C＃和SQL：如何在不刷新DataGridView的情况下更新表？

Question

I always use

DataGridView.DataSource = (DataTable)tbl; 

But this method is completely refresing the Datagridview something like selectedrows, scrollbar position, backColor etc.. I only want to update cell data from SQL witouth full datagridview refresh

For Example uTorrent has a table like datagridview, and in some cells x KB/s values always refresing but torrentdatagrid is static. there is No scroll moving, no selection dissapearing etc.

Can you help me to do this?

I'm sorry for my bad English. Thanks.

Answer 1

If your table has a primary key, and you want only to update existing/add new rows, you can use DataTable.Merge Method like this:

Initially

dataGridView.DataSource = initial_data_table;

Update

((DataTable)dataGridView.DataSource).Merge(new_data_table);

UPDATE: The method above is the simplest, but as mentioned in the comments, it has side effects due to the Merge method optimizations which suppress the change notifications during the operation and raising ListChanged event with ListChangedType.Reset at the end. So, here is a simple and effective method that does the trick, based on DataTable.LoadDataRow Method :

foreach (var dataRow in newTable.AsEnumerable())
    table.LoadDataRow(dataRow.ItemArray, LoadOption.OverwriteChanges);

And a sample proving that:

using System;
using System.Data;
using System.Linq;
using System.Windows.Forms;

namespace Samples
{
    static class Program
    {
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            var form = new Form();
            var dg = new DataGridView { Dock = DockStyle.Fill, Parent = form };
            var data = GetData();
            dg.DataSource = data;
            var updateTimer = new Timer { Interval = 200, Enabled = true };
            updateTimer.Tick += (sender, e) =>
            {
                foreach (var dr in GetData().AsEnumerable())
                    data.LoadDataRow(dr.ItemArray, LoadOption.OverwriteChanges);
            };
            Application.Run(form);
        }
        static DataTable GetData()
        {
            var dt = new DataTable();
            dt.Columns.Add("Id", typeof(int));
            dt.Columns.Add("Name");
            dt.Columns.Add("Score", typeof(int));
            dt.PrimaryKey = new[] { dt.Columns["Id"] };
            var random = new Random();
            for (int i = 1; i <= 1000; i++)
                dt.Rows.Add(i, "Player #" + i, random.Next(1, 100000));
            return dt;
        }
    }
}

Answer 2

Maybe I slog to explain problem. I m sorry. but, this code solved my problem,

            for (int i = 0; i < dg.Rows.Count; i++)
            {
                for (int j = 1; j < dg.Columns.Count ; j++)
                {
                    dg.Rows[i].Cells[j].Value = NewDataTable.Select("ID=" + dg.Rows[i].Cells[0].Value)[0][j].ToString();
                }
            }

first column is ID Primary key column. I m Updating by a timer and real time passing data to my datagridview. thanks