SharePoint Fun

Let’s say you have 2 RadGrids defined in your aspx page. Both grids happen to share the same ItemDataBound event, but you’d like to apply a small tweak depending on what grid is calling the ItemDataBound method.

In order to implement your tweak, you’ll need a way to find the ID of the grid that made the call. And not the ASP.NET generated ID, since that can be rather ugly, but the ID of the control you created in the aspx page. The following example demonstrates how this can be achieved:

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<radG:RadGrid ID="rgThisYearsItems" runat="server" OnItemDataBound="rgItems_ItemDataBound"></radG:RadGrid>
 
<radG:RadGrid ID="rgLastYearsItems" runat="server" OnItemDataBound="rgItems_ItemDataBound"></radG:RadGrid>

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protected void rgItems_ItemDataBound(object sender, GridItemEventArgs e)
{
        // we need to determine what grid is calling the itemdatabound event
        RadGrid grid = (RadGrid)e.Item.OwnerTableView.OwnerGrid;
 
        if (grid.ID == "rgThisYearsItems")
        {
            // perform some logic here
        }
 
        if (grid.ID == "rgLastYearsItems")
        {
            // perform some logic here
        }
}

The reason you might want to implement the above is for code reuse. If you’ve got two grids and the ItemDataBound event for both will be really similar minus a line or two, you can have them both call the same ItemDataBound event and use the above logic to determine when to run the custom pieces.

Thoughts?

So here’s the idea. I’ve got a RadGrid on my page that is populated programmatically. I build a DataTable from various different sources and once I’m satisifed with how my DataTable looks, I set the grid’s DataSource property and bind.

That’s all good, except now I want to insert a header row in the middle of my grid. The idea behind this row is to simply provide a clear segregation between my different sources of data. It’s all one grid remember, but I wanted a way to distinguish between the data.

I came up with the idea to simply add a header row at the point I needed, set the ColumnSpan to match the number of columns I have in my grid, set the HorizontalSpan to center the text and finally set the Visibility on all other columns to false.

Here is what I ended up with. The grid is setup with 5 columns: Name, Address, City, Province and Country. At the point where I’d like my see my header row in the grid, I set the Name column to the text I’d like the header to contain. Keep in mind that I have rows being added before and after the code sample below. I’ve inserted the code exactly where I want my header to appear:

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DataRow row = dt.NewRow();
row["Name"] = "My heading that I'd like to show";
dt.Rows.Add(row);

Now in the ItemDataBound event, I can modify this particular row that I just created so that it spans all the columns and is centered as follows:

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protected void RadGrid1_ItemDataBound(object sender, GridItemEventArgs e)
{
    if (e.Item is GridDataItem) 
    {
        GridDataItem dataItem = e.Item as GridDataItem;
 
        // i use the second index to get at the name column. the first two indexes
        // are empty for me and don't contain any valuable data
        if (dataItem.Cells[2].Text == "My heading that I'd like to show")
        {
            dataItem["Name"].ColumnSpan = 8;
            dataItem["Name"].HorizontalAlign = HorizontalAlign.Center;
 
            dataItem["Name"].BackColor = System.Drawing.Color.Black;
            dataItem["Name"].ForeColor = System.Drawing.Color.White;
 
            dataItem["Address"].Visible = false;
            dataItem["City"].Visible = false;
            dataItem["Province"].Visible = false;
            dataItem["Country"].Visible = false;
       }
    }
}

That’s what I came up with and it seems to work great. If anyone has a better technique for implementing this, please let me know.

In this post, I’m going to talk a little bit about how to access specific controls within a RadGrid while that grid is in edit mode. There are several reasons you may want to do this:

• You might need to set some defaults for the control.
• You want to perform some calculation and output some default value to the control.
• You may need to change the attributes of a control (color, font etc).

In order to achieve any of the above, we need a way to get access to the controls while in edit mode.

To begin, you’ll need to add the ItemDataBound event to your grid, so that when we’re in edit mode and the items are being bound, we can perform our custom code.

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OnItemDataBound="RadGrid1_ItemDataBound"

Next, add the method to handle the ItemDataBound event for the grid as follows:

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protected void RadGrid1_ItemDataBound(object sender, GridItemEventArgs e)
{
    if ((e.Item is GridEditableItem) && (e.Item.IsInEditMode))
    {
        GridEditableItem edititem = (GridEditableItem)e.Item;
        TextBox txtbx = (TextBox)edititem["ColumnUniqueName"].Controls[0];
        txtbx.Text = "";
    }
}

The above code is pretty straight forward. We check first to see if we’re in edit mode, because we don’t want to be performing this code during any other time. We create a GridEditableItem object so that we can talk to the controls of the item we’re currently editing. And finally, if it’s a textbox we’re dealing with, create a TextBox object and using the unique name you’ve assigned that column, we can access the control within it.

Now that you have a TextBox object, you can access all the properties and methods of that object as you normally would.

If the control in question is a checkbox, it’s not much different:

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CheckBox cb = (CheckBox)edititem["ColumnUniqueName"].Controls[0];
 
if (cb.Checked) {
    // perform some custom code
}

The solution for this was not totally obvious to me when reading the RadGrid documentation, so I did a bit of forum searching and found the solution below:

Let’s say you’ve got a RadGrid on your page, and you’ve configured it already to allow for filtering by setting the AllowFilteringByColumn property to true as follows:

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 <radG:RadGrid ID="rgDistricts" runat="server" PageSize="5" Skin="Default" AllowFilteringByColumn="true" AllowPaging="True" AllowSorting="True" GridLines="None" AutoGenerateColumns="False" OnDeleteCommand="DistrictDelete" OnItemCommand="ItemClick" OnNeedDataSource="District_NeedDataSource">

The code above will insert filter boxes and a filter menu into your grid which will allow users to enter a value and select a filter funtion to filter the grid. This works good except it requires that a user enter a value and then use the mouse to select how they want to filter on that value before the grid is affected.

It would be faster and a better user experience to allow users to enter a value and then hit the enter key and then have the grid filter. So to achieve this, you have to tell each of your bound columns that a. you want to auto post back on filter and b. what default filter funtion to use as follows:

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<radG:GridBoundColumn DataField="Address" SortExpression="Address" HeaderText="Address" UniqueName="Address" AutoPostBackOnFilter="true" CurrentFilterFunction="Contains"> </radG:GridBoundColumn>

Let’s say you have an employee table and you want to be able to create a hyperlink on the employee name column with a custom url in the form of: “employee.aspx?ID=”

Within an asp.net datagrid, you could achieve this by creating a hyperlinkcolumn and specifying the DataNavigateUrlField and the DataNavigateUrlFormatString as follows:

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<asp:HyperLinkColumn DataNavigateUrlField="EmployeeID" DataNavigateUrlFormatString="employee.aspx?ID={0}" DataTextField="Name"></asp:HyperLinkColumn>

If you’re using a Telerik TreeView control, however, the syntax is slightly different. While you can specify DataBindings within a Telerik TreeView control, there doesn’t seem to be a NavigateUrlFormatString property available. You can set the NavigateUrl and the NavigateUrlField property, but that’s not enough to get the same results as above.

The best way to accomplish this is:

Within the RadTreeView control, add an OnNodeBound event as follows. This will enable us to set our NavigateUrl at the same time our nodes are being bound to the treeview thus giving us more control:

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<radT:RadTreeView ID="rtvEmployees" Skin="Default" runat="server" OnNodeBound="Node_Bound"></radT:RadTreeView>

Within your code behind file, create a function as follows:

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protected void Node_Bound(object sender, Telerik.WebControls.RadTreeNodeEventArgs e)
{
    e.NodeBound.NavigateUrl = "employee.aspx?ID=" + e.NodeBound.Value;
}

Don’t forget that whether you build the structure programmatically or inline, you’ll need to specify the DataFieldID, the DataFieldParentID, the DataTextField and the DataValueField. In my case, I did it programmatically as follows:

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rtvUserGroups.DataSource = dsTreeView;
 
rtvUserGroups.DataFieldID = "EmployeeID";
 
rtvUserGroups.DataFieldParentID = "ParentID";
 
rtvUserGroups.DataValueField = "EmployeeID";
 
rtvUserGroups.DataTextField = "Name";
 
rtvUserGroups.DataBind();