在vb.net中使用通用列表对GridView进行排序

Question

I am doing custom sorting on a gridview that is being bound to a generic list.

My problem is the following:

    If direction.ToLower.Contains("desc") Then
        mygv.DataSource = myList.OrderByDescending(Function(w) w.Name)
        GridViewSortDirection = SortDirection.Descending
    Else
        mygv.DataSource = myList.OrderBy(Function(w) w.Name)
        GridViewSortDirection = SortDirection.Ascending 
    End If

    mygv.DataBind()

How can I replace the field w.Name with a parameter given to this function since it might be the name, city, country or any other field?

PS in C# using anonymous type it is easy but I am using vb.net here.

Thanks

Answer 1

Assuming you are trying to do this because you are using Linq to EF or Linq to SQL...

Import System.Linq.Expressions

Dim propertyName = "Name"
If direction.ToLower.Contains("desc") Then
    mygv.DataSource = myList.OrderByDescending(PropertyOf(Of Row)(propertyName))
    GridViewSortDirection = SortDirection.Descending
Else
    mygv.DataSource = myList.OrderBy(PropertyOf(Of Row)(propertyName))
    GridViewSortDirection = SortDirection.Ascending 
End If

mygv.DataBind()


Public Function PropertyOf(Of T)(string propertyName) as Expression(Of Func(Of T, object))
    Dim param = Expression.Parameter("x", typeOf T)
    Dim property = Expression.PropertyOrField(param, propertyName);
    Return Expression.Lambda(property, param)
End Function

Answer 2

Add this code in the following event of the gridview:

Protected Sub Gridview_Sorting(ByVal sender As Object, ByVal e As GridViewSortEventArgs) Handles Gridview.Sorting
    myList = myList.OrderBy(Function(x) x.GetType().GetProperty(e.SortExpression).GetValue(x)).ToList()
End Sub 

This should do the job.