About DataGridView problem！

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C#

MySQL

DataGridView

Hi,all my friends!

When i write program,i run into two problems!
1.After click "Update" button,i click "Show" button,the datagridview will not display data.
2.The second click "Update" button,message box show:"Violation of Concurrency: UpdateCommand affects the expected 1 records in 0".

I don't know how to solution the problems!
I think i need refresh datagridview!

There are a DataGridView control and two Button controls in my program.
following is code.

Form1_Load:

private void Form1_Load(object sender, EventArgs e)
{
    LoadDataGridView_RobotVersion();
}

The "Show" button:

private void button_show_Click(object sender, EventArgs e)
{            
     LoadDataGridView_RobotVersion();      
}

private void LoadDataGridView_RobotVersion()
{            
    this.dataGridView_robotversion.DataSource = null;
            
    setDgStyle_robotversion();

    DataTable robotversion = new DataTable();

    switch (this.comboBox_all_process.SelectedIndex)
    {
        case 0:
              robotversion = dbconn("select STT,Process,Version,Path from tblversion_tstc");
              break;
        case 1:
              robotversion = dbconn("select STT,Process,Version,Path from tblversion_tstc where Process='RFLCA'");
               break;
        case 2:
              robotversion = dbconn("select STT,Process,Version,Path from tblversion_tstc where Process='FINAL'");
                    break;
        case 3:
             robotversion = dbconn("select STT,Process,Version,Path from tblversion_tstc where Process='IMEI'");
             break;
        default:
             robotversion = dbconn("select STT,Process,Version,Path from tblversion_tstc");
             break;
     }            
     this.dataGridView_robotversion.DataSource = robotversion;
}

The "Update" button:

private void button_update_Click(object sender, EventArgs e)
{          
    string strSql = "select STT,Process,Version,Path from tblversion_tstc";
    System.Data.DataTable dtUpdate = new System.Data.DataTable();
    dtUpdate = this.dbconn(strSql);
    dtUpdate.Rows.Clear();

    System.Data.DataTable dtShow = new System.Data.DataTable();

    dtShow = (System.Data.DataTable)this.dataGridView_robotversion.DataSource;

    int p1 = dtShow.Rows.Count;           

    for (int i = 0; i < dtShow.Rows.Count; i++)
    {
        dtUpdate.ImportRow(dtShow.Rows[i]);
    }
    int num = dtUpdate.Rows.Count;
    try
    {                
         this.conn.Open();

         trans = this.conn.BeginTransaction();

         MySqlCommandBuilder CommandBuiler;
         CommandBuiler = new MySqlCommandBuilder(this.adapter);

         this.adapter.Update(dtUpdate);
         trans.Commit();
         his.conn.Close();

     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
         trans.Rollback();
         return;
     }

     dtUpdate.AcceptChanges();
}

 private System.Data.DataTable dbconn(string strSql)
{
     DataTable dtSelect = new DataTable();
           
     try
     {
         conn = new MySqlConnection();
         conn.ConnectionString = MyConnectionString;
         conn.Open();
         this.adapter = new MySqlDataAdapter(strSql, conn);
         int rnt = this.adapter.Fill(dtSelect);
      }
      catch(Exception ex)
      {
         MessageBox.Show(ex.ToString());
      }
      finally
      {
         conn.Close();
      }
            
      return dtSelect;
}