Gridview in C# dont show data and a big error
<p>I am trying to display my data table with a grid view </p>

<pre><code> protected void show_data(object sender, EventArgs e)
    {
        string str = "Data Source=(LocalDB)\\MSSQLLocalDB;";
        str += "AttachDbFilename=|DataDirectory|DinoData.mdf;";
        str += "Integrated Security= True";
        SqlConnection c;
        c = new SqlConnection(str);
        GV.DataSource = User;
        GV.DataBind();
    }
</code></pre>

<p>the error:</p>

<blockquote>
  <p>An exception of type 'System.InvalidOperationException' occurred in
  System.Web.dll but was not handled in user code</p>
  
  <p>Additional information: Data source is an invalid type.  It must be
  either an IListSource, IEnumerable, or IDataSource.</p>
</blockquote>

<p>user table:</p>

<pre><code>CREATE TABLE [dbo].[User] (
    [Username]  VARCHAR (100) NOT NULL,
    [Pasword]   VARCHAR (100) NOT NULL,
    [FName]     VARCHAR (MAX) NOT NULL,
    [LName]     VARCHAR (MAX) NOT NULL,
    [Location]  VARCHAR (MAX) NOT NULL,
    [Profesion] VARCHAR (MAX) NOT NULL,
    [email]     VARCHAR (MAX) NOT NULL,
    [gender]    VARCHAR (MAX) NOT NULL,
    [money]     INT           NOT NULL,
    [property]  VARCHAR (MAX) NULL,
    [xp]        INT           NOT NULL,
    [level]     INT           NOT NULL,
    PRIMARY KEY CLUSTERED ([Username] ASC)
);
</code></pre>

<p>What should i do?
If I want to show only part of the table with gridview how to do it?</p>