How to bind a list of objects of a class to a datagridview whose one field is again an object of some other class?

Question

I have following code in which i have to bind a list of objects of a class to a datagridview. In this class one field is an object of some other class which again have some fields in it.Please refer the code.

public class Test
{
    public string m_field1_Test { get; set; }
    public string m_field2_Test { get; set; }
    public string m_field3_Test { get; set; }
    public string m_field4_Test { get; set; }
    .
    .
    public string m_field100_Test{get; set;}
    public Test1 test1obj;

    public Test()
    {
        m_field1_Test = "field1";
        m_field2_Test = "field2";
        m_field3_Test = "field3";
        m_field4_Test = "field4";
        .
        .
        m_field100_Test = "field100";

        test1obj = new Test1();
    }
}

public class Test1
{
    public string m_field1_Test1;
    public string m_field2_Test1;
    public string m_field3_Test1; 
    .
    .
    .
    public string m_field30_Test1;   

    public Test1()
    {

        m_field1_Test1 = "field1_Test1";
        m_field2_Test1 = "field2_Test1";
        m_field3_Test1 = "field3_Test1"; 
        .
        .
        .
        m_field30_Test1 = "field30_Test1";
    }       
}

On a Button click i am binding a list of Test Objects to dataGridView. Code is as follows.

   private void Button2_Click(object sender, EventArgs e)
    {
        List<Test> listTest = new List<Test>();
        Test obj;
        for (int i = 0; i < 1000000; i++)
        {
            obj = new Test();
            listTest.Add(obj);
        }
        label1.Text = listTest.Count().ToString();
        dataGridView1.DataSource = listTest;
        dataGridView1.BackgroundColor = Color.Beige;                
    }

When i execute this much part only field1 to field4 are appearing in the datagridview. How can i bind it in such a way so that Test1 fields also appear in datagridview in format.I want output something like this.

     field1 | field2  | field3| ....field100|field1_Test1 |field2_Test1|...field30_Test1
            |         |       |             |              |            |
            |         |       |             |              |            |
            |         |       |             |              |            |

Can someone please tell me how to implement this functionality??

Answer 1

Transforming your listTest to an anonymous object before you bind will expose the fields.

var dataSource = listTest.Select(l => new {field1 = l.m_field1_Test, 
                                           field2 = l.m_field2_Test, 
                                           field3 = l.m_field3_Test, 
                                           field4 = l.m_field4_Test,
                                           field1_Test1 = l.test1obj.m_field1_Test1,
                                           field2_Test1 = l.test1obj.m_field2_Test1, 
                                           field3_Test1 = l.test1obj.m_field3_Test1}); 

This would be better accomplished in your loop to 1000000, but I figured that looping to 1000000 is not something you would do in production.

If you wanted to eliminate the for loop, you could do the same with Enumerable.Range :

var dataSource = Enumerable.Range(0, 1000000).Select(...

Also, just a tip, you should avoid putting logic into your event handlers. Pull it into its own method so it can be reused in other places.