export gridview have data to pdf failed and file not open

Hi Ahmed, 

It appears that you're facing issues when trying to export a large GridView to a PDF in an ASP.NET application. The problem might be occurring due to the data not being correctly passed to the server-side method or the method not being called at all. 

1. Ensure AJAX Call is Set Up Properly

Your AJAX call doesn't seem to be setup properly as it lacks url and type properties, and does not send data to the server-side method. Here’s how you can modify your AJAX call:

function ExportGridViewToPdf() {
    var tableData = [];
    var columns = [];

    // Get the data from the GridView
    $('#gvResults tr').each(function (index) {
        if (index === 0) {
            // Get the column names
            $(this).find('th').each(function () {
                columns.push($(this).text());
            });
        } else {
            var rowData = [];
            $(this).find('td').each(function () {
                rowData.push($(this).text());
            });
            tableData.push(rowData);
        }
    });

    // Make an AJAX call to the server-side method
    $.ajax({
        type: "POST",
        url: "YourPageName.aspx/ExportGridViewToPdf", // Modify with your actual page name and method
        contentType: "application/json; charset=utf-8",
        data: JSON.stringify({ gridData: tableData, columnNames: columns }),
        dataType: "json",
        success: function(response) {
            var blob = new Blob([response.d], {type: 'application/pdf'});
            var url = window.URL.createObjectURL(blob);
            var a = document.createElement('a');
            a.href = url;
            a.download = "GridView.pdf";
            document.body.append(a);
            a.click();
            a.remove();
            window.URL.revokeObjectURL(url);
        },
        error: function(xhr, status, error) {
            console.error("Error exporting PDF: " + xhr.responseText);
        }
    });
}

2. Server-Side Code Modification

Make sure that your server-side method is correctly configured to handle the request. Also ensure that [WebMethod] and [ScriptMethod(ResponseFormat = ResponseFormat.Json)] attributes are properly set up:

[System.Web.Services.WebMethod]
[System.Web.Script.Services.ScriptMethod(ResponseFormat = System.Web.Script.Services.ResponseFormat.Json)]
public static byte[] ExportGridViewToPdf(string[][] gridData, string[] columnNames)
{
    // existing code
}

Ensure that all the necessary PDF generation libraries (like iTextSharp) are correctly referenced in your project and are compatible with the version of .NET you are using.

Since you are handling a large amount of data, consider implementing a loading indicator or asynchronous processing notification on the client side to inform the user that the process is ongoing, especially if the generation might take some time.

Add logging on both the client-side and server-side to capture any failures or exceptions. This will help in identifying where the issue might be occurring (either during data transmission or PDF generation).

By ensuring these aspects are correctly implemented, your function should be able to handle the export of a large GridView to a PDF more effectively.

The issue might be due to the way the data is handled in the AJAX call and on the server side. Let's ensure the following:

1. The AJAX call is properly configured to send data to the server.
2. The server-side method correctly processes the data and returns it as a PDF file.
3. The client-side code correctly handles the received data and triggers the download.

function ExportGridViewToPdf() {
    var tableData = [];
    var columns = [];

    // Get the data from the GridView
    $('#gvResults tr').each(function (index) {
        if (index === 0) {
            // Get the column names
            $(this).find('th').each(function () {
                columns.push($(this).text());
            });
        } else {
            var rowData = [];
            $(this).find('td').each(function () {
                rowData.push($(this).text());
            });
            tableData.push(rowData);
        }
    });

    // Make an AJAX call to the server-side method
    $.ajax({
        type: "POST",
        url: "YourWebService.asmx/ExportGridViewToPdf",
        data: JSON.stringify({ gridData: tableData, columnNames: columns }),
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (response) {
            var fileName = "GridView.pdf";
            var blob = new Blob([response.d], { type: 'application/pdf' });
            var downloadLink = document.createElement("a");
            downloadLink.href = window.URL.createObjectURL(blob);
            downloadLink.download = fileName;
            document.body.appendChild(downloadLink);
            downloadLink.click();
            document.body.removeChild(downloadLink);
        },
        error: function (xhr, status, error) {
            console.error("Error exporting PDF: " + error);
        }
    });
}

This is the updated version of the cliend side (JS)

[WebMethod]
public byte[] ExportGridViewToPdf(string[][] gridData, string[] columnNames)
{
    try
    {
        // Create a new PDF document
        var document = new Document(PageSize.A4, 25, 25, 30, 30);
        var ms = new MemoryStream();
        var writer = PdfWriter.GetInstance(document, ms);
        document.Open();

        // Add the table to the PDF document
        var table = new PdfPTable(columnNames.Length);
        table.WidthPercentage = 100;

        // Add the column headers
        foreach (var columnName in columnNames)
        {
            var cell = new PdfPCell(new Phrase(columnName));
            cell.BackgroundColor = new BaseColor(System.Drawing.Color.LightGray);
            table.AddCell(cell);
        }

        // Add the data rows
        foreach (var row in gridData)
        {
            foreach (var value in row)
            {
                table.AddCell(value);
            }
        }

        document.Add(table);
        document.Close();
        writer.Close();

        return ms.ToArray();
    }
    catch (Exception ex)
    {
        // Handle the exception
        throw new Exception("Error exporting GridView to PDF: " + ex.Message);
    }
}

C# server side script (web method) - Updated.

Try this.