Question

我想刷新数据网格视图，但它不起作用我有一个像这样的刷新方法：

public void Select() 
{
    SqlConnection con = new SqlConnection();
    SqlCommand cmd = new SqlCommand();
    SqlDataAdapter da = new SqlDataAdapter();
    DataTable dt = new DataTable();
    string cs = "server=(local);database=DB_Taxi;trusted_connection=yes;";
    con.ConnectionString = cs;
    con.Open();
    cmd.Connection = con;
    da.SelectCommand = cmd;
    cmd.CommandText = "SELECT * FROM Tbl_Driver";
    da.Fill(dt);
    con.Close();
    grid.DataSource = dt;
}

它在主表格上。我想以另一个名为Add_Driver的形式调用此函数。为此，我在提交按钮中这样说，因为我得到相同的文本框值，并在提交后我想在数据库的数据网格视图中显示它们。我称之为：

private void btnOK_Click(object sender, EventArgs e)
    {
        if (txtID.Text != "" || txtName.Text != "" || txtLastName.Text != "" || txtMobile.Text != "" ||
            txtPhone.Text != "" || txtCar.Text != "" || txtGender.Text != "" || txtAddress.Text != "")
        {
            SqlConnection con = new SqlConnection();
            SqlCommand cmd = new SqlCommand();
            string cs = "server=(local);database=DB_Taxi;trusted_connection=yes;";
            con.ConnectionString = cs;
            con.Open();
            cmd.Connection = con;
            cmd.CommandText = "INSERT INTO Tbl_Driver(DriverID,DName,DLastName,DMobile,DAddress,DCar,DGender,DPhone) VALUES(@ID,@Name,@LastName,@Mobile,@Address,@Car,@Gender,@Phone)";
            cmd.Parameters.AddWithValue("@ID", txtID.Text);
            cmd.Parameters.AddWithValue("@Name", txtName.Text);
            cmd.Parameters.AddWithValue("@LastName", txtLastName.Text);
            cmd.Parameters.AddWithValue("@Mobile", txtMobile.Text);
            cmd.Parameters.AddWithValue("@Address", txtAddress.Text);
            cmd.Parameters.AddWithValue("@Car", txtCar.Text);
            cmd.Parameters.AddWithValue("@Gender", txtGender.Text);
            cmd.Parameters.AddWithValue("@Phone", txtPhone.Text);
            cmd.ExecuteNonQuery();
            con.Close();
            Empty();
            ////////////////////
            Main m = new Main();
            m.Select();
            ////////////////////
            MessageBox.Show("Added");
        }
        else
        {
            MessageBox.Show("Plese complete the form");                
        }            
    }

但数据网格视图的数据不会改变。请帮忙！但是当我在主窗体上调用此方法时，它可以工作但我这样写主要方法：

Select()

Answer 1

试试这个。

public void Select() {
    SqlConnection con = new SqlConnection();
    SqlCommand cmd = new SqlCommand();
    SqlDataAdapter da = new SqlDataAdapter();
    DataTable dt = new DataTable();
    string cs = "server=(local);database=DB_Taxi;trusted_connection=yes;";
    con.ConnectionString = cs;
    con.Open();
    cmd.Connection = con;
    da.SelectCommand = cmd;
    cmd.CommandText = "SELECT * FROM Tbl_Driver";
    da.Fill(dt);
    con.Close();

    //clearing the datasource
    grid.DataSource = null;

    //set the datasource
    grid.DataSource = dt;
}

刷新数据网格视图不起作用

1 个答案: