RadGrid for ASP .NET version
RadControls for ASP .NET AJAX version |
Q3 2006 and later
2008.1.415 and lat
|
| .NET version |
2.0 and later
|
| Visual Studio version |
2005 and later
|
| Programming language |
C#
|
| Browser support |
all supported by RadGrid for ASP .NET
all browsers supported by RadControls for ASP .NET AJAX
|
PROJECT DESCRIPTION
r.a.d.grid does not require the page developer to recreate all dynamically created columns on post back. It knows what columns were added and automatically recreates them. The only limitation is that RadGrid will do that for the built-in columns only. Creating custom columns will require you to handle the ColumnCreating event and recreate your column there.
The problem with generic column classes lies in the fact that the event arguments will contain the short type name without the generic parameter. There is no way to get the full
GenericColumn<Filter> type name and you will only get a
GenericColumn`1 string.
Working around that limitation will require that you store each generic parameter type in the page view state. The easiest approach is to use an ordered collection such as an ArrayList:
| ArrayList types = new ArrayList(); |
| ViewState["columnTypes"] = types; |
| |
| GenericColumn<Filter> myColumn = new GenericColumn<Filter>(); |
| RadGrid1.Columns.Add(myColumn); |
| myColumn.DataField = "CustomerID"; |
| myColumn.UniqueName = "CustomerID"; |
| myColumn.DataType = typeof(string); |
| types.Add(myColumn.GetType().GetGenericArguments()[0].AssemblyQualifiedName); |
| |
Recreating controls on post back will involve looking up the parameter type, creating a specific instance of the generic type, and creating an instance of that type as the grid column:
| int columnIndex = 0; |
| protected void RadGrid1_ColumnCreating(object sender, Telerik.WebControls.GridColumnCreatingEventArgs e) |
| { |
| ArrayList types = (ArrayList) ViewState["columnTypes"]; |
| Type paramType = Type.GetType((string)types[columnIndex]); |
| Type columnType = typeof(GenericColumn<>).MakeGenericType(paramType); |
| |
| GridColumn myColumn = (GridColumn)Activator.CreateInstance(columnType); |
| e.Column = myColumn; |
| |
| myColumn.UniqueName = "test1"; |
| |
| columnIndex++; |
| |
| } |
| |