winForms + DataGridView binding to a List<T>

Question

So, every few months I write something in WinForms to remind myself why I hate it.

Today is the day.

I'm trying to bind a List<T> to a DataGridView control, and I'm not having any luck creating custom bindings (Ugh at all the late bound crap).

I tried:

gvProgramCode.DataBindings.Add(new Binding("Opcode",code,"Opcode"));

It throws an exception, saying that nothing was found by that propertyname.

The name of the column in question is "Opcode". The name of the property in the List<T> is Opcode.

I'm getting angry at winforms again.

EDIT: the problem was that I did not have the bindable fields in my object as properties, just public fields...Apparently it doesn't reflect on fields, just properties.

Answer 1

Is the property on the grid you are binding to Opcode as well?.. if you want to bind directly to List you would just DataSource = list. The databindings allows custom binding. are you trying to do something other than the datasource?

You are getting a bunch of empty rows? do the auto generated columns have names? Have you verified data is in the object (not just string.empty) ?

    class MyObject
    {
        public string Something { get; set; }
        public string Text { get; set; }
        public string Other { get; set; }
    }

    public Form1()
    {
        InitializeComponent();

        List<MyObject> myList = new List<MyObject>();

        for (int i = 0; i < 200; i++)
        {
            string num = i.ToString();
            myList.Add(new MyObject { Something = "Something " + num , Text = "Some Row " + num , Other = "Other " + num  });
        }

        dataGridView1.DataSource = myList;
    }

this should work fine...

Answer 2

I can't really tell what you're trying to do with the example you included, but binding to a generic list of objects is fairly straightforward if you just want to list the objects:

    private BindingSource _gridSource;

    private BindingSource GridSource
    {
        get
        {
            if (_gridSource == null)
                _gridSource = new BindingSource();
            return _gridSource;
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        List<FluffyBunny> list = new List<FluffyBunny>();
        list.Add(new FluffyBunny { Color = "White", EarType = "Long", Name = "Stan" });
        list.Add(new FluffyBunny { Color = "Brown", EarType = "Medium", Name = "Mike" });
        list.Add(new FluffyBunny { Color = "Mottled", EarType = "Short", Name = "Torvald" });

        GridSource.DataSource = list;
        dataGridView1.Columns["EarType"].Visible = false; //Optionally hide a column
        dataGridView1.DataSource = GridSource;

    }

If you only want to display specific properties of the List's type you should be able to make the unwanted column(s) invisible.

Technically, you don't really need to create the BindingSource, but I find it's a whole lot easier when I'm doing updates or changes if I have it.

Hope this helps.

Answer 3

Had the same issue... I had a struct with public fields obviously. nothing in the grid. provided public getters, worked.

Answer 4

Another solution I've found is to use the BindingList collection.

private void Form1_Load(object sender, EventArgs e)
{
   BindingList people= new BindingList {
    new Person {Name="John",Age=23},
    new Person {Name="Lucy",Age=16}
  };

   dataGridView1.DataSource= people;
}

It works fine for me,