Grouping column with ListSortDirection None

[FMorales]

 Hi I need to apply "None" as ListSortDirection on a Grouping column programmatically but only "Ascending" and "Descending" values are possible.

GroupDescriptor groupByTemperature = new GroupDescriptor();
groupByTemperature.GroupNames.Add("Temperature", ListSortDirection.Ascending);

Any idea of how perform this action?

Francisco

[Dess | Tech Support Engineer, Principal]

Hello Francisco,

Thank you for writing.

The GroupDescriptor.GroupNames property defines the property, by which the data will be grouped. The GroupName is a SortDescriptorCollection and defines group names for one grouping criteria. Note that System.ComponentModel.ListSortDirection enumeration specifies the direction of a sort operation. It has only two values: Ascending and Descending.

However, to change the order of your Groups, you must implement your own generic group comparer and change the default one. Here is a simple example:

private void Form1_Load(object sender, EventArgs e)
{
    this.customersTableAdapter.Fill(this.nwindDataSet.Customers);
    this.radGridView1.MasterTemplate.GroupComparer = new GroupComparer();

    GroupDescriptor descriptor = new GroupDescriptor();
    descriptor.GroupNames.Add("Country", ListSortDirection.Ascending);
    this.radGridView1.GroupDescriptors.Add(descriptor);
}

public class GroupComparer : IComparer<Group<GridViewRowInfo>>
{
    public int Compare(Group<GridViewRowInfo> x, Group<GridViewRowInfo> y)
    {
        return x.Key.GetHashCode().CompareTo(y.Key.GetHashCode());
    }
}

I hope this information helps. Should you have further questions, I would be glad to help.

 

Regards,
Dess
Telerik

 

 

[FMorales]

Hi Dess,

thanks you very much for your reply.

i am trying to  create a groupComparer for more than one level but I can not get it works, could you provide a simple example of a Compare method for more than one level??, I notice that x and y has a property level but I do not understand how make a sorting correctly.

I am trying for example to create 2 groups, one for Temperature and another one for Voltage, both with int value.

Thanks a lot

Francisco

[Dess | Tech Support Engineer, Principal]

Hello Francisco,

Thank you for writing back.

The GroupComparer is set globally to the MasterTemplate. Its Compare method will be called every time when two groups need to be compared. The Level property just indicates to what level the specific group belongs. Hence, when you add one group, you perform the desired groups ordering for that level. Afterwards, when you add another group, the Compare method will be called again for all group levels. Note that you have access to the specific GroupDescriptor and you can determine over what property/column you are going to group and perform the desired order. 

Here is a sample code snippet demonstrating how to sort the groups for column "B" by considering the numeric value and order the groups in column "C" in a reversed string order:

public Form1()
{
    InitializeComponent();

    DataTable dt = new DataTable();
    dt.Columns.Add("A", typeof(string));
    dt.Columns.Add("B", typeof(string));
    dt.Columns.Add("C", typeof(string));

    dt.Rows.Add("DataA.1", "1", "DataC.4");
    dt.Rows.Add("DataA.2", "5", "DataC.42");
    dt.Rows.Add("DataA.3", "10", "DataC.43");
    dt.Rows.Add("DataA.4", "11", "DataC.14");
    dt.Rows.Add("DataA.5", "20", "DataC.54");
    dt.Rows.Add("DataA.6", "2", "DataC.6");
    dt.Rows.Add("DataA.7", "3", "DataC.17");

    dt.Rows.Add("DataA.1", "1", "DataC.1");
    dt.Rows.Add("DataA.2", "5", "DataC.2");
    dt.Rows.Add("DataA.3", "10", "DataC.3");
    dt.Rows.Add("DataA.4", "11", "DataC.4");
    dt.Rows.Add("DataA.5", "20", "DataC.5");
    dt.Rows.Add("DataA.6", "2", "DataC.6");
    dt.Rows.Add("DataA.7", "3", "DataC.7");

    this.radGridView1.DataSource = dt;
    this.radGridView1.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;
    this.radGridView1.MasterTemplate.GroupComparer = new GroupComparer();
}

public class GroupComparer : IComparer<Group<GridViewRowInfo>>
{
    public int Compare(Group<GridViewRowInfo> x, Group<GridViewRowInfo> y)
    {
        DataGroup group = x as DataGroup;

        if (group == null)
        {
            group = y as DataGroup;
        }

        string propertyName = group.GroupDescriptor.GroupNames.First().PropertyName;
        if (propertyName == "B")
        {
            int parsedX;
            int parsedY;
            if (int.TryParse(((object[])x.Key).First().ToString(), out parsedX) &&
                int.TryParse(((object[])y.Key).First().ToString(), out parsedY))
            {
                if (group.GroupDescriptor.GroupNames.First().Direction == ListSortDirection.Ascending)
                {
                    return parsedX.CompareTo(parsedY);
                }
                else
                {
                    return (-1) * parsedX.CompareTo(parsedY);
                }
            }
        }
        else if (propertyName == "C")
        {
            if (group.GroupDescriptor.GroupNames.First().Direction == ListSortDirection.Ascending)
            {
                return (-1) * ((object[])x.Key).First().ToString().CompareTo(((object[])y.Key).First().ToString());
            }
            else
            {
                return ((object[])x.Key).First().ToString().CompareTo(((object[])y.Key).First().ToString());
            }
        }

        return x.Key.ToString().CompareTo(y.Key.ToString());
    }
}

I hope this information helps. If you have any additional questions, please let me know.

Regards,
Dess
Telerik