你可以直接在后台写代码来控制gridview的,没必要指定它的selectcommand,点击Button1的时候执行这个方法就行了(假定你的button1是一个服务器控件)
public void bind()
{
string text=TextBox1.Text.Trim();
if(text!="") text=" where 列 like '%"+text+"%'";
string sqlstr = "select * from 表"+text;
sqlcon = new SqlConnection(strCon);//strCon是你的连接字符串
SqlDataAdapter myda = new SqlDataAdapter(sqlstr, sqlcon);
DataSet myds = new DataSet();
sqlcon.Open();
myda.Fill(myds, "表");
GridView1.DataSource = myds;
//GridView1.DataKeyNames = new string[] { "id" };//主键
GridView1.DataBind();
sqlcon.Close();
}