LinkLabel DataGrid Column

• Download source files - 1.91 Kb

Introduction

I needed to include a DataGrid column with a click-able cell. I found no valid solutions on the net (except some sold control packages and some tricks like mousedown and mousemove/hit-test on the grid) and I saw that many were asking for it... I decided to write it on my own. It's very simple and basic but it works very well.

This is what I needed and this is what I wrote, you may want to adapt it to your needs.

Missing you-may-need-them things (add them yourself)

• Font change on the grid.
  
• Right to left implementation.
• Visited links.
• Underline with no mouse on it (I needed the underline to appear when the mouse moves over the link text).
• Custom colorization for the link.

How it looks

How it works

The control overrides some DataGridColumnStyle methods (as you have to do when you write a custom ColumnStyle). When the control is initialized (in its constructor) a generic LinkLabel (this will be the main component that reacts to the clicks) is initialized with its standard size. When the TableStyle is bound to a DataGrid the control binds to some events.

• MouseMove - Used to show/hide the control when the user moves the cursor on the grid.
• DataSourceChanged - Used to hide the control (if visible) when the Datagrid.Datasource changes.
• BindingContextChanged - Used to hide the control (if visible) when the grid binding to data source changes.
• PositionChanged (DataBinding) - Used to hide the control (if visible) when the position of the binding in the datasource changes. (IE: you click the link and the DataGrid.Datasource is loaded with different data).

Overridden methods

• Editing: Abort, Commit, Edit
• Painting: Paint (with overloads)
• Cell size: GetMinimumHeight, GetPreferredHeight, GetPreferredSize
• Handling: SetDataGridInColumn, ConcedeFocus

How to use it

(Code used to take the pictures above)

Private Sub SetGridStyle()
    Dim grdStyle As New DataGridTableStyle

    'Other columns...

    Dim grdStileColEqv As New DataGridColumns.LinkLabel
    grdStileColEqv.MappingName = "Equivalenti"
    grdStileColEqv.HeaderText = "Eqv."
    grdStileColEqv.Alignment = HorizontalAlignment.Center
    grdStileColEqv.NullText = ""
    grdStileColEqv.Width = 40
    AddHandler grdStileColEqv.LinkClicked, AddressOf LinkClicked
    grdStyle.GridColumnStyles.Add(grdStileColEqv)

    grdLista.TableStyles.Add(grdListaStyle)
End Sub

Private Sub LinkClicked(ByVal sender As Object, _
            ByVal e As LinkLabelLinkClickedEventArgs)
    'Click handler code goes here.
    'if you need to access data of the row clicked
    '(for example to open a browser with the clicked url)
    'DirectCast(e.Link.LinkData, DataRowView)
    'contains the whole clicked row.
End Sub

Comments

I hope you'll find this code useful. If you want to contribute fixing bugs and/or adding functions, let me know. I'll modify the code accordingly.