问题
Possible Duplicate:
Datagridview, Only show unique values were Duplicate Cell Values C# 2005
I want to know how to find duplicate rows in a datagridview and if exist only update the data.. i need the code to do that I'm working in C# and .NET framework 2.0 VS2005. I'm not using a database is from query from Active Directory and the values continue repeating.
can someone helpme with this...Thanks
回答1:
You'd need to loop through each row and then through each column. The best way would be to find duplicate before putting them in the DataGridView because there is no built-in way to do it with a DataGridView.
bool isDuplicate;
for(int nbRow = 0; nbRow < DataGridView1.Rows.Count; nbRow++)
{
for(int nbRowCompare = nbRow; nbRowCompare < DataGridView1.Rows.Count; nbRowCompare++)
{
isDuplicate = true;
for(int nbCol = 0; nbCol < DataGridView1.Rows[nbRow].Cells.Count; nbCol++)
{
if(DataGridView1[nbCol, nbRow].Value != DataGridView1[nbCol, nbRowCompare])
{
isDuplicate = false;
break; //Exit for each column if they are not duplicate
}
}
if(isDuplicate)
{
//Do something
}
}
}
Note 1: Your data might have a pattern where you can reduce the number of comparison. This example compare every row against every following rows.
Note 2: If you want to delete duplicates, you should iterate through the rows from the last to the first
回答2:
try {
e.Result = "";
//int count1 = 0;
int val = 6000;
DataTable dt = new DataTable();
dt.Columns.Add(new DataColumn("ComputerName", typeof(String))); //0
dt.Columns.Add(new DataColumn("IP", typeof(String))); //1
dt.Columns.Add(new DataColumn("MAC", typeof(String))); //2
dt.Columns.Add(new DataColumn("Descubierto", typeof(String)));
for (int a = 1; a <= val; a++)
{
counter.Text = Convert.ToString(a);
if (txtWorkGroupName.Text == "") return;
//DataTable dt = new DataTable();
//dt.Clear();
//3
//int i = 0;
try
{
// Datos del grupo WinNT://&&&&(Nombre del grupo de trabajo)
DirectoryEntry DomainEntry = new DirectoryEntry("WinNT://" + txtWorkGroupName.Text + "");
DomainEntry.Children.SchemaFilter.Add("Computer");
///*************************************************
/// Interactuando con PC's dentro del mismo dominio
///*************************************************
foreach (DirectoryEntry machine in DomainEntry.Children)
{
string strMachineName = machine.Name;
string strMACAddress = "";
IPAddress IPAddress;
DateTime discovered;
try
{
IPAddress = getIPByName(machine.Name);
}
catch
{
continue;
}//try/catch
///*************************************************
/// Obtener Mac
///*************************************************
strMACAddress = getMACAddress(IPAddress);
discovered = DateTime.Now;
///*************************************************
/// Manejo de repeticiones en el grid
///*************************************************
bool isDuplicate;
for(int nbRow = 0; nbRow < dt.Rows.Count; nbRow++)
{
for(int nbRowCompare = nbRow; nbRowCompare < dt.Rows.Count; nbRowCompare++)
{
isDuplicate = true;
for(int nbCol = 0; nbCol < dt.Rows[nbRow].Cells.Count; nbCol++)
{
if(dt[nbCol, nbRow].Value != dt [nbCol, nbRowCompare])
{
isDuplicate = false;
break; //Exit for each column if they are not duplicate
}
}
if(isDuplicate)
{
MessageBox.Show("el valor esta duplicado");
}
}
}
///*************************************************
/// this is gonna BE fixed
///*************************************************
DataRow dr = dt.NewRow();
dr[0] = machine.Name;
dr[1] = IPAddress;
dr[2] = strMACAddress;
dr[3] = Convert.ToString(discovered);
dt.Rows.Add(dr);
dgvComputers1.DataSource = dt;
dgvComputers1.Refresh();
//dt.Columns(machine.Name).Unique = true;
//dt.Columns(IPAddress).Unique = true;
//dt.Columns(strMACAddress).Unique = true;
}//foreach loop
// DataView dv = new DataView();
// dv = dt;
Thread.Sleep(2000);
//dt = ((DataView)this.dgvComputers1.DataSource).Table;
//dt.WriteXml(@"testermac.xml");
///*************************************************
/// SETTING DATASOURCE
///*************************************************
// dgvComputers.DataSource = dt;
//goto factor;
//factor:
// if (restart < 20)
//{
// btnScan.PerformClick();
// restart = restart + restart++;
//counter.Text = Convert.ToString(restart);
//}
}//try/catch
catch (Exception ex)
{
{
MessageBox.Show(ex.Message);
}
}
if (backgroundWorker2.CancellationPending)
{
e.Cancel = true;
return;
}
}
}
catch (NullReferenceException ex)
{
MessageBox.Show("error:" + ex);
//tbmessage.Text += "se ha producido un error: " + ex + Environment.NewLine;
//tbmessage.SelectionStart = tbmessage.Text.Length;
//tbmessage.ScrollToCaret();
}
catch (NoNullAllowedException ex)
{
MessageBox.Show("error:" + ex);
}
catch (AccessViolationException ex)
{
MessageBox.Show("error:" + ex);
}
}
来源：https://stackoverflow.com/questions/8717898/datagridview-find-duplicate-rows-and-update-existing-data