Silverlight DataGrid with Dynamic Multiple Row Columns in Header

• Download source code - 158 KB

Introduction

I was developing a product in 2006 and one of the requirements was to create a DataGrid with multiple columns and rows in the header. In my previous article Dynamic Multiple Row Column Grid Header, I have presented the idea I have used. The last few months, I was exploring Silverlight and I was wondering how the same can be achieved using the Silverlight DataGrid. I searched the internet looking for a solution, but couldn't find any. So I came up with a very crude way to do this. I am looking for a better solution. Also, another feature I wanted was to export the same in Excel. At this point, I don't know how to do that.

Background

So the goal of this experiment is to achieve the following output using the Silverlight DataGrid:

I have used a similar technique described in my previous article to calculate the row and column spans of the headers. I am skipping the logic here. This time, I also need a footer. So the approach I have taken is that I will create a Grid of MxN size dynamically. M will be the number of header rows, plus 1 for the DataGrid, plus 1 for the footer. I.e., M = number of header rows + 2. N will be equal to the number of DataGrid columns. I will put the footer details in the last row of the grid, the DataGrid in the last but first row of the grid, and all the header items in the remaining rows with the appropriate row and col span.

Using the code

I have used the same three classes (described in the previous article) to parse the header string and create the collection to render.

• DynamicHeaderCell
• DynamicHeader
• DynamicHeaders

I have added another class RowHeader, and instead of an ArrayList, I have used a list of RowHeaders to get the collection of header cells after parsing. I have added another class SalseData to get the necessary data. This class has four static methods:

• GetSalseData - Data to display in the DataGrid
• GetSalseDataHeader - The header string
• GetSalseDataColumnHeader - To create the DataGrid columns
• GetSalseDataFooter - Data to display in the footer

Hard coded strings are used in the above functions. In the real application, the methods can get the data from the database or any other source.

The XAML code is simple as generated by Visual Studio. All the work is done dynamically in the code-behind.

The following member variables are defined in the code-behind:

DataGrid grdData = new DataGrid() { AutoGenerateColumns = false };
bool bGridInitialized = false;
List<RowHeader> Headers = null;

Three methods are defined in the code-behind:

• InitUI
• grdData_LayoutUpdated
• AddHeaderTextBlock

In the method InitUI():

1. The header is parsed and stored in the Headers collection:

String[] ColHeaders = SalseData.GetSalseDataColumnHeader().Split(',');
Headers = dynHead.ParseHeader();

2. The DataGrid columns are created and the data source added:

foreach (String col in ColHeaders)
{
    String[] colHeader = col.Split('|');
    grdData.Columns.Add(new DataGridTextColumn { Header = colHeader[0], 
    Binding = new System.Windows.Data.Binding(colHeader[1]), 
    IsReadOnly = true });
}
grdData.ItemsSource = SalseData.GetSalseData();

3. The grid rows are created.

In the method grdData_LayoutUpdated():

1. The grid columns are created:

for (int i = 0; i < grdData.Columns.Count; i++)
{
    DataGridColumn dgc = grdData.Columns[i];
    LayoutRoot.ColumnDefinitions.Add(...);
}

2. The AddHeaderTextBlock method is called to add the header and the footer text.
3. The DataGrid is positioned.

In the method AddHeaderTextBlock():

1. A border with proper border thickness and a text block with a header text are added to the appropriate cell of the grid.

History

• Initial version.