GridView doesn't show data

Question

private void fill()
{
  adptr = new OleDbDataAdapter(@"SELECT * FROM LibraryInfo WHERE First_Name='"+LoginName+"'", cn);      
  //LoginName is a string variable for displaying users info after the login          
  ds.Clear();
  adptr.Fill(ds);
  dataGridView1.DataSource = "";
  dataGridView1.DataSource = ds.Tables[0];
}

After the database updated, GridView didn't show data.

Answer 1

Taken from this msdn article on the DataBind Property.

---

ASP EXAMPLE

---

 void Page_Load(Object sender, EventArgs e)
  {

    // This example uses Microsoft SQL Server and connects
    // to the Northwind sample database. The data source needs
    // to be bound to the GridView control only when the 
    // page is first loaded. Thereafter, the values are
    // stored in view state.                      
    if(!IsPostBack)
    {
      // Declare the query string.
      String queryString = 
        "Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]";

      // Run the query and bind the resulting DataSet
      // to the GridView control.
      DataSet ds = GetData(queryString);
      if (ds.Tables.Count > 0)
      {
        AuthorsGridView.DataSource = ds;
        AuthorsGridView.DataBind();
      }
      else
      {
        Message.Text = "Unable to connect to the database.";
      }

    }     

  }

  DataSet GetData(String queryString)
  {

    // Retrieve the connection string stored in the Web.config file.
    String connectionString = ConfigurationManager.ConnectionStrings["NorthWindConnectionString"].ConnectionString;      

    DataSet ds = new DataSet();

    try
    {
      // Connect to the database and run the query.
      SqlConnection connection = new SqlConnection(connectionString);        
      SqlDataAdapter adapter = new SqlDataAdapter(queryString, connection);

      // Fill the DataSet.
      adapter.Fill(ds);

    }
    catch(Exception ex)
    {

      // The connection failed. Display an error message.
      Message.Text = "Unable to connect to the database.";

    }

    return ds;

  }

This snippet shows you how to (a) bind your dataset to a gridview, by assigning it using the Databind method.

The site also says:

Use the DataBind() method to bind data from a data source to the GridView control. This method resolves all data-binding expressions in the active template of the control.

SOLUTION

I would like to reference the line saying:

 AuthorsGridView.DataBind();

which actually binds the data to the control.

SIDE NOTE

To protect yourself from SQLi, you should read up on SQL Parameters, and not direct concatenation.

---

WINFORM EXAMPLE

---

Tutorial was found: here

//create the connection string
string connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\myDatabase.mdb";

//create the database query
string query = "SELECT * FROM MyTable";

//create an OleDbDataAdapter to execute the query
OleDbDataAdapter dAdapter = new OleDbDataAdapter(query, connString);

//create a command builder
OleDbCommandBuilder cBuilder = new OleDbCommandBuilder(dAdapter);

//create a DataTable to hold the query results
DataTable dTable = new DataTable();

//fill the DataTable
dAdapter.Fill(dTable);

Also:

//the DataGridView
DataGridView dgView = new DataGridView();

//BindingSource to sync DataTable and DataGridView
BindingSource bSource = new BindingSource();

//set the BindingSource DataSource
bSource.DataSource = dTable;

//set the DataGridView DataSource
dgView.DataSource = bSource;

Answer 2

Use are missing to call databind method here.Use following code :

 DataAdapter adapter=new DataAdapter(SqlCommand,SqlConn);
 DataTable tbl=new Datatable();
 adapter.Fill(tbl);
 GridView1.DataSource=tbl;
 GridView1.DataBind();//This line is missing in your code

try with this format?