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how to convert dataset to datatable in c# asp.net

i am trying to get files as bytes from table and show , i am getting the files as dataset but when trying to move it as datatable it shows row as zero and moves out of the if condition
protected void btnview_Click(object sender, EventArgs e)
{
string code = txtbudid.Text;
try
{
{
using (MasterManagement mMgmt = new MasterManagement(General.ConnString()))
{
dsBud = mMgmt.getfile(code);
DataTable dt = new DataTable();
dsBud.Tables.Add(dt);
if (dsBud != null)
{
if (dt.Rows.Count > 0)
{
byte[] bytes = (byte[])dt.Rows[0]["filedata"];
Response.Buffer = true;
Response.Charset = "";
Response.Cache.SetCacheability(HttpCacheability.NoCache);
//Response.ContentType = dt.Rows[]
Response.AddHeader("Content-disposition", "attachment;filename=" + dt.Rows[0]["filename"].ToString());
Response.BinaryWrite(bytes);
Response.Flush();
Response.End();
}
}
}
}

empty excel file when exporting to Gridview

hope you can help me.
I am developing a web page that produces a GridView in aspx which works and a button that when is clicked exports the gridview to excel file. This second case doesn't work for me, the file is empty. Here it is the code:
protected void Button2_Click(object sender, EventArgs e) //click en botón Exportar- -Click to export
{
try
{
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", "CUSS - Global Stats.xls"));
Response.ContentType = "application/ms-excel";
Response.ContentEncoding = System.Text.Encoding.Unicode;
System.IO.StringWriter writer = new StringWriter();
System.Web.UI.HtmlTextWriter html = new System.Web.UI.HtmlTextWriter(writer);
GridView1.AllowPaging = false;
GridView1.RenderControl(html); //gpp prints outs
Response.Write(writer.ToString());
Response.Flush();
Response.End();
}
catch (Exception)
{
}
Gridview is properly produce in asp as shown in pic.GridViewResult
protected void Button1_Click(object sender, EventArgs e)
{
...
GridView1.DataSource = Prints.ToList();
GridView1.DataBind();
...
}
Can you pls help me?

There should be a better way to do it, but I 'make' my gridview again:
using ClosedXML.Excel;
Click event:
public void button1_Click(object sender, EventArgs e)
{
using(XLWorkbook libro_trabajo = new XLWorkbook())
{
DataSet ps = datos_referencias();
libro_trabajo.Worksheets.Add(ps);
libro_trabajo.Style.Alignment.Horizontal = XLAlignmentHorizontalValues.Center;
libro_trabajo.Style.Font.Bold = true;
Response.Clear();
Response.Buffer = true;
Response.Charset = "";
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("content-disposition", "attachment;filename=reporte_clientes.xlsx");
using (MemoryStream memoria = new MemoryStream())
{
libro_trabajo.SaveAs(memoria);
memoria.WriteTo(Response.OutputStream);
Response.Flush();
Response.End();
}
}
}
Getting my data set:
public DataSet datos_referencias()
{
DataSet ds = new DataSet();
DataTable tabla_detallado = new DataTable("Clientes");
tabla_detallado.Columns.Add(new DataColumn("Cliente", typeof(string)));
objeto = new Conexion();
try
{
objeto.abrir_conexion_mysql();
objeto.cadena_comando_mysql = "SELECT * from ...ETC ";
objeto.aplicar_comando_mysql_extraccion();
while (objeto.leer_comando.Read())
{
DataRow fila = tabla_detallado.NewRow();
fila["Cliente"] = (objeto.leer_comando.GetString(1)).ToUpper();
tabla_detallado.Rows.Add(fila);
}
}
finally {objeto.cerrar_conexion_mysql_extraccion(); }
ds.Tables.Add(tabla_detallado);
return ds;
}

Maybe because of make response GZip ?
On filter ?
response.Filter = New GZipStream(response.Filter, CompressionMode.Compress)

How to Export multiple header Gridview Data to Excel

I have a gridview which has multiple headers added during run time as shown in snap below:
I want to export the data from this gridview to excel for which I have the following code:
protected void Button1_Click(object sender, EventArgs e)
{
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.xls");
Response.Charset = "";
Response.ContentType = "application/vnd.ms-excel";
using (StringWriter sw = new StringWriter())
{
HtmlTextWriter hw = new HtmlTextWriter(sw);
gdView.HeaderRow.BackColor = Color.White;
foreach (TableCell hcell in gdView.HeaderRow.Cells)
{
hcell.BackColor = Color.White;
}
foreach (GridViewRow row in gdView.Rows)
{
{
row.BackColor = Color.White;
foreach (TableCell cell in row.Cells)
{
cell.CssClass = "textmode";
}
}
}
gdView.RenderControl(hw);
//style to format numbers to string
string style = #"<style> .textmode { } </style>";
Response.Write(style);
Response.Output.Write(sw.ToString());
Response.Flush();
Response.End();
}
}
public override void VerifyRenderingInServerForm(System.Web.UI.Control control)
{
// controller
}
The excel output I am getting is as follows:
As you can see the color of the header rows is continuing beyond the table area. Also the top header rows are collapsed in the excel output.
Request you all to kindly suggest how this can be resolved.
Thanks.

I could finally solve the issue by modifying the code as below:
protected void Button1_Click(object sender, EventArgs e)
{
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.xls");
Response.Charset = "";
Response.ContentType = "application/vnd.ms-excel";
using (StringWriter sw = new StringWriter())
{
HtmlTextWriter hw = new HtmlTextWriter(sw);
for (int x = 0; x <= 3; x++)
{
GridViewRow rows = (GridViewRow)gdView.HeaderRow.Parent.Controls[x];
rows.BackColor = Color.White;
rows.Height = 15;
for (int i = 0; i <= rows.Cells.Count - 1; i++)
{
rows.Cells[i].BackColor = Color.Maroon;
}
}
foreach (GridViewRow row in gdView.Rows)
{
row.BackColor = Color.White;
foreach (TableCell cell in row.Cells)
{
cell.VerticalAlign = VerticalAlign.Middle;
cell.CssClass = "textmode";
}
}
gdView.RenderControl(hw);
//style to format numbers to string
string style = #"<style> .textmode { } </style>";
Response.Write(style);
Response.Output.Write(sw.ToString());
Response.Flush();
Response.End();
}
}
public override void VerifyRenderingInServerForm(System.Web.UI.Control control)
{
// controller
}

nested gridview export to excel, asp.net c#

I want to export the parent grid view and nested gridview to an excel.
I have a code that only work to export a normal simple gridview.
Tried to debug the code, found there is no error or whatsoever.
It is just after i click the export button, it doesnt export to excel.
here is my code
protected void asd()
{
string title = "";
string attempt = "SELECT * FROM Poll Where PollID = '" + Session["abc"] + "'";
cmd = new SqlCommand(attempt, con);
dr = cmd.ExecuteReader();
while (dr.Read())
{
title = dr["PollTitle"].ToString();
}
string filename = String.Format(title + " RESULTS. " + "{0}_{1}.xls",
DateTime.Today.Month.ToString(), DateTime.Today.Year.ToString());
Response.Clear();
Response.AddHeader("Content-Disposition", "attachment;filename=" + filename);
Response.Charset = "";
// SetCacheability doesn't seem to make a difference (see update)
Response.Cache.SetCacheability(System.Web.HttpCacheability.NoCache);
Response.ContentType = "application/vnd.xls";
System.IO.StringWriter stringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter htmlWriter = new HtmlTextWriter(stringWriter);
// Replace all gridview controls with literals
ClearControls(GridView3);
// Throws exception: Control 'ComputerGrid' of type 'GridView'
// must be placed inside a form tag with runat=server.
// ComputerGrid.RenderControl(htmlWrite);
// Alternate to ComputerGrid.RenderControl above
System.Web.UI.HtmlControls.HtmlForm form
= new System.Web.UI.HtmlControls.HtmlForm();
Controls.Add(form);
form.Controls.Add(GridView3);
form.RenderControl(htmlWriter);
Response.Write(stringWriter.ToString());
Response.End();
}
private void ClearControls(Control control)
{
for (int i = control.Controls.Count - 1; i >= 0; i--)
{
ClearControls(control.Controls[i]);
}
if (!(control is TableCell))
{
if (control.GetType().GetProperty("SelectedItem") != null)
{
LiteralControl literal = new LiteralControl();
control.Parent.Controls.Add(literal);
try
{
literal.Text =
(string)control.GetType().GetProperty("SelectedItem").
GetValue(control, null);
}
catch
{ }
control.Parent.Controls.Remove(control);
}
else if (control.GetType().GetProperty("Text") != null)
{
LiteralControl literal = new LiteralControl();
control.Parent.Controls.Add(literal);
literal.Text =
(string)control.GetType().GetProperty("Text").
GetValue(control, null);
control.Parent.Controls.Remove(control);
}
}
return;
}
protected void Export_buttonClick(object sender, EventArgs e)
{
asd();
}
this code is working for a normal gridview, but not the one with nested gridview.

I've experienced the 'must be placed inside a form tag with runat=server' error in the past and resolved the issue by adding the following override method in my page codebehind:
public override void VerifyRenderingInServerForm(Control control) {}
More info on MSDN.
For reference, I also used this code for exporting my GridViews:
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment;filename=your_file.xls");
Response.Charset = "";
Response.ContentEncoding = System.Text.Encoding.Default;
Response.ContentType = "application/ms-excel";
StringWriter sw = new StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(sw);
your_GridView.RenderControl(hw);
Response.Output.Write(sw.ToString());
Response.Flush();
Response.End();

how to export a grid view in to excel?

hi i am developing an application where i am using a grid to dispaly data and adding a dynamic datatable as the header of the gridview and iam using the following code to export the grid view into excel but i am unable get the datatable which was added dynamically to the grid into the excel. the code i am using is:
Response.AddHeader("content-disposition", "attachment;filename=Report.xls");
Response.Charset = String.Empty;
Response.ContentType = "application/vnd.xls";
System.IO.StringWriter sw = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter hw = new HtmlTextWriter(sw);
GridView1.DataBind();
GridView1.RenderControl(hw);
Response.Write(sw.ToString());
Response.End();
is thee any other method to follow.
Thanks in advance!

I don't see where you are adding the dynamic datatable as the header?? This should come after the databind and before the GridView1.RenderControl(hw);

try this one in the button click event
protected void btnExcel_Click(object sender, ImageClickEventArgs e)
{
Response.ClearContent();
Response.Buffer = true;
Response.AddHeader("content-disposition", string.Format("attachment; filename= {0}", "Customers.xls"));
Response.ContentType = "application/ms-excel";
StringWriter sw = new StringWriter();
HtmlTextWriter htw = new HtmlTextWriter(sw);
gvdetails.AllowPaging = false;
gvdetails.DataBind();
//Change the Header Row back to white color
gvdetails.HeaderRow.Style.Add("background-color", "#FFFFFF");
//Applying stlye to gridview header cells
for (int i = 0; i < gvdetails.HeaderRow.Cells.Count; i++)
{
gvdetails.HeaderRow.Cells[i].Style.Add("background-color", "#507CD1");
}
int j = 1;
//This loop is used to apply stlye to cells based on particular row
foreach (GridViewRow gvrow in gvdetails.Rows)
{
gvrow.BackColor = Color.White;
if (j <= gvdetails.Rows.Count)
{
if (j % 2 != 0)
{
for (int k = 0; k < gvrow.Cells.Count; k++)
{
gvrow.Cells[k].Style.Add("background-color", "#EFF3FB");
}
}
}
j++;
}
gvdetails.RenderControl(htw);
Response.Write(sw.ToString());
Response.End();
}

this will export gridview in formatted output file
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment; filename=gridSample.xls");
Response.Charset = "";
Response.ContentType = "application/vnd.ms-excel";
using (StringWriter sw = new StringWriter())
{
HtmlTextWriter hw = new HtmlTextWriter(sw);
//to export all pages
gridSample.AllowPaging = false;
gridSample.DataSource = progress.getSample();
gridSample.DataBind();
//bind again
gridSample.HeaderRow.BackColor = Color.White;
foreach (TableCell cell in gridSample.HeaderRow.Cells)
{
cell.BackColor = gridSample.HeaderStyle.BackColor;
}
foreach (GridViewRow row in gridSample.Rows)
{
row.BackColor = Color.White;
foreach (TableCell cell in row.Cells)
{
if (row.RowIndex % 2 == 0)
{
cell.BackColor = gridSample.AlternatingRowStyle.BackColor;
}
else
{
cell.BackColor = gridSample.RowStyle.BackColor;
}
cell.CssClass = "textmode";
}
}
gridSample.RenderControl(hw);
//style to format numbers to string
string style = #"<style> .textmode { } </style>";
Response.Write(style);
Response.Output.Write(sw.ToString());
Response.Flush();
Response.End();
}