选择datagridview单元格或列时如何获取数据

Question

I have 2 datagridview controls in a Windows Forms application.
I would like to get the info of a person when I select first datagridview cell or row to next datagridview:

try
{

    ConnectionStringSettings consettings =                                                        ConfigurationManager.ConnectionStrings["attendancemanagement"];                                                                     
    string connectionString = consettings.ConnectionString;
    SqlConnection con = new SqlConnection(connectionString);
    con.Open();
    adap3 = new SqlDataAdapter(@"SELECT   Date,Attendance,Remarks FROM dailyattendance where employee_id='"+DailyGV.CurrentRow+"'", con);

    ds3 = new DataSet();
    adap3.Fill(ds3, "dailyattendance");
    dataGridView1.DataSource = ds3.Tables[0];

}

Im trying the above code. But it's not working.

Answer 1

I'm not too sure what DailyGV.CurrentRow is but basically you can use the RowHeaderMouseClick ...see MSDN documentation . To use it, hook an event handler to it when initializing the form components (you can use VS designer as well...

dataGridView1.RowHeaderMouseClick += dataGridView1_RowHeaderMouseClick;

void dataGridView1_RowHeaderMouseClick(
object sender, DataGridViewCellMouseEventArgs e)
{
}

this event handler will get fired everytime you select a row header in the DataGridView control which will pass information about the event through an instance of the DataGridViewCellMouseEventArgs class (see MSDN documentation ). This argument has a RowIndex property that provides the index of the row clicked which you can use to retrieve the values of the cells in that row...including the person id (if provided)...for example...

void dataGridView1_RowHeaderMouseClick(
object sender, DataGridViewCellMouseEventArgs e)
{
      string personId = dataGridView1.Rows[e.RowIndex].Cells["PersonId"].Value;

      //TODO: implement your own query to retrieve data for that person id
}

notice that you need to provide a proper column name when access the cells collection indexer... Cells["columnName"]

Answer 2

I will not give any description about the solution because Leo and Arsalan Bhatti has already suggested the solution. I am just telling you how your code should looks like and how it should be written.

string connectionString = consettings.ConnectionString;
using (SqlConnection con = new SqlConnection(connectionString))
{
    try
    {
        con.Open();
        string empID = DailyGV.CurrentRow.Cells["employee_id"].Value.ToString();
        SqlCommand Cmd = con.CreateCommand();
        Cmd.CommandText = "SELECT   Date,Attendance,Remarks FROM dailyattendance where employee_id=@employee_id";
        Cmd.Parameters.Add("@employee_id", SqlDbType.Int).Value = Int32.Parse(empID);
        adap3 = new SqlDataAdapter(Cmd);


        DataTable dt = new DataTable();
        adap3.Fill(dt);
        dataGridView1.DataSource = dt;
        con.Close();
    }    
    catch
    {}
}

Answer 3

try
         {
             cn.Open();
             string query = "select employee_id,Employee_Name,Image_of_Employee from Employee_Details where employee_id='" + dataGridView1.SelectedCells[0].Value.ToString() + "'";
             SqlCommand cmd = new SqlCommand(query, cn);
             SqlDataReader sdr;
             sdr = cmd.ExecuteReader();
             if (sdr.Read())
             {
                 string aa = (string)sdr["employee_id"];
                 string bb = (string)sdr["employee_name"];
                 txtEmployeeID.Text = aa.ToString();
                 txtnameofemployee.Text = bb.ToString();

                 byte[] img=(byte[])sdr["Image_of_employee"];
                 MemoryStream ms=new MemoryStream(img);
                 ms.Seek(0,SeekOrigin.Begin);
                 pictureBox1.Image=Image.FromStream(ms);   cn.Close();
             }


         }
         catch (Exception e1)
         {
             MessageBox.Show(e1.Message);
         }

Answer 4

You are passing the current row's index as employee id in SELECT query. Pass employee id for the selected record. Then it will work fine.