    htmlparser.Parse(sr);
    pdfDoc.Close();
    Response.Write(pdfDoc);
    Response.End();
}
protected void CSV_Click(object sender, EventArgs e)
{
     Response.ClearContent();
    Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", "BloombergDaily.csv"));
    Response.ContentType = "application/text";
    GridView1.AllowPaging = false;
    GridView1.DataBind();
    StringBuilder strbldr = new StringBuilder();
    for (int i = 0; i < GridView1.Columns.Count; i++)
    {
        strbldr.Append(GridView1.Columns[i].HeaderText + ',');
    }
    strbldr.Append("\n");
    for (int j = 0; j < GridView1.Rows.Count; j++)
    {
        for (int k = 0; k < GridView1.Columns.Count; k++)
        {
            strbldr.Append(GridView1.Rows[j].Cells[k].Text + ',');
        }
        strbldr.Append("\n");
    }
    Response.Write(strbldr.ToString());
    Response.End();
}
}

这是我在aspx文件中的内容：

<form id="form1" runat="server" action="/">          
        <div id="donotadd" class="tableWrapper">
            <div id="tabs1">
                <p>
                    <div id="tabs-1" >                           
                        <div id="DoNotAddListMacro" class="dataTable table_Center">
                        <umbraco:Macro ID="Macro1" Alias="DoNotAddListControl" runat="server"></umbraco:Macro>
                        </div>                                                                          
                    </div>   
                </p>
            </div>    
        </div>            
    </form>

Answer 1

前段时间我遇到了同样的情况。我看到你已经覆盖了以下方法。但是你把这个方法放在你的用户控件中了吗？那将会给你＆＃34;找不到合适的方法来覆盖＆＃34;。需要在.aspx.cs文件中重写此方法，您将删除用户控件。

具有ExportPdf（）方法

的UserControl背后的代码

 protected void btnExportPdf_Click(object sender, EventArgs e)
    {
        System.Threading.Thread.Sleep(1000);
        ExportPdf();
    }

    protected void ExportPdf()
    {
        using (StringWriter sw = new StringWriter())
        {
            using (HtmlTextWriter hw = new HtmlTextWriter(sw))
            {
                //To export all pages
                gvCharges.AllowPaging = false;
                this.BindRepeater();

                gvCharges.RenderControl(hw);
                StringReader sr = new StringReader(sw.ToString());
                Document pdfDoc = new Document(PageSize.A2, 10f, 10f, 10f, 0f);
                HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
                PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
                pdfDoc.Open();
                htmlparser.Parse(sr);
                pdfDoc.Close();

                Response.ContentType = "application/pdf";
                Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.pdf");
                Response.Cache.SetCacheability(HttpCacheability.NoCache);
                Response.Write(pdfDoc);
                Response.End();
            }
        }
    }

这里是.ascx文件的来源

<asp:Button ID="btnExportPdf" runat="server" Text="Export to pdf" Visible = "false" 
    onclick="btnExportPdf_Click" CssClass="btn btn-primary" />

这里是.aspx的源代码，我把usercontrol放到了

 <div class="form-section-body">
     <table style="width: 100%">
         <tr>
             <td colspan="2" style="padding: 20px 5px 5px 5px;">
                 <uc2:PosTrans ID="PosTrans1" runat="server" />
             </td>
         </tr>
     </table>
 </div>

这里是.aspx.cs背后的代码，我将用户控件放到了

 namespace DFM.Dashboard
{
    public partial class Dashboard : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        public override void VerifyRenderingInServerForm(Control control)
        {
            /* Verifies that the control is rendered */
        }
    }

}

Answer 2

以下是我找到的解决方案：

protected void BtnPDF_Click(object sender, EventArgs e)
    {
        GridView gv = new GridView();
        gv.DataSource = SqlDataSource1;
        gv.DataBind();
        StringWriter sw = new StringWriter();
        HtmlTextWriter htw = new HtmlTextWriter(sw);

        gv.RenderControl(htw);

        var mem = new MemoryStream();

        Document document = new Document(PageSize.LETTER, 50, 50, 50, 50);
        PdfWriter.GetInstance(document,mem);

        document.Open();

        iTextSharp.text.html.simpleparser.HTMLWorker hw = new iTextSharp.text.html.simpleparser.HTMLWorker(document);
        hw.Parse(new StringReader(sw.ToString()));
        document.Close();

        Response.ClearContent();
        Response.ClearHeaders();
        Response.ContentType = "application/pdf";
        Response.AddHeader("Content-Disposition", "attachment; filename=" + DateTime.Now);

        Response.BinaryWrite(mem.ToArray());
        Response.End();
        Response.Flush();
        Response.Clear();
    }

Answer 3

我知道这可能是左边的字段，但你是否将用户控件放在带有runat =“server”属性的表单标签中？

<form runat="server">
<myprefix:MyControl runat="server" />
</form>

Answer 4

尝试这个。相应的地方控制类型

public override void VerifyRenderingInServerForm(Control control)
     {
         Macro grid = control as Macro ;
         if (grid != null && grid.ID == "Macro1")
             return;
         else
             base.VerifyRenderingInServerForm(control);

     }

<强>更新查看以下链接以获取完整示例

Export Html to Pdf using iTextSharp(GridView)

UserControl将GridView导出为PDF

4 个答案: