I'm trying to create a DataGridTableStyle object so that I can control the column widths of a DataGrid. I've created a BindingSource object bound to a List. Actually it's bound to an anonymous type list created though Linq in the following manner (variable names changed for clarity of what I'm doing):
List<myType> myList = new List<myType>(someCapacity);
.
...populate the list with query from database...
.
var query = from i in myList
select new
{
i.FieldA,
i.FieldB,
i.FieldC
};
myBindingSource.DataSource = query;
myDataGrid.DataSource = myBindingSource;
Then I create a DataGridTableStyle object and add it to the datagrid. However, it never applies my table style properties I set up because I can't seem set the proper myDataGridTableStyle.MappingName property.
I've searched Google for about 1/2 an hour and keep seeing links to the same question throughout a bunch of different forums (literally the same text, like someone just copied and pasted the question... I hate that...). Anyway, none of the suggestions work, just like the guy says on all the other sites.
So does anybody here know what I need to set the MappingName property to in order to have my TableStyle actually work properly? Where can I grab the name from? (It can't be blank... that only works with a BindingSource that is bound to a DataTable or SqlCeResultSet etc.).
I'm thinking it could be an issue with me using Linq to create an anonymous, more specialized version of the objects with only the fields I need. Should I just try to bind the BindingSource directly to the List object? Or maybe even bind the DataGrid directly to the List object and skip the binding source altogether.
Thanks
PS - C#, Compact Framework v3.5
UPDATE:
I've posted an answer below that solved my problem. Whether or not it's the best approach, it did work. Worth a peek if you're having the same issue I had.
I've found the way to make this work. I'll break it out into sections...
List<myType> myList = new List<myType>(someCapacity);
.
...populate the list with query from database...
.
DataGridTableStyle myDataGridTableStyle = new DatGridtTableStyle();
DataGridTextBoxColumn colA = new DataGridTextBoxColumn();
DataGridTextBoxColumn colB = new DataGridTextBoxColumn();
DataGridTextBoxColumn colC = new DataGridTextBoxColumn();
colA.MappingName = "FieldA";
colA.HeaderText = "Field A";
colA.Width = 50; // or whatever;
colB.MappingName = "FieldB";
.
... etc. (lather, rinse, repeat for each column I want)
.
myDataGridTableStyle.GridColumnStyles.Add(colA);
myDataGridTableStyle.GridColumnStyles.Add(colB);
myDataGridTableStyle.GridColumnStyles.Add(colC);
var query = from i in myList
select new
{
i.FieldA,
i.FieldB,
i.FieldC
};
myBindingSource.DataSource = query.ToList(); // Thanks Marc Gravell
// wasn't sure what else to pass in here, but null worked.
myDataGridTableStyle.MappingName = myBindingSource.GetListName(null);
myDataGrid.TableStyles.Clear(); // Recommended on MSDN in the code examples.
myDataGrid.TablesStyles.Add(myDataGridTableStyle);
myDataGrid.DataSource = myBindingSource;
So basically, the DataGridTableStyle.MappingName needs to know what type of object it is mapping to. Since my object is an anonymous type (created with Linq), I don't know what it is until runtime. After I bind the list of the anonymous type to the binding source, I can use BindingSource.GetListName(null) to get the string representation of the anonymous type.
One thing to note. If I just bound the myList (which is type "myType") directly to the binding source, I could have just used the string "myType" as the value for DataGridTableStyle.MappingName.
Hopefully this is useful to other people!