Gridview update a column using another column - c#

I have a gridview bound with a database. I would like to add an extra column which has a linkbutton. The intention is that when clicked on the linkbutton, the user could toggle the value of a column which is bounded with the database.
I don't have any good ideas how to get started on this. Any help would be greatly appreciated!
Regards, Thijs

If I understand you question,
Make you gridview template fields. you can find more about Using TemplateFields in the GridView Control
Place the linkbutton with a commandname. See ButtonField.CommandName Property
In here do the same for the field you need to access. You will be able to access the values and change as you need.
Hope this helps

Right the way I would approach this is declare a class called GridRecord or something that represents a grid row.
class GridRecord
{
}
then in the class define all properties that will be the columns of your grid including the link column.
class GridRecord
{
private Image m_Link = [some image];
public GridRecord(){}
public Image Link
{
get { return m_Link; }
}
}
then in your grid code:
IList<GridRecord> records = new List<GridRecords>();
//Fill records object as you like.
Grid1.DataSource = records;
Then handle the RowCellClick or similar event and check if the clicked cell is of property type Link and use it.

Related

How to tell a GridViewRow to perform as a SEO-friendly link?

I have a GridView that has multiple columns. Let's say I have a business modell that looks like this:
public class MyObject
{
public String Title {get;set;}
public DateTime Date {get;set;}
public String NavigateUrl {get;set;}
}
My grid has two visible columns (Title and Date).
What I want to do, is to make each row clickable and to act like a link, that is going to the specified NavigateUrl.
No problem so far.
I could use the OnRowDataBound-Event to assign a Javascript that tells the Grid that I performed a Select and in the OnRowEvent, I could perform a Response.Redirect.
But that is not what I want to do, because it is not SEO friendly.
How can I make the whole "grid row as link" idea SEO friendly?
Edit: Adding an extra, visible column is no option
Provide a link as a column in the grid, and make the tr's onclick event fire off the link.
What you want is to make the GridView's cell contents LinkButtons, with the NavigateUrl specified. They will then show up as ordinary links on the page. You can define this behavior in the ASPX/ASCX markup and then DataBind, or dynamically build your GridView by adding rows manually in a loop through your data objects, setting the properties manually. Either one will work; I daresay databinding may be a bit faster but it can also be fiddly.

ASP.NET GridView Can't hide Columns

So I have an <asp:Gridview> and in my C# file, I am setting the datasource to some database table, and doing .DataBind().
However, I want to hide a column in the table based on a Boolean variable.
Something like this:
gridview.Columns['Field5'].Visible = false;
Or perhaps:
int c = gridview.Rows.Count();
for(int i = 0; i < c; i++){
gridview.Rows['Field5'].Remove();
}
Perhaps I cannot make it invisible, but I'm sure I can at least loop through and remove all rows related to the column "field5". I don't know how to go about doing this.
Does anyone perhaps have a proper link to using the GridView Class and how all the methods are suppose to be used because it's not clear, perhaps not written by microsoft?
Sorry if this is simplistic, the internet seems to lack a lot of C# documentation (or maybe it's just cluttered with too much useless ASP.net information).
No problem, the trick is that you have to reference the column by its index, not its name.
grid.Columns[1].Visible = false;
In your case you should loop through gridview and set cells you want to hide Visible=false
foreach (GridViewRow gvr in gv.Rows)
{
//here specify cell you want to hide
//also you may put any conditions
gvr.Cells[0].Visible = false; // Hide cell
}
To hide column you should go like that:
//here specify column you want to hide
grv.Columns[0].Visible = false; // Hide column
Also check this article http://www.codeproject.com/KB/webforms/Datagrid_Col_Example.aspx
I found a good method for doing something like that.
((DataControlField)gridView.Columns
.Cast<DataControlField>()
.Where(fld => (fld.HeaderText == "Title"))
.SingleOrDefault()).Visible = false;
I found it in below link
GridView Hide Column by code
The gridview is fine if you just want to quickly display some data, but don't need to modify it in any way. However if you do want to customize it, it is unpractical. It is easier and faster to build the table dynamically in your codebehind and you get all of the control you need.
Check out the first answer to this post: How to show pop up menu from database in gridview on each gridview row items?

Accessing properties of SelectedRow during SelectedIndexChanged event in dynamically generated GridView

I have an empty GridView object on a page that I bind to a LINQ qry result at run time. The GridView has a 'Select" button that fires the SelectedIndexChanged event and it's inside of this event that I'd like to access the data of one of the fields in the selected row.
So far, I can only find one way to do this, and it seems suboptimal:
protected void GridView2_SelectedIndexChanged(object sender, EventArgs e)
{
GridViewRow row = GridView2.SelectedRow;
string UserID = row.Cells[1].Text;
//Do stuff with the userID
}
So this just access the cell data directly based on the cell index. The UserID just happens to be in the second cell and so it works. But later down the road, the UserID may not be in that same column. It seems like I'd be better off looking up the value of this cell by accessing by the cell's header name, or by any method other than the cell index itself.
Any ideas?
Thanks!
Try this
User user = (User)((DataRowView)row.DataBoundItem).Row;
int userID = user.UserID;
I am assuming you have a class called User and you are binding the DataGridView to may a List
I don't know much about asp.net, but in the C# DataGridView you can index columns directly by column name, i.e.
string UserID = row.Cells["UserID"].Text;
or something like that. Might be worth a try.
You can use following code to retrieve object bound to current SelectedRow.
DataTable dt = (DataTable)<GridViewControl>.SelectedRow.DataItem
(here I have assumed that Grid is bound with DataTable.)

Gridview making a column invisable

Hi I have a grid view which is dynamically generated via C# using a DataSet.
I'm passing a row ID field (from the database) to the grid view, as this is required when a user clicks to edit a records. However I don't want the user to be able to view the column.
I have tried the following but it doesn’t seem to work? Could anyone suggest a way to hide the column or a better way of attaching the information to the grid view row so it can be used at a later stage.
c#
DataColumn ColImplantCustomerDetailsID = new DataColumn();
ColImplantCustomerDetailsID.ColumnName = "Implant ID";
ColImplantCustomerDetailsID.DataType = typeof(int);
ColImplantCustomerDetailsID.Visable = false; <-- visable doens't work here.
asp.net
DataColumn doesn't have a 'Visable' property. Heck, it doesn't have a 'Visible' property either.
Use this before you bind
gridviewNameHere.Columns[index].Visible = false;
You can make it visible again on one of your event handlers.
Another option, rather than hiding the column, is to use the DataKeyNames property of the GridView to store the name of the ID field. You can then use myGridView.SelectedValue to retrieve the selected ID.
Use the index of the column to hide it when you initialize it...
grid.Columns[index].Visible = false;
I actually hide a few things as you are suggesting, example - database status names for that row that can be used in code that the user does not need to see.
Accessing GridView Invisible Columns
http://www.highoncoding.com/Articles/178_Access_GridView_Invisible_Columns.aspx
In the OnRowDataBound event of the GridView component:
// c#
protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
int index = 0; // put the index of the column you need hide.
e.Row.Cells[index].Visible = false;
}

C# Add HyperLinkColumn to GridView

I'm trying to add HyperLinkColumns dynamically to my GridView. I have the following code:
HyperLinkColumn objHC = new HyperLinkColumn();
objHC.DataNavigateUrlField = "title";
objHC.DataTextField = "Link text";
objHC.DataNavigateUrlFormatString = "id, title";
objHC.DataTextFormatString = "{2}";
GridView1.Columns.Add(objHC);
This doesn't work, so.. how can i add a HyperLinkColumn to my GridView?
You might want to add it when the row is binded:
protected void yourGrid_RowDataBound(object sender, GridViewRowEventArgs e)
{
HyperLink hlControl = new HyperLink();
hlControl.Text = e.Row.Cells[2].Text; //Take back the text (let say you want it in cell of index 2)
hlControl.NavigateUrl = "http://www.stackoverflow.com";
e.Row.Cells[2].Controls.Add(hlControl);//index 2 for the example
}
You have to do it before the DataBinding takes place, check the GridView Events.
I think you should be using a HyperLinkField not a HyperLinkColumn.
In case, if you just want to redirect to another URL then simple use HyperLink web control and push it in the desired cell of GridView Row at RowDataBound event.
OR
If you want to perform any server event before sending it to another URL, try this
1) Add LinkButton object at RowDataBound event of GridView.
2) Set the CommandName, CommandArgument property, if requried to pass any data to this object.
3) Capture this event by handling the RowCommand event of the GridView.
By the way, I just think that you can use the DataGridView and in the Designer select the Link column and your problem would be over. The DataGridView does have a link column, than you just need to add an event on "Click" and you will be able to have what you want. This solution works if you can switch to DataGridView.
I know this thread is old but couldn't help adding my 2 cents. The procedure explained in the following tutorial worked perfectly for me:
ASP Alliance
It seems you have got things mixed up. I don't know - how that code compiles?
GridView's column collection can accept columns of type "DataControlField".
I think you need to initialize HyperLinkField and set relevant properties (text, NavigateUrl, HeaderText, Target) and add it to the columns collection.
HyperLinkColumn class is meaningful when you are using DataGrid (not in case of GridView).
Hope that helps.

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