input array is longer than the number of columns in this table. c#
//solution 1
//You are trying to add more number of column values to the dataRow,
ds.Rows.Add(TextBox1.Text, TextBox2.Text, TextBox3.Text);
//heck the columns count and add correct number of column values
int colsCount = dt.Columns.Count;
//refer this example:
DataTable dt = new DataTable();
dt.Columns.Add("Col1");
dt.Rows.Add("Col1 Data"); // Valid
dt.Rows.Add("Col1 Data", "Col2 Data"); // invalid , Input array is longer than the number of columns
//solution 2
protected void Add_Click(object sender, EventArgs e)
{
GridView1.Visible = true;
//createnewrow();
ds.Rows.Add(TextBox1.Text, TextBox2.Text, TextBox3.Text);
TextBox1.Text = "";
TextBox2.Text = "";
TextBox3.Text = "";
GridView1.DataSource = ds;
GridView1.DataBind();
GridView1.DataSource = null;
}