"autogenerate" columns in multi column combobox

[Christian]

I'm using a autocompleting and multicolumns radcombo box to produce an application.

Up to now I've hard coded the itemtemplate in the aspx page bt now I'm trying to roll it out a bit more dynamically.

Part of the application allows users to choose which database fields to include in the query so I won't know what to add to the <itemtemplate> until run time.

What is the best way to dynamically "autogenerate" the columns in the multicolumn combo??

[Kalina]

Hi Christian,

Please take a look at the "Dynamic Multi-Column Template" Code Library.

Greetings,
Kalina
the Telerik team

[Christian]

thank you , its  step in the right direction but doesn't entirely solve my problem....

I have an application which allows users to choose which columns are included in a SQL statement, so the resulting multicolumn could have 3 or 13 columns in it, with no set column name.  The code you kindly suggested requires that the columns be "pre-built" in the "InstatiateIn" function.

[Kalina]

Hi Christian,

The scenario that you are trying to implement is quite unusual – I started researching the issue but this will take some more time. I will contact you when I find something of interest.

Best wishes,
Kalina
the Telerik team

[Christian]

Well, I've achieved some success.  I am now able to create a dynamic multicolumn dropdown with dynamic column count.

in the main asp.cs file:

DataTable dt = GetData(e.Text);
//use my SQL to create a datatable
int colCount = dt.Columns.Count;
//count how many columns are in the table and pass this out to the templates to create the correct number of coulmns
RadComboBoxProduct.HeaderTemplate = new MultiColumnHeaderTemplate(colCount);
RadComboBoxProduct.ItemTemplate = new MultiColumnItemTemplate(colCount);

RadComboBoxProduct.DataSource = dt;
RadComboBoxProduct.DataTextField = "idCode";
//I've slightly cheated here because the first column in my SQL will ALWAYS be this column entitled idCode
RadComboBoxProduct.DataBind();

In the itemTemplate.cs file:

    


public int colCount;
    public int counter = 0;
    public MultiColumnItemTemplate(int i)
    {
        colCount = i;
    }
    public void InstantiateIn(Control container)
    {
        decimal split = 100 / colCount;
        int splitInt = Convert.ToInt32(Math.Round(split));
//because individual radcomboboxitems are dealt with as seperate tables, it doesn't always keep the columns straight
//the code gets around this by dividing the space equally between the number of columns.  turning on wrap makes this work. It does however break if too many columns are displayed, causing the columns to be too thin for the longest string in the columns
        Table tb;
        TableRow tr;
        tb = new Table();
        tb.Width = Unit.Percentage(100);
        tr = new TableRow();
        for (int i = 0; i < colCount; i++)
        {
            TableCell tc;
            tc = new TableCell();
            tc.Width = Unit.Percentage(splitInt);
            tc.DataBinding += new EventHandler(tdCell_DataBinding);
            tc.Wrap = true;
            tr.Cells.Add(tc);
        }
        tb.Rows.Add(tr);
        container.Controls.Add(tb);
    }

All of the columns are given the same datbinding function:

void tdCell_DataBinding(object sender, EventArgs e)
    {
        TableCell tc = (TableCell)sender;
        RadComboBoxItem item = (RadComboBoxItem)tc.BindingContainer;
        DataRowView row = (DataRowView)item.DataItem;
        tc.Text = row[counter].ToString();
//using previous code to determine how many coumns my sql requires
//this loops through the rows being passed to put the contents of each row
        if (counter < colCount-1)
        {
            counter ++;
        }
        else
        {
            counter=0;
        }
    }

so right now this is mostly working except:

I currently can't get the headertemplate to display column names

bit of a hack on the table columns, I think getting the headertemplate working would sort this and create proper columns


its still a work in progress!! thanks for your assistance thus far.

CB

[Kalina]

Hi Christian,

As I understand, you have created two custom templates: MulticolumnItemTemplate and MulticolumnHeaderTemplate.
However at the code snippets provided I can see only the code of MulticolumnItemTemplate.
Could you please paste here the implementation of MultiColumnHeaderTemplate?
Thank you in advance.

All the best,
Kalina
the Telerik team