how to bind List to DataGridView?

Question

I want to bind a list to datagridview, but the column.count is always 0; The following is the code snippet.

        struct AccRec
        {
            public int PatientId;
            public string PatName;
            public int AccountId;
        }

       public void ShowGrid(object sender, EventArgs e)

       {
                AccRec accRec = new AccRec();
                List<AccRec> accList = new List<AccRec>();
                int i = 0;
                while (i < 3)
                {
                    accRec.PatientId = 1;
                    accRec.PatName = "Surname,FirstName";
                    accRec.AccountId = 1;
                    accList.Add(accRec);
                    i++;
                }

                    dataGridView2.DataSource = accList; //not working

                    //dataGridView2.DataSource = accList.ToList();  //not working

                    //dataGridView2.DataSource = accList.AsEnumerable();  //not working

                    dataGridView2.Columns["PatientId"].DisplayIndex = 0;  //throw an error "Object reference not set to an instance of an object."
                    dataGridView2.Columns["AccountId"].DisplayIndex = 1;
                    dataGridView2.Columns["PatName"].DisplayIndex = 2;

         }

 

Answer 1

hi,

if u dont have any issue with datatable then u can try this way.....

DataTable dt = null;

void FillDt()
{
 if (dt == null)
 {
  dt = new System.Data.DataTable();
  dt.Columns.Add("PatientID");
  dt.Columns.Add("PatientName");
 }

 for(int i = 1; i < 30; i++)
 { 
  dt.Rows.Add( i ,"Name -" + i);
 } 
  
 dataGridView1.DataSource = dt.DefaultView;
}

---

Nagarjuna Dilip

Answer 2

Or add the columns @ design time r runtime and then bind the collection object.

struct AccRec
  {
   public int PatientId;
   public string PatName;
   public int AccountId;
  }

  public void ShowGrid(object sender, EventArgs e)

  {
    AccRec accRec = new AccRec();
    List<AccRec> accList = new List<AccRec>();
    int i = 0;
    while (i < 3)
    {
     accRec.PatientId = 1;
     accRec.PatName = "Surname,FirstName";
     accRec.AccountId = 1;
     accList.Add(accRec);
     i++;
    }
    dataGridView2.Columns.Add("PatientId");
    dataGridView2.Columns.Add("AccountId");
    dataGridView2.Columns.Add("PatName");

    dataGridView2.DataSource = accList; 
    dataGridView2.Columns["PatientId"].DisplayIndex = 0; 
    dataGridView2.Columns["AccountId"].DisplayIndex = 1;
    dataGridView2.Columns["PatName"].DisplayIndex = 2;

   }

---

Nagarjuna Dilip

Answer 3

YOu are missing get,set accessors in the struct - so the data source can get the data from some where. I have rearaged the code a bit, so it looks more "readable", and it works:

namespace Jan28DGV_BindList
{
  public partial class Form1 : Form
  {
    private List<AccRec> accList;
    public Form1()
    {
      InitializeComponent();
      InitializingBS();
      CreatingGrid();
    }

    public void CreatingGrid()
    {
      dataGridView1.AutoGenerateColumns = false;
      dataGridView1.AllowUserToAddRows = false;
      dataGridView1.DataSource = accList;

      DataGridViewTextBoxColumn column1 = new DataGridViewTextBoxColumn();
      column1.Name = "PatientId";
      column1.HeaderText = "Patient id";
      column1.DataPropertyName = "PatientId";
      dataGridView1.Columns.Add(column1);

      DataGridViewTextBoxolumn column2 = new DataGridViewTextBoxColumn();
      column2.Name = "AccountId";
      column2.HeaderText = "Account id";
      column2.DataPropertyName = "AccountId";
      dataGridView1.Columns.Add(column2);

      DataGridViewTextBoxColumn column3 = new DataGridViewTextBoxColumn();
      column3.Name = "PatName";
      column3.HeaderText = "Pat name";
      column3.DataPropertyName = "PatName";
      dataGridView1.Columns.Add(column3);
    }

    public void InitializingBS()
    {
      accList = new List<AccRec>();
      for (int i = 0; i < 3; i++)
      {
        AccRec accRec = new AccRec();
        accRec.PatientId = i + 1;
        accRec.PatName = "Surname,FirstName";
        accRec.AccountId = i + 2;
        accList.Add(accRec);
      }
    }
  }

  struct AccRec
  {
    public int PatientId { get; set; }
    public int AccountId { get; set; }
    public string PatName { get; set; }
  }
}

 

Hope it helps,

Mitja

 

Answer 4

This is the "shorter version of the CreatingGrid() method, so you dont need to create all the columns individually - even if it doesn`t hurt (I always create column in a long way, and set all the necessary). Anyway, here its the code:

    public void CreatingGrid()
    {
      dataGridView1.AutoGenerateColumns = false;
      dataGridView1.AllowUserToAddRows = false;
      dataGridView1.DataSource = accList;

      dataGridView1.Columns.Add("PatientId", "Patient id");
      dataGridView1.Columns.Add("AccountId", "Account id");
      dataGridView1.Columns.Add("PatName", "Pat name");

      dataGridView1.Columns[0].DataPropertyName = "PatientId";
      dataGridView1.Columns[1].DataPropertyName = "AccountId";
      dataGridView1.Columns[2].DataPropertyName = "PatName";
    }

Answer 5

I would do it in the code behind

Page's html

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="GridView1" runat="server">
        </asp:GridView>
    
    </div>
    </form>
</body>
</html>

Code behind file 

using System;

using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Collections.Generic;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        List<Client> lst = new List<Client>();
        lst.Add(new Client("Ken", 39));
        lst.Add(new Client("Cor", 48));

        GridView1.DataSource = lst;
        GridView1.DataBind();
    }
}
public class Client
{

    public Client(string Name, int Age)
    {
        _Name = Name;
        _Age = Age;
    }

    private int _Age;

    public int Age
    {
        get { return _Age; }
        set { _Age = value; }
    }

    private string _Name;

    public string Name
    {
        get { return _Name; }
        set { _Name = value; }
    }
    
}

---

Sankarshan Parida

Answer 6

thank u very much. It works.