在网格视图中显示动态数据

Question

I want to display data in a grid view by dynamically inserting data from textboxes in a database , on click of a button

protected void Button1_Click(object sender, EventArgs e)
    {
        //string Name = TextBox1.Text;
        //string Summary = TextBox2.Text;


        //Inserts the FirstName variable into the db-table
        SqlConnection conn = new SqlConnection("Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\\Database.mdf;Integrated Security=True");
        conn.Open();
        SqlCommand MyCommand = new SqlCommand("INSERT INTO Table2 (Name,Summary) Values ('" + TextBox1.Text + "' , '" + TextBox2.Text + "');",conn);
        MyCommand.ExecuteNonQuery();
        using (SqlCommand cmd = conn.CreateCommand())
        {
            SqlCommand com = new SqlCommand("Select * from Table2", conn);
            SqlDataAdapter sda = new SqlDataAdapter(com);
            DataSet ds = new DataSet();
            sda.Fill(ds);
            //GridView1.DataSource = ds;
            // GridView1.DataBind();
        }
        conn.Close();
        conn.Dispose();
    }

I am not getting any error while running this code but it is not showing any data in the grid view

Answer 1

You have to give datasource as a datatable instead of dataset.

eg:

using (SqlCommand cmd = conn.CreateCommand())
        {
            SqlCommand com = new SqlCommand("Select * from Table2", conn);
            SqlDataAdapter sda = new SqlDataAdapter(com);
            DataTable dt = new DataTable();
            sda.Fill(dt);
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }

Answer 2

Apart from uncommenting those lines of code you need to set the Datasource to the datatable that has been populated not the DataSet...

dataGridView1.DataSource = ds.Tables[0];

On a separate note your initial query is vulnerable to SQL Injection attacks - you should never concatenate user input to form SQL queries, use Parameterised Queries instead eg

    SqlCommand MyCommand = new SqlCommand("INSERT INTO Table2 (Name,Summary) Values (@tb1, @tb2);", conn);
    MyCommand.Parameters.AddWithValue("@tb1", TextBox1.Text);
    MyCommand.Parameters.AddWithValue(@"tb2", TextBox2.Text);
    MyCommand.ExecuteNonQuery();

You are also using a using statement with a sqlcommand that you never use

 using (SqlCommand cmd = conn.CreateCommand())

should really be

using (SqlCommand com = new SqlCommand("Select * from Table2", conn))

Answer 3

You need to uncomment the code where the GridView is getting bind to the data source, as below.

using (SqlCommand cmd = conn.CreateCommand())
        {
            SqlCommand com = new SqlCommand("Select * from Table2", conn);
            SqlDataAdapter sda = new SqlDataAdapter(com);
            DataSet ds = new DataSet();
            sda.Fill(ds);
            GridView1.DataSource = ds.Tables[0];
            GridView1.DataBind();
        }

Aliter: Create a DataTable instead of a DataSet and fill it using the DataAdapter .

DataTable dt=new DataTable();
sda.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();

Try it and let us know if this works for you.

Thanks