How to hide a column (GridView) but still access its value?

小开

You can use DataKeys for retrieving the value of such fields, because (as you said) when you set a normal BoundField as visible false you cannot get their value.

In the .aspx file set the GridView property

DataKeyNames = "Outlook_ID"

Now, in an event handler you can access the value of this key like so:

grid.DataKeys[rowIndex]["Outlook_ID"]

This will give you the id at the specified rowindex of the grid.

小开

最佳答案

If I am not mistaken, GridView does not hold the values of BoundColumns that have the attribute visible="false". Two things you may do here, one (as explained in the answer from V4Vendetta) to use Datakeys. Or you can change your BoundColumn to a TemplateField. And in the ItemTemplate, add a control like Label, make its visibility false and give your value to that Label.

小开

If you do have a TemplateField inside the columns of your GridView and you have, say, a control named blah bound to it. Then place the outlook_id as a HiddenField there like this:

<asp:TemplateField HeaderText="OutlookID">
<ItemTemplate>
<asp:Label ID="blah" runat="server">Existing Control</asp:Label>
<asp:HiddenField ID="HiddenOutlookID" runat="server" Value='<%#Eval("Outlook_ID") %>'/>
</ItemTemplate>
</asp:TemplateField>

Now, grab the row in the event you want the outlook_id and then access the control.
For RowDataBound access it like:

string outlookid = ((HiddenField)e.Row.FindControl("HiddenOutlookID")).Value;

Do get back, if you have trouble accessing the clicked row. And don't forget to mention the event at which you would like to access that.

小开

Leave visible columns before filling the GridView. Fill the GridView and then hide the columns.

小开

You can do it programmatically:

grid0.Columns[0].Visible = true;
grid0.DataSource = dt;
grid0.DataBind();
grid0.Columns[0].Visible = false;

In this way you set the column to visible before databinding, so the column is generated. The you set the column to not visible, so it is not displayed.

小开

You can make the column hidden on the server side and for some reason this is different to doing it the aspx code. It can still be referenced as if it was visible. Just add this code to your OnDataBound event.

protected void gvSearchResults_DataBound(object sender, EventArgs e)
{
GridView gridView = (GridView)sender;


if (gridView.HeaderRow != null && gridView.HeaderRow.Cells.Count > 0)
{
gridView.HeaderRow.Cells[UserIdColumnIndex].Visible = false;
}


foreach (GridViewRow row in gvSearchResults.Rows)
{
row.Cells[UserIdColumnIndex].Visible = false;
}
}

小开

<head runat="server">
<title>Accessing GridView Hidden Column value </title>
<style type="text/css">
.hiddencol
{
display: none;
}
</style>


<asp:BoundField HeaderText="Email ID" DataField="EmailId" ItemStyle-CssClass="hiddencol" HeaderStyle-CssClass="hiddencol" >
</asp:BoundField>


ArrayList EmailList = new ArrayList();
foreach (GridViewRow itemrow in gvEmployeeDetails.Rows)
{
EmailList.Add(itemrow.Cells[YourIndex].Text);
}

小开

I used a method similar to user496892:

SPBoundField hiddenField = new SPBoundField();
hiddenField.HeaderText = "Header";
hiddenField.DataField = "DataFieldName";
grid.Columns.Add(hiddenField);


grid.DataSource = myDataSource;
grid.DataBind();


hiddenField.Visible = false;

小开

Define a style in css:

.hiddencol { display: none; }

Then add the ItemStyle-CssClass="hiddencol" and the HeaderStyle-CssClass="hiddencol" attribute to the grid field:

<asp:BoundField DataField="ID" HeaderText="ID" ItemStyle-CssClass="hiddencol"  HeaderStyle-CssClass="hiddencol" ClientIDMode="Static" />

小开

I have a new solution hide the column on client side using css or javascript or jquery.

.col0
{
display: none !important;
}

And in the aspx file where you add the column you should specify the CSS properties:

<asp:BoundField HeaderText="Address Key" DataField="Address_Id" ItemStyle-CssClass="col0" HeaderStyle-CssClass="col0" > </asp:BoundField>

小开

Here is how to get the value of a hidden column in a GridView that is set to Visible=False: add the data field in this case SpecialInstructions to the DataKeyNames property of the bound GridView , and access it this way.

txtSpcInst.Text = GridView2.DataKeys(GridView2.SelectedIndex).Values("SpecialInstructions")

That's it, it works every time very simple.

小开

You can do it code behind.

Set visible= false for columns after data binding . After that you can again do visibility "true" in row_selection function from grid view .It will work!!

小开

When I want access some value from GridView before GridView was appears.

I have a BoundField and bind DataField nomally.
In RowDataBound event, I do some process in that event.

Before GridView was appears I write this:

protected void GridviewLecturer_PreRender(object sender, EventArgs e)
{
GridviewLecturer.Columns[0].Visible = false;
}

小开

I searched a lot but no luck. The most of them was working with some errors. Finally I used this code and it worked for me. probably you should change 1 to some other value. for me I would hide second col.

protected void FoundedDrGridView_RowDataBound(object sender, GridViewRowEventArgs e) {

    if(e.Row.RowType!=DataControlRowType.Pager)e.Row.Cells[1].Visible = false;
}

小开

I just set the width to 0. and it works.

columns.AddFor(m => m.Id).Name("hide-id").Width(0);